UI: Grease Pencil Modifier Drag and Drop, Layout Changes

This patch implements the list panel system D7490 for grease pencil
modifiers. It also moves their drawing to a callback in
GpencilModifierTypeInfo in line with the extensible architecture
refactoring goal T75724.

This also adds the "set_error" function for grease pencil modifiers,
which hadn't been copied from mesh modifiers yet.

The implementation is basically exactly the same as for the modifier
patch (9b099c86123fc82).

Thanks to Matias Mendiola (mendio) for providing mockups for many
of the layout changes.

Differential Revision: https://developer.blender.org/D7978

34 files changed, 1973 insertions, 150 deletions

diff --git a/source/blender/blenkernel/BKE_gpencil_modifier.h b/source/blender/blenkernel/BKE_gpencil_modifier.h
index 966d3a98234..ac5f4607838 100644
--- a/source/blender/blenkernel/BKE_gpencil_modifier.h
+++ b/source/blender/blenkernel/BKE_gpencil_modifier.h
@@ -20,12 +20,14 @@
  * \ingroup bke
  */
 
+#include "BLI_compiler_attrs.h"
 #include "DNA_gpencil_modifier_types.h" /* needed for all enum typdefs */
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+struct ARegionType;
 struct Depsgraph;
 struct GpencilModifierData;
 struct ID;
@@ -255,11 +257,17 @@ typedef struct GpencilModifierTypeInfo {
                          struct Object *ob,
                          GreasePencilTexWalkFunc walk,
                          void *userData);
+
+  /* Register the panel types for the modifier's UI. */
+  void (*panelRegister)(struct ARegionType *region_type);
 } GpencilModifierTypeInfo;
 
+#define GPENCIL_MODIFIER_TYPE_PANEL_PREFIX "MOD_PT_gpencil_"
+
 /* Initialize modifier's global data (type info and some common global storages). */
 void BKE_gpencil_modifier_init(void);
 
+void BKE_gpencil_modifierType_panel_id(GpencilModifierType type, char *r_idname);
 const GpencilModifierTypeInfo *BKE_gpencil_modifier_get_info(GpencilModifierType type);
 struct GpencilModifierData *BKE_gpencil_modifier_new(int type);
 void BKE_gpencil_modifier_free_ex(struct GpencilModifierData *md, const int flag);
@@ -276,6 +284,8 @@ void BKE_gpencil_modifier_copydata(struct GpencilModifierData *md,
 void BKE_gpencil_modifier_copydata_ex(struct GpencilModifierData *md,
                                       struct GpencilModifierData *target,
                                       const int flag);
+void BKE_gpencil_modifier_set_error(struct GpencilModifierData *md, const char *format, ...)
+    ATTR_PRINTF_FORMAT(2, 3);
 void BKE_gpencil_modifiers_foreach_ID_link(struct Object *ob,
                                            GreasePencilIDWalkFunc walk,
                                            void *userData);
diff --git a/source/blender/blenkernel/intern/gpencil_modifier.c b/source/blender/blenkernel/intern/gpencil_modifier.c
index 2f8500bd1df..6496b219be1 100644
--- a/source/blender/blenkernel/intern/gpencil_modifier.c
+++ b/source/blender/blenkernel/intern/gpencil_modifier.c
@@ -53,6 +53,9 @@
 
 #include "MOD_gpencil_modifiertypes.h"
 
+#include "CLG_log.h"
+
+static CLG_LogRef LOG = {"bke.gpencil_modifier"};
 static GpencilModifierTypeInfo *modifier_gpencil_types[NUM_GREASEPENCIL_MODIFIER_TYPES] = {NULL};
 
 /* *************************************************** */
@@ -428,9 +431,9 @@ GpencilModifierData *BKE_gpencil_modifier_new(int type)
   BLI_strncpy(md->name, DATA_(mti->name), sizeof(md->name));
 
   md->type = type;
-  md->mode = eGpencilModifierMode_Realtime | eGpencilModifierMode_Render |
-             eGpencilModifierMode_Expanded;
+  md->mode = eGpencilModifierMode_Realtime | eGpencilModifierMode_Render;
   md->flag = eGpencilModifierFlag_OverrideLibrary_Local;
+  md->ui_expand_flag = 1; /* Only expand the parent panel at first. */
 
   if (mti->flags & eGpencilModifierTypeFlag_EnableInEditmode) {
     md->mode |= eGpencilModifierMode_Editmode;
@@ -508,7 +511,8 @@ bool BKE_gpencil_modifier_depends_ontime(GpencilModifierData *md)
 const GpencilModifierTypeInfo *BKE_gpencil_modifier_get_info(GpencilModifierType type)
 {
   /* type unsigned, no need to check < 0 */
-  if (type < NUM_GREASEPENCIL_MODIFIER_TYPES && modifier_gpencil_types[type]->name[0] != '\0') {
+  if (type < NUM_GREASEPENCIL_MODIFIER_TYPES && type > 0 &&
+      modifier_gpencil_types[type]->name[0] != '\0') {
     return modifier_gpencil_types[type];
   }
   else {
@@ -516,6 +520,17 @@ const GpencilModifierTypeInfo *BKE_gpencil_modifier_get_info(GpencilModifierType
   }
 }
 
+/**
+ * Get the idname of the modifier type's panel, which was defined in the #panelRegister callback.
+ */
+void BKE_gpencil_modifierType_panel_id(GpencilModifierType type, char *r_idname)
+{
+  const GpencilModifierTypeInfo *mti = BKE_gpencil_modifier_get_info(type);
+
+  strcpy(r_idname, GPENCIL_MODIFIER_TYPE_PANEL_PREFIX);
+  strcat(r_idname, mti->name);
+}
+
 void BKE_gpencil_modifier_copydata_generic(const GpencilModifierData *md_src,
                                            GpencilModifierData *md_dst)
 {
@@ -553,6 +568,7 @@ void BKE_gpencil_modifier_copydata_ex(GpencilModifierData *md,
 
   target->mode = md->mode;
   target->flag = md->flag;
+  target->ui_expand_flag = md->ui_expand_flag; /* Expand the parent panel by default. */
 
   if (mti->copyData) {
     mti->copyData(md, target);
@@ -587,6 +603,26 @@ GpencilModifierData *BKE_gpencil_modifiers_findby_type(Object *ob, GpencilModifi
   return md;
 }
 
+void BKE_gpencil_modifier_set_error(GpencilModifierData *md, const char *_format, ...)
+{
+  char buffer[512];
+  va_list ap;
+  const char *format = TIP_(_format);
+
+  va_start(ap, _format);
+  vsnprintf(buffer, sizeof(buffer), format, ap);
+  va_end(ap);
+  buffer[sizeof(buffer) - 1] = '\0';
+
+  if (md->error) {
+    MEM_freeN(md->error);
+  }
+
+  md->error = BLI_strdup(buffer);
+
+  CLOG_STR_ERROR(&LOG, md->error);
+}
+
 void BKE_gpencil_modifiers_foreach_ID_link(Object *ob, GreasePencilIDWalkFunc walk, void *userData)
 {
   GpencilModifierData *md = ob->greasepencil_modifiers.first;
diff --git a/source/blender/blenloader/intern/versioning_290.c b/source/blender/blenloader/intern/versioning_290.c
index 0dd1ecd0008..00c73ebe9a7 100644
--- a/source/blender/blenloader/intern/versioning_290.c
+++ b/source/blender/blenloader/intern/versioning_290.c
@@ -268,6 +268,7 @@ void blo_do_versions_290(FileData *fd, Library *UNUSED(lib), Main *bmain)
   {
     /* Keep this block, even when empty. */
 
+    /* Transition to saving expansion for all of a modifier's subpanels. */
     if (!DNA_struct_elem_find(fd->filesdna, "ModifierData", "short", "ui_expand_flag")) {
       for (Object *object = bmain->objects.first; object != NULL; object = object->id.next) {
         LISTBASE_FOREACH (ModifierData *, md, &object->modifiers) {
@@ -302,5 +303,19 @@ void blo_do_versions_290(FileData *fd, Library *UNUSED(lib), Main *bmain)
         }
       }
     }
+
+    /* Transition to saving expansion for all of grease pencil modifier's subpanels. */
+    if (!DNA_struct_elem_find(fd->filesdna, "GpencilModifierData", "short", "ui_expand_flag")) {
+      for (Object *object = bmain->objects.first; object != NULL; object = object->id.next) {
+        LISTBASE_FOREACH (GpencilModifierData *, md, &object->greasepencil_modifiers) {
+          if (md->mode & eGpencilModifierMode_Expanded_DEPRECATED) {
+            md->ui_expand_flag = 1;
+          }
+          else {
+            md->ui_expand_flag = 0;
+          }
+        }
+      }
+    }
   }
 }
diff --git a/source/blender/editors/include/ED_object.h b/source/blender/editors/include/ED_object.h
index ebd7321a46d..0cc926987b2 100644
--- a/source/blender/editors/include/ED_object.h
+++ b/source/blender/editors/include/ED_object.h
@@ -421,6 +421,10 @@ int ED_object_gpencil_modifier_move_down(struct ReportList *reports,
 int ED_object_gpencil_modifier_move_up(struct ReportList *reports,
                                        struct Object *ob,
                                        struct GpencilModifierData *md);
+bool ED_object_gpencil_modifier_move_to_index(struct ReportList *reports,
+                                              struct Object *ob,
+                                              struct GpencilModifierData *md,
+                                              const int index);
 int ED_object_gpencil_modifier_apply(struct Main *bmain,
                                      struct ReportList *reports,
                                      struct Depsgraph *depsgraph,
diff --git a/source/blender/editors/include/UI_interface.h b/source/blender/editors/include/UI_interface.h
index d89e590122c..8e9591c1963 100644
--- a/source/blender/editors/include/UI_interface.h
+++ b/source/blender/editors/include/UI_interface.h
@@ -2004,6 +2004,7 @@ void uiTemplatePathBuilder(uiLayout *layout,
                            struct PointerRNA *root_ptr,
                            const char *text);
 void uiTemplateModifiers(uiLayout *layout, struct bContext *C);
+void uiTemplateGpencilModifiers(uiLayout *layout, struct bContext *C);
 void uiTemplateConstraints(uiLayout *layout, struct bContext *C, bool use_bone_constraints);
 
 uiLayout *uiTemplateGpencilModifier(uiLayout *layout, struct bContext *C, struct PointerRNA *ptr);
diff --git a/source/blender/editors/interface/interface_templates.c b/source/blender/editors/interface/interface_templates.c
index 189441a1f10..56a71970f90 100644
--- a/source/blender/editors/interface/interface_templates.c
+++ b/source/blender/editors/interface/interface_templates.c
@@ -2040,147 +2040,55 @@ void uiTemplateConstraints(uiLayout *UNUSED(layout), bContext *C, bool use_bone_
 /** \name Grease Pencil Modifier Template
  * \{ */
 
-#define ERROR_LIBDATA_MESSAGE TIP_("Can't edit external library data")
-
-static uiLayout *gpencil_draw_modifier(uiLayout *layout, Object *ob, GpencilModifierData *md)
+/**
+ * Function with void * argument for #uiListPanelIDFromDataFunc.
+ */
+static void gpencil_modifier_panel_id(void *md_link, char *r_name)
 {
-  const GpencilModifierTypeInfo *mti = BKE_gpencil_modifier_get_info(md->type);
-  PointerRNA ptr;
-  uiBlock *block;
-  uiLayout *box, *column, *row, *sub;
-  uiLayout *result = NULL;
-
-  /* create RNA pointer */
-  RNA_pointer_create(&ob->id, &RNA_GpencilModifier, md, &ptr);
-
-  column = uiLayoutColumn(layout, true);
-  uiLayoutSetContextPointer(column, "modifier", &ptr);
-
-  /* rounded header ------------------------------------------------------------------- */
-  box = uiLayoutBox(column);
-
-  row = uiLayoutRow(box, false);
-  block = uiLayoutGetBlock(row);
-
-  UI_block_emboss_set(block, UI_EMBOSS_NONE);
-  /* Open/Close .................................  */
-  uiItemR(row, &ptr, "show_expanded", 0, "", ICON_NONE);
-
-  /* modifier-type icon */
-  uiItemL(row, "", RNA_struct_ui_icon(ptr.type));
-  UI_block_emboss_set(block, UI_EMBOSS);
-
-  /* modifier name */
-  if (mti->isDisabled && mti->isDisabled(md, 0)) {
-    uiLayoutSetRedAlert(row, true);
-  }
-  uiItemR(row, &ptr, "name", 0, "", ICON_NONE);
-  uiLayoutSetRedAlert(row, false);
-
-  /* mode enabling buttons */
-  UI_block_align_begin(block);
-  uiItemR(row, &ptr, "show_render", 0, "", ICON_NONE);
-  uiItemR(row, &ptr, "show_viewport", 0, "", ICON_NONE);
-
-  if (mti->flags & eGpencilModifierTypeFlag_SupportsEditmode) {
-    sub = uiLayoutRow(row, true);
-    uiLayoutSetActive(sub, false);
-    uiItemR(sub, &ptr, "show_in_editmode", 0, "", ICON_NONE);
-  }
-
-  UI_block_align_end(block);
-
-  /* Up/Down + Delete ........................... */
-  UI_block_align_begin(block);
-  uiItemO(row, "", ICON_TRIA_UP, "OBJECT_OT_gpencil_modifier_move_up");
-  uiItemO(row, "", ICON_TRIA_DOWN, "OBJECT_OT_gpencil_modifier_move_down");
-  UI_block_align_end(block);
-
-  UI_block_emboss_set(block, UI_EMBOSS_NONE);
-  uiItemO(row, "", ICON_X, "OBJECT_OT_gpencil_modifier_remove");
-  UI_block_emboss_set(block, UI_EMBOSS);
-
-  /* modifier settings (under the header) --------------------------------------------------- */
-  if (md->mode & eGpencilModifierMode_Expanded) {
-    /* apply/convert/copy */
-    box = uiLayoutBox(column);
-    row = uiLayoutRow(box, false);
-
-    /* only here obdata, the rest of modifiers is ob level */
-    UI_block_lock_set(block, BKE_object_obdata_is_libdata(ob), ERROR_LIBDATA_MESSAGE);
-
-    uiLayoutSetOperatorContext(row, WM_OP_INVOKE_DEFAULT);
-
-    sub = uiLayoutRow(row, false);
-    if (mti->flags & eGpencilModifierTypeFlag_NoApply) {
-      uiLayoutSetEnabled(sub, false);
-    }
-    uiItemEnumO(sub,
-                "OBJECT_OT_gpencil_modifier_apply",
-                CTX_IFACE_(BLT_I18NCONTEXT_OPERATOR_DEFAULT, "Apply"),
-                0,
-                "apply_as",
-                MODIFIER_APPLY_DATA);
-
-    UI_block_lock_clear(block);
-    UI_block_lock_set(block, ob && ID_IS_LINKED(ob), ERROR_LIBDATA_MESSAGE);
-
-    uiItemO(row,
-            CTX_IFACE_(BLT_I18NCONTEXT_OPERATOR_DEFAULT, "Copy"),
-            ICON_NONE,
-            "OBJECT_OT_gpencil_modifier_copy");
-
-    /* result is the layout block inside the box,
-     * that we return so that modifier settings can be drawn */
-    result = uiLayoutColumn(box, false);
-    block = uiLayoutAbsoluteBlock(box);
-  }
-
-  /* error messages */
-  if (md->error) {
-    box = uiLayoutBox(column);
-    row = uiLayoutRow(box, false);
-    uiItemL(row, md->error, ICON_ERROR);
-  }
-
-  return result;
+  ModifierData *md = (ModifierData *)md_link;
+  BKE_gpencil_modifierType_panel_id(md->type, r_name);
 }
 
-uiLayout *uiTemplateGpencilModifier(uiLayout *layout, bContext *UNUSED(C), PointerRNA *ptr)
+void uiTemplateGpencilModifiers(uiLayout *UNUSED(layout), bContext *C)
 {
-  Object *ob;
-  GpencilModifierData *md, *vmd;
-  int i;
+  ScrArea *sa = CTX_wm_area(C);
+  ARegion *region = CTX_wm_region(C);
+  Object *ob = get_context_object(C);
+  ListBase *modifiers = &ob->greasepencil_modifiers;
 
-  /* verify we have valid data */
-  if (!RNA_struct_is_a(ptr->type, &RNA_GpencilModifier)) {
-    RNA_warning("Expected modifier on object");
-    return NULL;
-  }
+  bool panels_match = UI_panel_list_matches_data(region, modifiers, gpencil_modifier_panel_id);
 
-  ob = (Object *)ptr->owner_id;
-  md = ptr->data;
+  if (!panels_match) {
+    UI_panels_free_instanced(C, region);
+    GpencilModifierData *md = modifiers->first;
+    for (int i = 0; md; i++, md = md->next) {
+      const GpencilModifierTypeInfo *mti = BKE_gpencil_modifier_get_info(md->type);
+      if (mti->panelRegister) {
+        char panel_idname[MAX_NAME];
+        gpencil_modifier_panel_id(md, panel_idname);
 
-  if (!ob || !(GS(ob->id.name) == ID_OB)) {
-    RNA_warning("Expected modifier on object");
-    return NULL;
+        Panel *new_panel = UI_panel_add_instanced(sa, region, &region->panels, panel_idname, i);
+        if (new_panel != NULL) {
+          UI_panel_set_expand_from_list_data(C, new_panel);
+        }
+      }
+    }
   }
-
-  UI_block_lock_set(uiLayoutGetBlock(layout), (ob && ID_IS_LINKED(ob)), ERROR_LIBDATA_MESSAGE);
-
-  /* find modifier and draw it */
-  vmd = ob->greasepencil_modifiers.first;
-  for (i = 0; vmd; i++, vmd = vmd->next) {
-    if (md == vmd) {
-      return gpencil_draw_modifier(layout, ob, md);
+  else {
+    /* The expansion might have been changed elsewhere, so we still need to set it. */
+    LISTBASE_FOREACH (Panel *, panel, &region->panels) {
+      if ((panel->type != NULL) && (panel->type->flag & PNL_INSTANCED))
+        UI_panel_set_expand_from_list_data(C, panel);
     }
   }
-
-  return NULL;
 }
 
 /** \} */
 
+/** \} */
+
+#define ERROR_LIBDATA_MESSAGE TIP_("Can't edit external library data")
+
 /* -------------------------------------------------------------------- */
 /** \name Grease Pencil Shader FX Template
  * \{ */
diff --git a/source/blender/editors/object/object_gpencil_modifier.c b/source/blender/editors/object/object_gpencil_modifier.c
index 6d0f53cfa1e..99215686280 100644
--- a/source/blender/editors/object/object_gpencil_modifier.c
+++ b/source/blender/editors/object/object_gpencil_modifier.c
@@ -211,6 +211,40 @@ int ED_object_gpencil_modifier_move_down(ReportList *UNUSED(reports),
   return 1;
 }
 
+bool ED_object_gpencil_modifier_move_to_index(ReportList *reports,
+                                              Object *ob,
+                                              GpencilModifierData *md,
+                                              const int index)
+{
+  BLI_assert(md != NULL);
+  BLI_assert(index >= 0);
+  if (index >= BLI_listbase_count(&ob->greasepencil_modifiers)) {
+    BKE_report(reports, RPT_WARNING, "Cannot move modifier beyond the end of the stack");
+    return false;
+  }
+
+  int md_index = BLI_findindex(&ob->greasepencil_modifiers, md);
+  BLI_assert(md_index != -1);
+  if (md_index < index) {
+    /* Move modifier down in list. */
+    for (; md_index < index; md_index++) {
+      if (!ED_object_gpencil_modifier_move_down(reports, ob, md)) {
+        break;
+      }
+    }
+  }
+  else {
+    /* Move modifier up in list. */
+    for (; md_index > index; md_index--) {
+      if (!ED_object_gpencil_modifier_move_up(reports, ob, md)) {
+        break;
+      }
+    }
+  }
+
+  return true;
+}
+
 static int gpencil_modifier_apply_obdata(
     ReportList *reports, Main *bmain, Depsgraph *depsgraph, Object *ob, GpencilModifierData *md)
 {
@@ -596,6 +630,60 @@ void OBJECT_OT_gpencil_modifier_move_down(wmOperatorType *ot)
   gpencil_edit_modifier_properties(ot);
 }
 
+/* ************************* Move to Index Gpencil Modifier Operator ************************* */
+
+static bool gpencil_modifier_move_to_index_poll(bContext *C)
+{
+  return gpencil_edit_modifier_poll(C);
+}
+
+static int gpencil_modifier_move_to_index_exec(bContext *C, wmOperator *op)
+{
+  Object *ob = ED_object_active_context(C);
+  GpencilModifierData *md = gpencil_edit_modifier_property_get(op, ob, 0);
+  int index = RNA_int_get(op->ptr, "index");
+
+  if (!ED_object_gpencil_modifier_move_to_index(op->reports, ob, md, index)) {
+    return OPERATOR_CANCELLED;
+  }
+
+  DEG_id_tag_update(&ob->id, ID_RECALC_GEOMETRY);
+  WM_event_add_notifier(C, NC_OBJECT | ND_MODIFIER, ob);
+
+  return OPERATOR_FINISHED;
+}
+
+static int gpencil_modifier_move_to_index_invoke(bContext *C,
+                                                 wmOperator *op,
+                                                 const wmEvent *UNUSED(event))
+{
+  if (gpencil_edit_modifier_invoke_properties(C, op)) {
+    return gpencil_modifier_move_to_index_exec(C, op);
+  }
+  else {
+    return OPERATOR_CANCELLED;
+  }
+}
+
+void OBJECT_OT_gpencil_modifier_move_to_index(wmOperatorType *ot)
+{
+  ot->name = "Move Active Modifier to Index";
+  ot->idname = "OBJECT_OT_gpencil_modifier_move_to_index";
+  ot->description =
+      "Change the modifier's position in the list so it evaluates after the set number of "
+      "others";
+
+  ot->invoke = gpencil_modifier_move_to_index_invoke;
+  ot->exec = gpencil_modifier_move_to_index_exec;
+  ot->poll = gpencil_modifier_move_to_index_poll;
+
+  /* flags */
+  ot->flag = OPTYPE_REGISTER | OPTYPE_UNDO | OPTYPE_INTERNAL;
+  edit_modifier_properties(ot);
+  RNA_def_int(
+      ot->srna, "index", 0, 0, INT_MAX, "Index", "The index to move the modifier to", 0, INT_MAX);
+}
+
 /************************ apply modifier operator *********************/
 
 static int gpencil_modifier_apply_exec(bContext *C, wmOperator *op)
diff --git a/source/blender/editors/object/object_intern.h b/source/blender/editors/object/object_intern.h
index 1cd91f7c1f3..8feeb3b6067 100644
--- a/source/blender/editors/object/object_intern.h
+++ b/source/blender/editors/object/object_intern.h
@@ -190,6 +190,7 @@ void OBJECT_OT_gpencil_modifier_add(struct wmOperatorType *ot);
 void OBJECT_OT_gpencil_modifier_remove(struct wmOperatorType *ot);
 void OBJECT_OT_gpencil_modifier_move_up(struct wmOperatorType *ot);
 void OBJECT_OT_gpencil_modifier_move_down(struct wmOperatorType *ot);
+void OBJECT_OT_gpencil_modifier_move_to_index(struct wmOperatorType *ot);
 void OBJECT_OT_gpencil_modifier_apply(struct wmOperatorType *ot);
 void OBJECT_OT_gpencil_modifier_copy(struct wmOperatorType *ot);
 
diff --git a/source/blender/editors/object/object_ops.c b/source/blender/editors/object/object_ops.c
index 84bc10f8064..1060a808cfe 100644
--- a/source/blender/editors/object/object_ops.c
+++ b/source/blender/editors/object/object_ops.c
@@ -152,6 +152,7 @@ void ED_operatortypes_object(void)
   WM_operatortype_append(OBJECT_OT_gpencil_modifier_remove);
   WM_operatortype_append(OBJECT_OT_gpencil_modifier_move_up);
   WM_operatortype_append(OBJECT_OT_gpencil_modifier_move_down);
+  WM_operatortype_append(OBJECT_OT_gpencil_modifier_move_to_index);
   WM_operatortype_append(OBJECT_OT_gpencil_modifier_apply);
   WM_operatortype_append(OBJECT_OT_gpencil_modifier_copy);
 
diff --git a/source/blender/editors/space_buttons/space_buttons.c b/source/blender/editors/space_buttons/space_buttons.c
index 187334a5c34..2cc9679dd3f 100644
--- a/source/blender/editors/space_buttons/space_buttons.c
+++ b/source/blender/editors/space_buttons/space_buttons.c
@@ -30,11 +30,10 @@
 #include "BLI_utildefines.h"
 
 #include "BKE_context.h"
+#include "BKE_gpencil_modifier.h" /* Types for registering panels. */
 #include "BKE_modifier.h"
 #include "BKE_screen.h"
 
-#include "DNA_modifier_types.h"
-
 #include "ED_screen.h"
 #include "ED_space_api.h"
 #include "ED_view3d.h" /* To draw toolbar UI. */
@@ -643,6 +642,12 @@ void ED_spacetype_buttons(void)
       mti->panelRegister(art);
     }
   }
+  for (int i = 0; i < NUM_GREASEPENCIL_MODIFIER_TYPES; i++) {
+    const GpencilModifierTypeInfo *mti = BKE_gpencil_modifier_get_info(i);
+    if (mti != NULL && mti->panelRegister != NULL) {
+      mti->panelRegister(art);
+    }
+  }
 
   /* regions: header */
   art = MEM_callocN(sizeof(ARegionType), "spacetype buttons region");
diff --git a/source/blender/gpencil_modifiers/CMakeLists.txt b/source/blender/gpencil_modifiers/CMakeLists.txt
index d3c85b891c6..92aacc74190 100644
--- a/source/blender/gpencil_modifiers/CMakeLists.txt
+++ b/source/blender/gpencil_modifiers/CMakeLists.txt
@@ -25,11 +25,14 @@ set(INC
   ../blenfont
   ../blenkernel
   ../blenlib
+  ../blentranslation
   ../bmesh
   ../depsgraph
+  ../editors/include
   ../makesdna
   ../makesrna
   ../render/extern/include
+  ../windowmanager
   ../../../intern/eigen
   ../../../intern/guardedalloc
 )
@@ -40,6 +43,7 @@ set(INC_SYS
 
 set(SRC
   intern/MOD_gpencil_util.h
+  intern/MOD_gpencil_ui_common.c
 
   intern/MOD_gpencil_util.c
   intern/MOD_gpencilarmature.c
@@ -61,6 +65,7 @@ set(SRC
   intern/MOD_gpenciltime.c
   intern/MOD_gpenciltint.c
 
+  intern/MOD_gpencil_ui_common.h
   MOD_gpencil_modifiertypes.h
 )
 
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencil_ui_common.c b/source/blender/gpencil_modifiers/intern/MOD_gpencil_ui_common.c
new file mode 100644
index 00000000000..93d6dff4c16
--- /dev/null
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencil_ui_common.c
@@ -0,0 +1,460 @@
+/* This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software  Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/** \file
+ * \ingroup modifiers
+ */
+
+#include <string.h>
+
+#include "BLI_listbase.h"
+
+#include "MEM_guardedalloc.h"
+
+#include "BKE_context.h"
+#include "BKE_gpencil_modifier.h"
+#include "BKE_material.h"
+#include "BKE_object.h"
+#include "BKE_screen.h"
+
+#include "DNA_object_force_types.h"
+#include "DNA_object_types.h"
+#include "DNA_particle_types.h"
+#include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
+#include "DNA_space_types.h"
+
+#include "ED_object.h"
+
+#include "BLT_translation.h"
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
+#include "WM_api.h"
+#include "WM_types.h"
+
+#include "MOD_gpencil_ui_common.h" /* Self include */
+
+static Object *get_gpencilmodifier_object(const bContext *C)
+{
+  SpaceProperties *sbuts = CTX_wm_space_properties(C);
+  if (sbuts != NULL && (sbuts->pinid != NULL) && GS(sbuts->pinid->name) == ID_OB) {
+    return (Object *)sbuts->pinid;
+  }
+  else {
+    return CTX_data_active_object(C);
+  }
+}
+
+/**
+ * Poll function so these modifier panels only show for grease pencil objects.
+ */
+static bool gpencil_modifier_ui_poll(const bContext *C, PanelType *UNUSED(pt))
+{
+  Object *ob = get_gpencilmodifier_object(C);
+
+  return (ob != NULL) && (ob->type == OB_GPENCIL);
+}
+
+/* -------------------------------------------------------------------- */
+/** \name Panel Drag and Drop, Expansion Saving
+ * \{ */
+
+/**
+ * Move a modifier to the index it's moved to after a drag and drop.
+ */
+static void gpencil_modifier_reorder(bContext *C, Panel *panel, int new_index)
+{
+  Object *ob = get_gpencilmodifier_object(C);
+
+  GpencilModifierData *md = BLI_findlink(&ob->greasepencil_modifiers, panel->runtime.list_index);
+  PointerRNA props_ptr;
+  wmOperatorType *ot = WM_operatortype_find("OBJECT_OT_gpencil_modifier_move_to_index", false);
+  WM_operator_properties_create_ptr(&props_ptr, ot);
+  RNA_string_set(&props_ptr, "modifier", md->name);
+  RNA_int_set(&props_ptr, "index", new_index);
+  WM_operator_name_call_ptr(C, ot, WM_OP_INVOKE_DEFAULT, &props_ptr);
+  WM_operator_properties_free(&props_ptr);
+}
+
+static short get_gpencil_modifier_expand_flag(const bContext *C, Panel *panel)
+{
+  Object *ob = get_gpencilmodifier_object(C);
+  GpencilModifierData *md = BLI_findlink(&ob->greasepencil_modifiers, panel->runtime.list_index);
+  return md->ui_expand_flag;
+  return 0;
+}
+
+static void set_gpencil_modifier_expand_flag(const bContext *C, Panel *panel, short expand_flag)
+{
+  Object *ob = get_gpencilmodifier_object(C);
+  GpencilModifierData *md = BLI_findlink(&ob->greasepencil_modifiers, panel->runtime.list_index);
+  md->ui_expand_flag = expand_flag;
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Modifier Panel Layouts
+ * \{ */
+
+void gpencil_modifier_masking_panel_draw(const bContext *C,
+                                         Panel *panel,
+                                         bool use_material,
+                                         bool use_vertex)
+{
+  uiLayout *row, *col, *sub;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  PointerRNA ob_ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, &ob_ptr, &ptr);
+
+  PointerRNA obj_data_ptr = RNA_pointer_get(&ob_ptr, "data");
+  bool has_layer = RNA_string_length(&ptr, "layer") != 0;
+
+  uiLayoutSetPropSep(layout, true);
+
+  col = uiLayoutColumn(layout, true);
+  row = uiLayoutRow(col, true);
+  uiItemPointerR(row, &ptr, "layer", &obj_data_ptr, "layers", NULL, ICON_GREASEPENCIL);
+  sub = uiLayoutRow(row, true);
+  uiLayoutSetActive(sub, has_layer);
+  uiLayoutSetPropDecorate(sub, false);
+  uiItemR(sub, &ptr, "invert_layers", 0, "", ICON_ARROW_LEFTRIGHT);
+
+  row = uiLayoutRow(col, true);
+  uiItemR(row, &ptr, "layer_pass", 0, NULL, ICON_NONE);
+  sub = uiLayoutRow(row, true);
+  uiLayoutSetActive(sub, RNA_int_get(&ptr, "layer_pass") != 0);
+  uiLayoutSetPropDecorate(sub, false);
+  uiItemR(sub, &ptr, "invert_layer_pass", 0, "", ICON_ARROW_LEFTRIGHT);
+
+  if (use_material) {
+    PointerRNA material_ptr = RNA_pointer_get(&ptr, "material");
+    bool has_material = !RNA_pointer_is_null(&material_ptr);
+
+    /* Because the Gpencil modifier material property used to be a string in an earlier version of
+     * Blender, we need to check if the material is valid and display it differently if so. */
+    bool valid = false;
+    {
+      if (!has_material) {
+        valid = true;
+      }
+      else {
+        Material *current_material = material_ptr.data;
+        Object *ob = ob_ptr.data;
+        for (int i = 0; i <= ob->totcol; i++) {
+          Material *mat = BKE_object_material_get(ob, i);
+          if (mat == current_material) {
+            valid = true;
+            break;
+          }
+        }
+      }
+    }
+
+    col = uiLayoutColumn(layout, true);
+    row = uiLayoutRow(col, true);
+    uiLayoutSetRedAlert(row, !valid);
+    uiItemPointerR(row,
+                   &ptr,
+                   "material",
+                   &obj_data_ptr,
+                   "materials",
+                   NULL,
+                   valid ? ICON_SHADING_TEXTURE : ICON_ERROR);
+    sub = uiLayoutRow(row, true);
+    uiLayoutSetActive(sub, has_material);
+    uiLayoutSetPropDecorate(sub, false);
+    uiItemR(sub, &ptr, "invert_materials", 0, "", ICON_ARROW_LEFTRIGHT);
+
+    row = uiLayoutRow(col, true);
+    uiItemR(row, &ptr, "pass_index", 0, NULL, ICON_NONE);
+    sub = uiLayoutRow(row, true);
+    uiLayoutSetActive(sub, RNA_int_get(&ptr, "pass_index") != 0);
+    uiLayoutSetPropDecorate(sub, false);
+    uiItemR(sub, &ptr, "invert_material_pass", 0, "", ICON_ARROW_LEFTRIGHT);
+  }
+
+  if (use_vertex) {
+    bool has_vertex_group = RNA_string_length(&ptr, "vertex_group") != 0;
+
+    row = uiLayoutRow(layout, true);
+    uiItemPointerR(row, &ptr, "vertex_group", &ob_ptr, "vertex_groups", NULL, ICON_NONE);
+    sub = uiLayoutRow(row, true);
+    uiLayoutSetActive(sub, has_vertex_group);
+    uiLayoutSetPropDecorate(sub, false);
+    uiItemR(sub, &ptr, "invert_vertex", 0, "", ICON_ARROW_LEFTRIGHT);
+  }
+}
+
+void gpencil_modifier_curve_header_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiItemR(layout, &ptr, "use_custom_curve", 0, NULL, ICON_NONE);
+}
+
+void gpencil_modifier_curve_panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiTemplateCurveMapping(layout, &ptr, "curve", 0, false, false, false, false);
+}
+
+/**
+ * Draw modifier error message.
+ */
+void gpencil_modifier_panel_end(uiLayout *layout, PointerRNA *ptr)
+{
+  GpencilModifierData *md = ptr->data;
+  if (md->error) {
+    uiLayout *row = uiLayoutRow(layout, false);
+    uiItemL(row, IFACE_(md->error), ICON_ERROR);
+  }
+}
+
+/**
+ * Gets RNA pointers for the active object and the panel's modifier data.
+ */
+#define ERROR_LIBDATA_MESSAGE TIP_("External library data")
+void gpencil_modifier_panel_get_property_pointers(const bContext *C,
+                                                  Panel *panel,
+                                                  PointerRNA *r_ob_ptr,
+                                                  PointerRNA *r_md_ptr)
+{
+  Object *ob = get_gpencilmodifier_object(C);
+  GpencilModifierData *md = BLI_findlink(&ob->greasepencil_modifiers, panel->runtime.list_index);
+
+  RNA_pointer_create(&ob->id, &RNA_GpencilModifier, md, r_md_ptr);
+
+  if (r_ob_ptr != NULL) {
+    RNA_pointer_create(&ob->id, &RNA_Object, ob, r_ob_ptr);
+  }
+
+  uiBlock *block = uiLayoutGetBlock(panel->layout);
+  UI_block_lock_clear(block);
+  UI_block_lock_set(block, ob && ID_IS_LINKED(ob), ERROR_LIBDATA_MESSAGE);
+
+  uiLayoutSetContextPointer(panel->layout, "modifier", r_md_ptr);
+}
+
+static void gpencil_modifier_ops_extra_draw(bContext *C, uiLayout *layout, void *md_v)
+{
+  PointerRNA op_ptr;
+  uiLayout *row;
+  GpencilModifierData *md = (GpencilModifierData *)md_v;
+  const GpencilModifierTypeInfo *mti = BKE_gpencil_modifier_get_info(md->type);
+
+  PointerRNA ptr;
+  Object *ob = get_gpencilmodifier_object(C);
+  RNA_pointer_create(&ob->id, &RNA_GpencilModifier, md, &ptr);
+  uiLayoutSetContextPointer(layout, "modifier", &ptr);
+  uiLayoutSetOperatorContext(layout, WM_OP_INVOKE_DEFAULT);
+
+  uiLayoutSetUnitsX(layout, 4.0f);
+
+  /* Apply. */
+  if (!(mti->flags & eGpencilModifierTypeFlag_NoApply)) {
+    uiItemEnumO(layout,
+                "OBJECT_OT_gpencil_modifier_apply",
+                CTX_IFACE_(BLT_I18NCONTEXT_OPERATOR_DEFAULT, "Apply"),
+                ICON_CHECKMARK,
+                "apply_as",
+                MODIFIER_APPLY_DATA);
+  }
+
+  /* Duplicate. */
+  uiItemO(layout,
+          CTX_IFACE_(BLT_I18NCONTEXT_OPERATOR_DEFAULT, "Duplicate"),
+          ICON_DUPLICATE,
+          "OBJECT_OT_gpencil_modifier_copy");
+
+  uiItemS(layout);
+
+  /* Move to first. */
+  row = uiLayoutColumn(layout, false);
+  uiItemFullO(row,
+              "OBJECT_OT_gpencil_modifier_move_to_index",
+              IFACE_("Move to First"),
+              ICON_TRIA_UP,
+              NULL,
+              WM_OP_INVOKE_DEFAULT,
+              0,
+              &op_ptr);
+  RNA_int_set(&op_ptr, "index", 0);
+  if (!md->prev) {
+    uiLayoutSetEnabled(row, false);
+  }
+
+  /* Move to last. */
+  row = uiLayoutColumn(layout, false);
+  uiItemFullO(row,
+              "OBJECT_OT_gpencil_modifier_move_to_index",
+              IFACE_("Move to Last"),
+              ICON_TRIA_DOWN,
+              NULL,
+              WM_OP_INVOKE_DEFAULT,
+              0,
+              &op_ptr);
+  RNA_int_set(&op_ptr, "index", BLI_listbase_count(&ob->greasepencil_modifiers) - 1);
+  if (!md->next) {
+    uiLayoutSetEnabled(row, false);
+  }
+}
+
+static void gpencil_modifier_panel_header(const bContext *C, Panel *panel)
+{
+  uiLayout *row, *sub;
+  uiLayout *layout = panel->layout;
+
+  Object *ob = get_gpencilmodifier_object(C);
+  GpencilModifierData *md = BLI_findlink(&ob->greasepencil_modifiers, panel->runtime.list_index);
+  PointerRNA ptr;
+  RNA_pointer_create(&ob->id, &RNA_GpencilModifier, md, &ptr);
+  uiLayoutSetContextPointer(panel->layout, "modifier", &ptr);
+
+  const GpencilModifierTypeInfo *mti = BKE_gpencil_modifier_get_info(md->type);
+  bool narrow_panel = (panel->sizex < UI_UNIT_X * 9 && panel->sizex != 0);
+
+  /* Modifier Icon. */
+  row = uiLayoutRow(layout, false);
+  if (mti->isDisabled && mti->isDisabled(md, 0)) {
+    uiLayoutSetRedAlert(row, true);
+  }
+  uiItemL(row, "", RNA_struct_ui_icon(ptr.type));
+
+  /* Modifier name. */
+  row = uiLayoutRow(layout, true);
+  if (!narrow_panel) {
+    uiItemR(row, &ptr, "name", 0, "", ICON_NONE);
+  }
+  else {
+    uiLayoutSetAlignment(row, UI_LAYOUT_ALIGN_RIGHT);
+  }
+
+  /* Display mode buttons. */
+  if (mti->flags & eGpencilModifierTypeFlag_SupportsEditmode) {
+    sub = uiLayoutRow(row, true);
+    uiItemR(sub, &ptr, "show_in_editmode", 0, "", ICON_NONE);
+  }
+  uiItemR(row, &ptr, "show_viewport", 0, "", ICON_NONE);
+  uiItemR(row, &ptr, "show_render", 0, "", ICON_NONE);
+
+  /* Extra operators. */
+  // row = uiLayoutRow(layout, true);
+  uiItemMenuF(row, "", ICON_DOWNARROW_HLT, gpencil_modifier_ops_extra_draw, md);
+
+  /* Remove button. */
+  sub = uiLayoutRow(row, true);
+  uiLayoutSetEmboss(sub, UI_EMBOSS_NONE);
+  uiItemO(sub, "", ICON_X, "OBJECT_OT_gpencil_modifier_remove");
+
+  /* Extra padding. */
+  uiItemS(layout);
+}
+
+/** \} */
+
+/* -------------------------------------------------------------------- */
+/** \name Modifier Registration Helpers
+ * \{ */
+
+/**
+ * Create a panel in the context's region
+ */
+PanelType *gpencil_modifier_panel_register(ARegionType *region_type,
+                                           GpencilModifierType type,
+                                           PanelDrawFn draw)
+{
+
+  /* Get the name for the modifier's panel. */
+  char panel_idname[BKE_ST_MAXNAME];
+  BKE_gpencil_modifierType_panel_id(type, panel_idname);
+
+  PanelType *panel_type = MEM_callocN(sizeof(PanelType), panel_idname);
+
+  strcpy(panel_type->idname, panel_idname);
+  strcpy(panel_type->label, "");
+  strcpy(panel_type->context, "modifier");
+  strcpy(panel_type->translation_context, BLT_I18NCONTEXT_DEFAULT_BPYRNA);
+
+  panel_type->draw_header = gpencil_modifier_panel_header;
+  panel_type->draw = draw;
+  panel_type->poll = gpencil_modifier_ui_poll;
+
+  /* Give the panel the special flag that says it was built here and corresponds to a
+   * modifer rather than a PanelType. */
+  panel_type->flag = PNL_LAYOUT_HEADER_EXPAND | PNL_DRAW_BOX | PNL_INSTANCED;
+  panel_type->reorder = gpencil_modifier_reorder;
+  panel_type->get_list_data_expand_flag = get_gpencil_modifier_expand_flag;
+  panel_type->set_list_data_expand_flag = set_gpencil_modifier_expand_flag;
+
+  BLI_addtail(&region_type->paneltypes, panel_type);
+
+  return panel_type;
+}
+
+/**
+ * Add a child panel to the parent.
+ *
+ * \note To create the panel type's idname, it appends the \a name argument to the \a parent's
+ * idname.
+ */
+PanelType *gpencil_modifier_subpanel_register(ARegionType *region_type,
+                                              const char *name,
+                                              const char *label,
+                                              PanelDrawFn draw_header,
+                                              PanelDrawFn draw,
+                                              PanelType *parent)
+{
+  /* Create the subpanel's ID name. */
+  char panel_idname[BKE_ST_MAXNAME];
+  strcpy(panel_idname, parent->idname);
+  strcat(panel_idname, "_");
+  strcat(panel_idname, name);
+
+  PanelType *panel_type = MEM_callocN(sizeof(PanelType), panel_idname);
+
+  strcpy(panel_type->idname, panel_idname);
+  strcpy(panel_type->label, label);
+  strcpy(panel_type->context, "modifier");
+  strcpy(panel_type->translation_context, BLT_I18NCONTEXT_DEFAULT_BPYRNA);
+
+  panel_type->draw_header = draw_header;
+  panel_type->draw = draw;
+  panel_type->poll = gpencil_modifier_ui_poll;
+  panel_type->flag = (PNL_DEFAULT_CLOSED | PNL_DRAW_BOX);
+
+  BLI_assert(parent != NULL);
+  strcpy(panel_type->parent_id, parent->idname);
+  panel_type->parent = parent;
+  BLI_addtail(&parent->children, BLI_genericNodeN(panel_type));
+  BLI_addtail(&region_type->paneltypes, panel_type);
+
+  return panel_type;
+}
+
+/** \} */
\ No newline at end of file
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencil_ui_common.h b/source/blender/gpencil_modifiers/intern/MOD_gpencil_ui_common.h
new file mode 100644
index 00000000000..9c6edb51d63
--- /dev/null
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencil_ui_common.h
@@ -0,0 +1,66 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ */
+
+/** \file
+ * \ingroup modifiers
+ */
+
+#ifndef __MOD_UI_COMMON__GPENCIL_H__
+#define __MOD_UI_COMMON__GPENCIL_H__
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include "MOD_gpencil_modifiertypes.h"
+
+struct ARegionType;
+struct bContext;
+struct PanelType;
+struct uiLayout;
+typedef void (*PanelDrawFn)(const bContext *, Panel *);
+
+void gpencil_modifier_masking_panel_draw(const bContext *C,
+                                         Panel *panel,
+                                         bool use_material,
+                                         bool use_vertex);
+
+void gpencil_modifier_curve_header_draw(const bContext *C, Panel *panel);
+void gpencil_modifier_curve_panel_draw(const bContext *C, Panel *panel);
+
+void gpencil_modifier_panel_end(struct uiLayout *layout, PointerRNA *ptr);
+
+void gpencil_modifier_panel_get_property_pointers(const bContext *C,
+                                                  struct Panel *panel,
+                                                  struct PointerRNA *r_ob_ptr,
+                                                  struct PointerRNA *r_ptr);
+
+PanelType *gpencil_modifier_panel_register(struct ARegionType *region_type,
+                                           GpencilModifierType type,
+                                           PanelDrawFn draw);
+
+struct PanelType *gpencil_modifier_subpanel_register(struct ARegionType *region_type,
+                                                     const char *name,
+                                                     const char *label,
+                                                     PanelDrawFn draw_header,
+                                                     PanelDrawFn draw,
+                                                     struct PanelType *parent);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* __MOD_UI_COMMON__GPENCIL_H__ */
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c
index 776e5521179..6b7c1c41e12 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilarmature.c
@@ -28,6 +28,8 @@
 
 #include "BLI_math.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_armature_types.h"
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
@@ -35,8 +37,10 @@
 #include "DNA_modifier_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_armature.h"
+#include "BKE_context.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_gpencil_modifier.h"
@@ -44,10 +48,17 @@
 #include "BKE_main.h"
 #include "BKE_modifier.h"
 #include "BKE_scene.h"
+#include "BKE_screen.h"
 
 #include "MEM_guardedalloc.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 #include "DEG_depsgraph.h"
@@ -181,6 +192,39 @@ static void foreachObjectLink(GpencilModifierData *md,
   walk(userData, ob, &mmd->object, IDWALK_CB_NOP);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *sub, *row, *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  PointerRNA ob_ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, &ob_ptr, &ptr);
+
+  bool has_vertex_group = RNA_string_length(&ptr, "vertex_group") != 0;
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "object", 0, NULL, ICON_NONE);
+  row = uiLayoutRow(layout, true);
+  uiItemPointerR(row, &ptr, "vertex_group", &ob_ptr, "vertex_groups", NULL, ICON_NONE);
+  sub = uiLayoutRow(row, true);
+  uiLayoutSetActive(sub, has_vertex_group);
+  uiLayoutSetPropDecorate(sub, false);
+  uiItemR(sub, &ptr, "invert_vertex_group", 0, "", ICON_ARROW_LEFTRIGHT);
+
+  col = uiLayoutColumnWithHeading(layout, true, "Bind to");
+  uiItemR(col, &ptr, "use_vertex_groups", 0, IFACE_("Vertex Groups"), ICON_NONE);
+  uiItemR(col, &ptr, "use_bone_envelopes", 0, IFACE_("Bone Envelopes"), ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  gpencil_modifier_panel_register(region_type, eGpencilModifierType_Armature, panel_draw);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Armature = {
     /* name */ "Armature",
     /* structName */ "ArmatureGpencilModifierData",
@@ -202,4 +246,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Armature = {
     /* foreachObjectLink */ foreachObjectLink,
     /* foreachIDLink */ NULL,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilarray.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilarray.c
index da4c1f71f44..d92721f887f 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilarray.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilarray.c
@@ -35,12 +35,16 @@
 #include "BLI_math.h"
 #include "BLI_rand.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_collection.h"
+#include "BKE_context.h"
 #include "BKE_global.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_geom.h"
@@ -51,12 +55,19 @@
 #include "BKE_modifier.h"
 #include "BKE_object.h"
 #include "BKE_scene.h"
+#include "BKE_screen.h"
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
 
 #include "DEG_depsgraph.h"
 #include "DEG_depsgraph_build.h"
 #include "DEG_depsgraph_query.h"
 
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 typedef struct tmpStrokes {
@@ -78,6 +89,9 @@ static void initData(GpencilModifierData *md)
   gpmd->flag |= GP_ARRAY_USE_RELATIVE;
   gpmd->seed = 1;
   gpmd->material = NULL;
+
+  /* Open the first subpanel too, because it's activated by default. */
+  md->ui_expand_flag = (1 << 0) | (1 << 1);
 }
 
 static void copyData(const GpencilModifierData *md, GpencilModifierData *target)
@@ -330,6 +344,143 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   foreachObjectLink(md, ob, (ObjectWalkFunc)walk, userData);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "count", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "replace_material", 0, IFACE_("Material Override"), ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void relative_offset_header_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiItemR(layout, &ptr, "use_relative_offset", 0, IFACE_("Relative Offset"), ICON_NONE);
+}
+
+static void relative_offset_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiLayout *col = uiLayoutColumn(layout, false);
+
+  uiLayoutSetActive(col, RNA_boolean_get(&ptr, "use_relative_offset"));
+  uiItemR(col, &ptr, "relative_offset", 0, IFACE_("Factor"), ICON_NONE);
+}
+
+static void constant_offset_header_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiItemR(layout, &ptr, "use_constant_offset", 0, IFACE_("Constant Offset"), ICON_NONE);
+}
+
+static void constant_offset_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiLayout *col = uiLayoutColumn(layout, false);
+
+  uiLayoutSetActive(col, RNA_boolean_get(&ptr, "use_constant_offset"));
+  uiItemR(col, &ptr, "constant_offset", 0, IFACE_("Distance"), ICON_NONE);
+}
+
+/**
+ * Object offset in a subpanel for consistency with the other offset types.
+ */
+static void object_offset_header_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiItemR(layout, &ptr, "use_object_offset", 0, NULL, ICON_NONE);
+}
+
+static void object_offset_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiLayout *col = uiLayoutColumn(layout, false);
+
+  uiLayoutSetActive(col, RNA_boolean_get(&ptr, "use_object_offset"));
+  uiItemR(col, &ptr, "offset_object", 0, NULL, ICON_NONE);
+}
+
+static void random_panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "random_offset", 0, IFACE_("Offset"), ICON_NONE);
+  uiItemR(layout, &ptr, "random_rotation", 0, IFACE_("Rotation"), ICON_NONE);
+  uiItemR(layout, &ptr, "random_scale", 0, IFACE_("Scale"), ICON_NONE);
+  uiItemR(layout, &ptr, "seed", 0, NULL, ICON_NONE);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Array, panel_draw);
+  gpencil_modifier_subpanel_register(region_type,
+                                     "relative_offset",
+                                     "",
+                                     relative_offset_header_draw,
+                                     relative_offset_draw,
+                                     panel_type);
+  gpencil_modifier_subpanel_register(region_type,
+                                     "constant_offset",
+                                     "",
+                                     constant_offset_header_draw,
+                                     constant_offset_draw,
+                                     panel_type);
+  gpencil_modifier_subpanel_register(
+      region_type, "object_offset", "", object_offset_header_draw, object_offset_draw, panel_type);
+  gpencil_modifier_subpanel_register(
+      region_type, "randomize", "Randomize", NULL, random_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Array = {
     /* name */ "Array",
     /* structName */ "ArrayGpencilModifierData",
@@ -352,4 +503,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Array = {
     /* foreachObjectLink */ foreachObjectLink,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilbuild.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilbuild.c
index 71a051629d8..54ed2ffafe1 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilbuild.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilbuild.c
@@ -30,20 +30,31 @@
 #include "BLI_blenlib.h"
 #include "BLI_math.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
+#include "BKE_context.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_gpencil_modifier.h"
+#include "BKE_screen.h"
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
 
 #include "DEG_depsgraph.h"
 #include "DEG_depsgraph_query.h"
 
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -537,6 +548,88 @@ static void generateStrokes(GpencilModifierData *md, Depsgraph *depsgraph, Objec
   }
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *row, *sub;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  PointerRNA ob_ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, &ob_ptr, &ptr);
+
+  int mode = RNA_enum_get(&ptr, "mode");
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "mode", 0, NULL, ICON_NONE);
+  if (mode == GP_BUILD_MODE_CONCURRENT) {
+    uiItemR(layout, &ptr, "concurrent_time_alignment", 0, NULL, ICON_NONE);
+  }
+
+  uiItemS(layout);
+
+  uiItemR(layout, &ptr, "transition", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "start_delay", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "length", 0, IFACE_("Frames"), ICON_NONE);
+
+  uiItemS(layout);
+
+  row = uiLayoutRowWithHeading(layout, true, IFACE_("Use Factor"));
+  uiItemR(row, &ptr, "use_percentage", 0, "", ICON_NONE);
+  sub = uiLayoutRow(row, true);
+  uiLayoutSetActive(sub, RNA_boolean_get(&ptr, "use_percentage"));
+  uiItemR(sub, &ptr, "percentage_factor", 0, "", ICON_NONE);
+
+  /* Check for incompatible time modifier. */
+  Object *ob = ob_ptr.data;
+  GpencilModifierData *md = ptr.data;
+  if (BKE_gpencil_modifiers_findby_type(ob, eGpencilModifierType_Time) != NULL) {
+    BKE_gpencil_modifier_set_error(md, "Build and Time Offset modifiers are incompatible");
+  }
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void frame_range_header_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiItemR(layout, &ptr, "use_restrict_frame_range", 0, IFACE_("Custom Range"), ICON_NONE);
+}
+
+static void frame_range_panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  col = uiLayoutColumn(layout, false);
+  uiItemR(col, &ptr, "frame_start", 0, IFACE_("Start"), ICON_NONE);
+  uiItemR(col, &ptr, "frame_end", 0, IFACE_("End"), ICON_NONE);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, false, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Build, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "frame_range", "", frame_range_header_draw, frame_range_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(
+      region_type, "_mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 /* ******************************************** */
 
 GpencilModifierTypeInfo modifierType_Gpencil_Build = {
@@ -561,4 +654,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Build = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ NULL,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilcolor.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilcolor.c
index 14125d5c8d4..03137a5cf23 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilcolor.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilcolor.c
@@ -29,22 +29,33 @@
 #include "BLI_math_color.h"
 #include "BLI_math_vector.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_colortools.h"
+#include "BKE_context.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_modifier.h"
 #include "BKE_lib_query.h"
 #include "BKE_main.h"
 #include "BKE_material.h"
+#include "BKE_screen.h"
+
+#include "UI_interface.h"
+#include "UI_resources.h"
+
 #include "BKE_modifier.h"
+#include "RNA_access.h"
 
 #include "DEG_depsgraph.h"
 
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -186,6 +197,42 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "modify_color", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "hue", UI_ITEM_R_SLIDER, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "saturation", UI_ITEM_R_SLIDER, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "value", UI_ITEM_R_SLIDER, NULL, ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Color, panel_draw);
+  PanelType *mask_panel_type = gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(region_type,
+                                     "curve",
+                                     "",
+                                     gpencil_modifier_curve_header_draw,
+                                     gpencil_modifier_curve_panel_draw,
+                                     mask_panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Color = {
     /* name */ "Hue/Saturation",
     /* structName */ "ColorGpencilModifierData",
@@ -208,4 +255,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Color = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilhook.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilhook.c
index d39c94e06d5..a0987aafcd2 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilhook.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilhook.c
@@ -28,15 +28,19 @@
 
 #include "BLI_math.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_modifier_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_action.h"
 #include "BKE_colortools.h"
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_gpencil_modifier.h"
@@ -45,10 +49,17 @@
 #include "BKE_main.h"
 #include "BKE_modifier.h"
 #include "BKE_scene.h"
+#include "BKE_screen.h"
 
 #include "MEM_guardedalloc.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 #include "DEG_depsgraph.h"
@@ -345,6 +356,81 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   foreachObjectLink(md, ob, (ObjectWalkFunc)walk, userData);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *sub, *row, *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  PointerRNA ob_ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, &ob_ptr, &ptr);
+
+  PointerRNA hook_object_ptr = RNA_pointer_get(&ptr, "object");
+  bool has_vertex_group = RNA_string_length(&ptr, "vertex_group") != 0;
+
+  uiLayoutSetPropSep(layout, true);
+
+  col = uiLayoutColumn(layout, false);
+  uiItemR(col, &ptr, "object", 0, NULL, ICON_NONE);
+  if (!RNA_pointer_is_null(&hook_object_ptr) &&
+      RNA_enum_get(&hook_object_ptr, "type") == OB_ARMATURE) {
+    PointerRNA hook_object_data_ptr = RNA_pointer_get(&hook_object_ptr, "data");
+    uiItemPointerR(
+        col, &ptr, "subtarget", &hook_object_data_ptr, "bones", IFACE_("Bone"), ICON_NONE);
+  }
+
+  row = uiLayoutRow(layout, true);
+  uiItemPointerR(row, &ptr, "vertex_group", &ob_ptr, "vertex_groups", NULL, ICON_NONE);
+  sub = uiLayoutRow(row, true);
+  uiLayoutSetActive(sub, has_vertex_group);
+  uiLayoutSetPropSep(sub, false);
+  uiItemR(sub, &ptr, "invert_vertex", 0, "", ICON_ARROW_LEFTRIGHT);
+
+  uiItemR(layout, &ptr, "strength", UI_ITEM_R_SLIDER, NULL, ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void falloff_panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *row;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  bool use_falloff = RNA_enum_get(&ptr, "falloff_type") != eWarp_Falloff_None;
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "falloff_type", 0, IFACE_("Type"), ICON_NONE);
+
+  row = uiLayoutRow(layout, false);
+  uiLayoutSetActive(row, use_falloff);
+  uiItemR(row, &ptr, "falloff_radius", 0, NULL, ICON_NONE);
+
+  uiItemR(layout, &ptr, "use_falloff_uniform", 0, NULL, ICON_NONE);
+
+  if (RNA_enum_get(&ptr, "falloff_type") == eWarp_Falloff_Curve) {
+    uiTemplateCurveMapping(layout, &ptr, "falloff_curve", 0, false, false, false, false);
+  }
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Hook, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "falloff", "Falloff", NULL, falloff_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Hook = {
     /* name */ "Hook",
     /* structName */ "HookGpencilModifierData",
@@ -367,4 +453,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Hook = {
     /* foreachObjectLink */ foreachObjectLink,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencillattice.c b/source/blender/gpencil_modifiers/intern/MOD_gpencillattice.c
index 92b35f390f8..0f5fc4d5cf6 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencillattice.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencillattice.c
@@ -26,12 +26,16 @@
 #include "BLI_listbase.h"
 #include "BLI_utildefines.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_gpencil_modifier.h"
@@ -41,10 +45,17 @@
 #include "BKE_main.h"
 #include "BKE_modifier.h"
 #include "BKE_scene.h"
+#include "BKE_screen.h"
 
 #include "MEM_guardedalloc.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 #include "DEG_depsgraph.h"
@@ -208,6 +219,54 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   foreachObjectLink(md, ob, (ObjectWalkFunc)walk, userData);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *sub, *row, *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  PointerRNA ob_ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, &ob_ptr, &ptr);
+
+  PointerRNA hook_object_ptr = RNA_pointer_get(&ptr, "object");
+  bool has_vertex_group = RNA_string_length(&ptr, "vertex_group") != 0;
+
+  uiLayoutSetPropSep(layout, true);
+
+  col = uiLayoutColumn(layout, false);
+  uiItemR(col, &ptr, "object", 0, NULL, ICON_NONE);
+  if (!RNA_pointer_is_null(&hook_object_ptr) &&
+      RNA_enum_get(&hook_object_ptr, "type") == OB_ARMATURE) {
+    PointerRNA hook_object_data_ptr = RNA_pointer_get(&hook_object_ptr, "data");
+    uiItemPointerR(
+        col, &ptr, "subtarget", &hook_object_data_ptr, "bones", IFACE_("Bone"), ICON_NONE);
+  }
+
+  row = uiLayoutRow(layout, true);
+  uiItemPointerR(row, &ptr, "vertex_group", &ob_ptr, "vertex_groups", NULL, ICON_NONE);
+  sub = uiLayoutRow(row, true);
+  uiLayoutSetActive(sub, has_vertex_group);
+  uiLayoutSetPropSep(sub, false);
+  uiItemR(sub, &ptr, "invert_vertex", 0, "", ICON_ARROW_LEFTRIGHT);
+
+  uiItemR(layout, &ptr, "strength", UI_ITEM_R_SLIDER, NULL, ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Lattice, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Lattice = {
     /* name */ "Lattice",
     /* structName */ "LatticeGpencilModifierData",
@@ -230,4 +289,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Lattice = {
     /* foreachObjectLink */ foreachObjectLink,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilmirror.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilmirror.c
index 10f0dd763b1..581eaa886d8 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilmirror.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilmirror.c
@@ -28,12 +28,16 @@
 #include "BLI_listbase.h"
 #include "BLI_math.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_modifier.h"
@@ -43,10 +47,17 @@
 #include "BKE_modifier.h"
 #include "BKE_object.h"
 #include "BKE_scene.h"
+#include "BKE_screen.h"
 
 #include "MEM_guardedalloc.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 #include "DEG_depsgraph.h"
@@ -254,6 +265,40 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   foreachObjectLink(md, ob, (ObjectWalkFunc)walk, userData);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *row;
+  uiLayout *layout = panel->layout;
+  int toggles_flag = UI_ITEM_R_TOGGLE | UI_ITEM_R_FORCE_BLANK_DECORATE;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  row = uiLayoutRowWithHeading(layout, true, IFACE_("Axis"));
+  uiItemR(row, &ptr, "x_axis", toggles_flag, NULL, ICON_NONE);
+  uiItemR(row, &ptr, "y_axis", toggles_flag, NULL, ICON_NONE);
+  uiItemR(row, &ptr, "z_axis", toggles_flag, NULL, ICON_NONE);
+
+  uiItemR(layout, &ptr, "object", 0, NULL, ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Mirror, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Mirror = {
     /* name */ "Mirror",
     /* structName */ "MirrorGpencilModifierData",
@@ -276,4 +321,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Mirror = {
     /* foreachObjectLink */ foreachObjectLink,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilmultiply.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilmultiply.c
index 22e46626a13..619c37015e4 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilmultiply.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilmultiply.c
@@ -29,6 +29,7 @@
 #include "DNA_gpencil_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BLI_alloca.h"
 #include "BLI_blenlib.h"
@@ -37,6 +38,8 @@
 #include "BLI_rand.h"
 #include "BLI_utildefines.h"
 
+#include "BLT_translation.h"
+
 #include "BKE_collection.h"
 #include "BKE_context.h"
 #include "BKE_global.h"
@@ -51,6 +54,7 @@
 #include "BKE_modifier.h"
 #include "BKE_object.h"
 #include "BKE_scene.h"
+#include "BKE_screen.h"
 
 #include "bmesh.h"
 #include "bmesh_tools.h"
@@ -59,7 +63,13 @@
 #include "DEG_depsgraph_build.h"
 #include "DEG_depsgraph_query.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -305,8 +315,71 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "duplicates", 0, NULL, ICON_NONE);
+
+  col = uiLayoutColumn(layout, false);
+  uiLayoutSetActive(layout, RNA_int_get(&ptr, "duplicates") > 0);
+  uiItemR(col, &ptr, "distance", 0, NULL, ICON_NONE);
+  uiItemR(col, &ptr, "offset", UI_ITEM_R_SLIDER, NULL, ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void fade_header_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiItemR(layout, &ptr, "use_fade", 0, NULL, ICON_NONE);
+}
+
+static void fade_panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiLayoutSetActive(layout, RNA_boolean_get(&ptr, "use_fade"));
+
+  col = uiLayoutColumn(layout, false);
+  uiItemR(col, &ptr, "fading_center", 0, NULL, ICON_NONE);
+  uiItemR(col, &ptr, "fading_thickness", UI_ITEM_R_SLIDER, NULL, ICON_NONE);
+  uiItemR(col, &ptr, "fading_opacity", UI_ITEM_R_SLIDER, NULL, ICON_NONE);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Multiply, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "fade", "", fade_header_draw, fade_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Multiply = {
-    /* name */ "Multiple Strokes",
+    /* name */ "MultipleStrokes",
     /* structName */ "MultiplyGpencilModifierData",
     /* structSize */ sizeof(MultiplyGpencilModifierData),
     /* type */ eGpencilModifierTypeType_Gpencil,
@@ -327,4 +400,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Multiply = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilnoise.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilnoise.c
index 73328d7dd31..812bb5628e1 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilnoise.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilnoise.c
@@ -31,6 +31,8 @@
 #include "BLI_math_vector.h"
 #include "BLI_rand.h"
 
+#include "BLT_translation.h"
+
 #include "MEM_guardedalloc.h"
 
 #include "DNA_gpencil_modifier_types.h"
@@ -38,8 +40,10 @@
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_colortools.h"
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_geom.h"
@@ -47,11 +51,18 @@
 #include "BKE_lib_query.h"
 #include "BKE_modifier.h"
 #include "BKE_object.h"
+#include "BKE_screen.h"
 
 #include "DEG_depsgraph.h"
 #include "DEG_depsgraph_query.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -269,6 +280,72 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  col = uiLayoutColumn(layout, false);
+  uiItemR(col, &ptr, "factor", 0, IFACE_("Position"), ICON_NONE);
+  uiItemR(col, &ptr, "factor_strength", 0, IFACE_("Strength"), ICON_NONE);
+  uiItemR(col, &ptr, "factor_thickness", 0, IFACE_("Thickness"), ICON_NONE);
+  uiItemR(col, &ptr, "factor_uvs", 0, IFACE_("UV"), ICON_NONE);
+  uiItemR(col, &ptr, "noise_scale", 0, NULL, ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void random_header_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiItemR(layout, &ptr, "random", 0, IFACE_("Randomize"), ICON_NONE);
+}
+
+static void random_panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiLayoutSetActive(layout, RNA_boolean_get(&ptr, "random"));
+
+  uiItemR(layout, &ptr, "step", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "seed", 0, NULL, ICON_NONE);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Noise, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "randomize", "", random_header_draw, random_panel_draw, panel_type);
+  PanelType *mask_panel_type = gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(region_type,
+                                     "curve",
+                                     "",
+                                     gpencil_modifier_curve_header_draw,
+                                     gpencil_modifier_curve_panel_draw,
+                                     mask_panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Noise = {
     /* name */ "Noise",
     /* structName */ "NoiseGpencilModifierData",
@@ -291,4 +368,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Noise = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpenciloffset.c b/source/blender/gpencil_modifiers/intern/MOD_gpenciloffset.c
index 686f589ffe9..9cc3712e8f4 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpenciloffset.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpenciloffset.c
@@ -28,22 +28,33 @@
 
 #include "BLI_math.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_colortools.h"
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_gpencil_modifier.h"
 #include "BKE_lib_query.h"
 #include "BKE_modifier.h"
+#include "BKE_screen.h"
 
 #include "DEG_depsgraph.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -136,6 +147,35 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "location", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "rotation", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "scale", 0, NULL, ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, true);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Offset, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Offset = {
     /* name */ "Offset",
     /* structName */ "OffsetGpencilModifierData",
@@ -158,4 +198,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Offset = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilopacity.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilopacity.c
index 92b2621d211..34142709c18 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilopacity.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilopacity.c
@@ -28,13 +28,17 @@
 #include "BLI_blenlib.h"
 #include "BLI_math_vector.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_colortools.h"
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_modifier.h"
@@ -42,10 +46,17 @@
 #include "BKE_main.h"
 #include "BKE_material.h"
 #include "BKE_modifier.h"
+#include "BKE_screen.h"
 
 #include "DEG_depsgraph.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -180,6 +191,7 @@ static void bakeModifier(Main *UNUSED(bmain),
     }
   }
 }
+
 static void freeData(GpencilModifierData *md)
 {
   OpacityGpencilModifierData *gpmd = (OpacityGpencilModifierData *)md;
@@ -196,6 +208,79 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  int modify_color = RNA_enum_get(&ptr, "modify_color");
+
+  uiItemR(layout, &ptr, "modify_color", 0, NULL, ICON_NONE);
+
+  if (modify_color == GP_MODIFY_COLOR_HARDNESS) {
+    uiItemR(layout, &ptr, "hardness", 0, NULL, ICON_NONE);
+  }
+  else {
+    uiItemR(layout, &ptr, "normalize_opacity", 0, NULL, ICON_NONE);
+    const char *text = (RNA_boolean_get(&ptr, "normalize_opacity")) ? IFACE_("Strength") :
+                                                                      IFACE_("Opacity Factor");
+    uiItemR(layout, &ptr, "hardness", 0, text, ICON_NONE);
+  }
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  int modify_color = RNA_enum_get(&ptr, "modify_color");
+  bool show_vertex = (modify_color != GP_MODIFY_COLOR_HARDNESS);
+
+  gpencil_modifier_masking_panel_draw(C, panel, true, show_vertex);
+}
+
+static void curve_header_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  int modify_color = RNA_enum_get(&ptr, "modify_color");
+  uiLayoutSetActive(layout, modify_color != GP_MODIFY_COLOR_HARDNESS);
+
+  gpencil_modifier_curve_header_draw(C, panel);
+}
+
+static void curve_panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  int modify_color = RNA_enum_get(&ptr, "modify_color");
+  uiLayoutSetActive(layout, modify_color != GP_MODIFY_COLOR_HARDNESS);
+
+  gpencil_modifier_curve_panel_draw(C, panel);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Opacity, panel_draw);
+  PanelType *mask_panel_type = gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(
+      region_type, "curve", "", curve_header_draw, curve_panel_draw, mask_panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Opacity = {
     /* name */ "Opacity",
     /* structName */ "OpacityGpencilModifierData",
@@ -218,4 +303,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Opacity = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilsimplify.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilsimplify.c
index 2cda108682e..8d4556421eb 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilsimplify.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilsimplify.c
@@ -26,20 +26,31 @@
 #include "BLI_listbase.h"
 #include "BLI_utildefines.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 #include "DNA_vec_types.h"
 
+#include "BKE_context.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_gpencil_modifier.h"
 #include "BKE_lib_query.h"
 #include "BKE_modifier.h"
+#include "BKE_screen.h"
 
 #include "DEG_depsgraph.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -131,6 +142,48 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  int mode = RNA_enum_get(&ptr, "mode");
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "mode", 0, NULL, ICON_NONE);
+
+  if (mode == GP_SIMPLIFY_FIXED) {
+    uiItemR(layout, &ptr, "step", 0, NULL, ICON_NONE);
+  }
+  else if (mode == GP_SIMPLIFY_ADAPTIVE) {
+    uiItemR(layout, &ptr, "factor", 0, NULL, ICON_NONE);
+  }
+  else if (mode == GP_SIMPLIFY_SAMPLE) {
+    uiItemR(layout, &ptr, "length", 0, NULL, ICON_NONE);
+  }
+  else if (mode == GP_SIMPLIFY_MERGE) {
+    uiItemR(layout, &ptr, "distance", 0, NULL, ICON_NONE);
+  }
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Simplify, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Simplify = {
     /* name */ "Simplify",
     /* structName */ "SimplifyGpencilModifierData",
@@ -153,4 +206,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Simplify = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilsmooth.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilsmooth.c
index e2e13b736e4..175a6d81b1b 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilsmooth.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilsmooth.c
@@ -26,21 +26,32 @@
 #include "BLI_listbase.h"
 #include "BLI_utildefines.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_colortools.h"
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_gpencil_modifier.h"
 #include "BKE_lib_query.h"
 #include "BKE_modifier.h"
+#include "BKE_screen.h"
 
 #include "DEG_depsgraph.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -174,6 +185,47 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *row;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  row = uiLayoutRow(layout, true);
+  uiItemR(row, &ptr, "use_edit_position", UI_ITEM_R_TOGGLE, IFACE_("Position"), ICON_NONE);
+  uiItemR(row, &ptr, "use_edit_strength", UI_ITEM_R_TOGGLE, IFACE_("Stength"), ICON_NONE);
+  uiItemR(row, &ptr, "use_edit_thickness", UI_ITEM_R_TOGGLE, IFACE_("Thickness"), ICON_NONE);
+  uiItemR(row, &ptr, "use_edit_uv", UI_ITEM_R_TOGGLE, IFACE_("UV"), ICON_NONE);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "factor", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "step", 0, IFACE_("Repeat"), ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, true);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Smooth, panel_draw);
+  PanelType *mask_panel_type = gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(region_type,
+                                     "curve",
+                                     "",
+                                     gpencil_modifier_curve_header_draw,
+                                     gpencil_modifier_curve_panel_draw,
+                                     mask_panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Smooth = {
     /* name */ "Smooth",
     /* structName */ "SmoothGpencilModifierData",
@@ -196,4 +248,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Smooth = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilsubdiv.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilsubdiv.c
index 072159136ce..2797235c002 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilsubdiv.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilsubdiv.c
@@ -28,20 +28,31 @@
 #include "BLI_listbase.h"
 #include "BLI_utildefines.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
+#include "BKE_context.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_gpencil_modifier.h"
 #include "BKE_lib_query.h"
 #include "BKE_modifier.h"
+#include "BKE_screen.h"
 
 #include "DEG_depsgraph.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -112,6 +123,34 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "subdivision_type", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "level", 0, IFACE_("Subdivisions"), ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Subdiv, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Subdiv = {
     /* name */ "Subdivide",
     /* structName */ "SubdivGpencilModifierData",
@@ -134,4 +173,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Subdiv = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpenciltexture.c b/source/blender/gpencil_modifiers/intern/MOD_gpenciltexture.c
index a5adf12b617..2d16b6ead5c 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpenciltexture.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpenciltexture.c
@@ -27,23 +27,34 @@
 #include "BLI_math.h"
 #include "BLI_utildefines.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_colortools.h"
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_geom.h"
 #include "BKE_gpencil_modifier.h"
 #include "BKE_lib_query.h"
 #include "BKE_modifier.h"
+#include "BKE_screen.h"
 
 #include "DEG_depsgraph.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -147,8 +158,56 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  int mode = RNA_enum_get(&ptr, "mode");
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "mode", 0, NULL, ICON_NONE);
+
+  if (ELEM(mode, STROKE, STROKE_AND_FILL)) {
+    col = uiLayoutColumn(layout, false);
+    uiItemR(col, &ptr, "fit_method", 0, IFACE_("Stroke Fit Method"), ICON_NONE);
+    uiItemR(col, &ptr, "uv_offset", 0, NULL, ICON_NONE);
+    uiItemR(col, &ptr, "uv_scale", 0, IFACE_("Scale"), ICON_NONE);
+  }
+
+  if (mode == STROKE_AND_FILL) {
+    uiItemS(layout);
+  }
+
+  if (ELEM(mode, FILL, STROKE_AND_FILL)) {
+    col = uiLayoutColumn(layout, false);
+    uiItemR(col, &ptr, "fill_rotation", 0, NULL, ICON_NONE);
+    uiItemR(col, &ptr, "fill_offset", 0, IFACE_("Offset"), ICON_NONE);
+    uiItemR(col, &ptr, "fill_scale", 0, IFACE_("Scale"), ICON_NONE);
+  }
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, true);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Texture, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Texture = {
-    /* name */ "Texture Mapping",
+    /* name */ "TextureMapping",
     /* structName */ "TextureGpencilModifierData",
     /* structSize */ sizeof(TextureGpencilModifierData),
     /* type */ eGpencilModifierTypeType_Gpencil,
@@ -169,4 +228,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Texture = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilthick.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilthick.c
index b9fadea7fd0..4fa47a592ba 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilthick.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilthick.c
@@ -27,22 +27,33 @@
 #include "BLI_math.h"
 #include "BLI_utildefines.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_colortools.h"
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_modifier.h"
 #include "BKE_lib_query.h"
 #include "BKE_modifier.h"
+#include "BKE_screen.h"
 
 #include "DEG_depsgraph.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -166,6 +177,46 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "normalize_thickness", 0, NULL, ICON_NONE);
+
+  if (RNA_boolean_get(&ptr, "normalize_thickness")) {
+    uiItemR(layout, &ptr, "thickness", 0, NULL, ICON_NONE);
+  }
+  else {
+    uiItemR(layout, &ptr, "thickness_factor", 0, NULL, ICON_NONE);
+  }
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, true);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Thick, panel_draw);
+  PanelType *mask_panel_type = gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(region_type,
+                                     "curve",
+                                     "",
+                                     gpencil_modifier_curve_header_draw,
+                                     gpencil_modifier_curve_panel_draw,
+                                     mask_panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Thick = {
     /* name */ "Thickness",
     /* structName */ "ThickGpencilModifierData",
@@ -188,4 +239,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Thick = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpenciltime.c b/source/blender/gpencil_modifiers/intern/MOD_gpenciltime.c
index 85400b56cad..49396f56d26 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpenciltime.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpenciltime.c
@@ -26,20 +26,31 @@
 
 #include "BLI_utildefines.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_colortools.h"
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_modifier.h"
+#include "BKE_screen.h"
 
 #include "DEG_depsgraph.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 static void initData(GpencilModifierData *md)
@@ -165,8 +176,91 @@ static int remapTime(struct GpencilModifierData *md,
   return cfra + offset;
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *row, *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  int mode = RNA_enum_get(&ptr, "mode");
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "mode", 0, NULL, ICON_NONE);
+
+  col = uiLayoutColumn(layout, false);
+
+  const char *text = (mode == GP_TIME_MODE_FIX) ? IFACE_("Frame") : IFACE_("Frame Offset");
+  uiItemR(col, &ptr, "offset", 0, text, ICON_NONE);
+
+  row = uiLayoutRow(col, false);
+  uiLayoutSetActive(row, mode != GP_TIME_MODE_FIX);
+  uiItemR(row, &ptr, "frame_scale", 0, IFACE_("Scale"), ICON_NONE);
+
+  row = uiLayoutRow(layout, false);
+  uiLayoutSetActive(row, mode != GP_TIME_MODE_FIX);
+  uiItemR(row, &ptr, "use_keep_loop", 0, NULL, ICON_NONE);
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void custom_range_header_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  int mode = RNA_enum_get(&ptr, "mode");
+
+  uiLayoutSetActive(layout, mode != GP_TIME_MODE_FIX);
+
+  uiItemR(layout, &ptr, "use_custom_frame_range", 0, NULL, ICON_NONE);
+}
+
+static void custom_range_panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  int mode = RNA_enum_get(&ptr, "mode");
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiLayoutSetActive(
+      layout, (mode != GP_TIME_MODE_FIX) && (RNA_boolean_get(&ptr, "use_custom_frame_range")));
+
+  col = uiLayoutColumn(layout, false);
+  uiItemR(col, &ptr, "frame_start", 0, IFACE_("Frame Start"), ICON_NONE);
+  uiItemR(col, &ptr, "frame_end", 0, IFACE_("End"), ICON_NONE);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, false, false);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Time, panel_draw);
+  gpencil_modifier_subpanel_register(region_type,
+                                     "custom_range",
+                                     "",
+                                     custom_range_header_draw,
+                                     custom_range_panel_draw,
+                                     panel_type);
+  gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Time = {
-    /* name */ "Time Offset",
+    /* name */ "TimeOffset",
     /* structName */ "TimeGpencilModifierData",
     /* structSize */ sizeof(TimeGpencilModifierData),
     /* type */ eGpencilModifierTypeType_Gpencil,
@@ -187,4 +281,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Time = {
     /* foreachObjectLink */ NULL,
     /* foreachIDLink */ NULL,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpenciltint.c b/source/blender/gpencil_modifiers/intern/MOD_gpenciltint.c
index c35728bc8b3..da7d33839f1 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpenciltint.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpenciltint.c
@@ -28,16 +28,20 @@
 #include "BLI_listbase.h"
 #include "BLI_math.h"
 
+#include "BLT_translation.h"
+
 #include "DNA_gpencil_modifier_types.h"
 #include "DNA_gpencil_types.h"
 #include "DNA_meshdata_types.h"
 #include "DNA_modifier_types.h"
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
+#include "DNA_screen_types.h"
 
 #include "BKE_action.h"
 #include "BKE_colorband.h"
 #include "BKE_colortools.h"
+#include "BKE_context.h"
 #include "BKE_deform.h"
 #include "BKE_gpencil.h"
 #include "BKE_gpencil_modifier.h"
@@ -47,10 +51,17 @@
 #include "BKE_material.h"
 #include "BKE_modifier.h"
 #include "BKE_scene.h"
+#include "BKE_screen.h"
 
 #include "MEM_guardedalloc.h"
 
+#include "UI_interface.h"
+#include "UI_resources.h"
+
+#include "RNA_access.h"
+
 #include "MOD_gpencil_modifiertypes.h"
+#include "MOD_gpencil_ui_common.h"
 #include "MOD_gpencil_util.h"
 
 #include "DEG_depsgraph.h"
@@ -330,6 +341,56 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   foreachObjectLink(md, ob, (ObjectWalkFunc)walk, userData);
 }
 
+static void panel_draw(const bContext *C, Panel *panel)
+{
+  uiLayout *col;
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ptr;
+  gpencil_modifier_panel_get_property_pointers(C, panel, NULL, &ptr);
+
+  int tint_type = RNA_enum_get(&ptr, "tint_type");
+
+  uiLayoutSetPropSep(layout, true);
+
+  uiItemR(layout, &ptr, "vertex_mode", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "factor", 0, NULL, ICON_NONE);
+  uiItemR(layout, &ptr, "tint_type", UI_ITEM_R_EXPAND, NULL, ICON_NONE);
+
+  if (tint_type == GP_TINT_UNIFORM) {
+    uiItemR(layout, &ptr, "color", 0, NULL, ICON_NONE);
+  }
+  else {
+    col = uiLayoutColumn(layout, false);
+    uiLayoutSetPropSep(col, false);
+    uiTemplateColorRamp(col, &ptr, "colors", true);
+    uiItemS(layout);
+    uiItemR(layout, &ptr, "object", 0, NULL, ICON_NONE);
+    uiItemR(layout, &ptr, "radius", 0, NULL, ICON_NONE);
+  }
+
+  gpencil_modifier_panel_end(layout, &ptr);
+}
+
+static void mask_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_masking_panel_draw(C, panel, true, true);
+}
+
+static void panelRegister(ARegionType *region_type)
+{
+  PanelType *panel_type = gpencil_modifier_panel_register(
+      region_type, eGpencilModifierType_Tint, panel_draw);
+  PanelType *mask_panel_type = gpencil_modifier_subpanel_register(
+      region_type, "mask", "Influence", NULL, mask_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(region_type,
+                                     "curve",
+                                     "",
+                                     gpencil_modifier_curve_header_draw,
+                                     gpencil_modifier_curve_panel_draw,
+                                     mask_panel_type);
+}
+
 GpencilModifierTypeInfo modifierType_Gpencil_Tint = {
     /* name */ "Tint",
     /* structName */ "TintGpencilModifierData",
@@ -352,4 +413,5 @@ GpencilModifierTypeInfo modifierType_Gpencil_Tint = {
     /* foreachObjectLink */ foreachObjectLink,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,
+    /* panelRegister */ panelRegister,
 };
diff --git a/source/blender/makesdna/DNA_gpencil_modifier_types.h b/source/blender/makesdna/DNA_gpencil_modifier_types.h
index 674999ab465..5d35db1a960 100644
--- a/source/blender/makesdna/DNA_gpencil_modifier_types.h
+++ b/source/blender/makesdna/DNA_gpencil_modifier_types.h
@@ -58,7 +58,7 @@ typedef enum GpencilModifierMode {
   eGpencilModifierMode_Realtime = (1 << 0),
   eGpencilModifierMode_Render = (1 << 1),
   eGpencilModifierMode_Editmode = (1 << 2),
-  eGpencilModifierMode_Expanded = (1 << 3),
+  eGpencilModifierMode_Expanded_DEPRECATED = (1 << 3),
 } GpencilModifierMode;
 
 typedef enum {
@@ -72,7 +72,7 @@ typedef struct GpencilModifierData {
   int type, mode;
   int stackindex;
   short flag;
-  short _pad;
+  short ui_expand_flag;
   /** MAX_NAME. */
   char name[64];
 
diff --git a/source/blender/makesrna/intern/rna_gpencil_modifier.c b/source/blender/makesrna/intern/rna_gpencil_modifier.c
index 3a8ded1a275..06bec3bf944 100644
--- a/source/blender/makesrna/intern/rna_gpencil_modifier.c
+++ b/source/blender/makesrna/intern/rna_gpencil_modifier.c
@@ -1490,7 +1490,7 @@ static void rna_def_modifier_gpencilarray(BlenderRNA *brna)
   RNA_def_property_ui_range(prop, -FLT_MAX, FLT_MAX, 1, RNA_TRANSLATION_PREC_DEFAULT);
   RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
 
-  prop = RNA_def_property(srna, "relative_offset", PROP_FLOAT, PROP_NONE);
+  prop = RNA_def_property(srna, "relative_offset", PROP_FLOAT, PROP_XYZ);
   RNA_def_property_float_sdna(prop, NULL, "shift");
   RNA_def_property_ui_text(
       prop,
@@ -2127,8 +2127,7 @@ static void rna_def_modifier_gpencilmultiply(BlenderRNA *brna)
 
   prop = RNA_def_property(srna, "use_fade", PROP_BOOLEAN, PROP_NONE);
   RNA_def_property_boolean_sdna(prop, NULL, "flags", GP_MULTIPLY_ENABLE_FADING);
-  RNA_def_property_ui_text(
-      prop, "Enable Fade", "Fade the stroke thickness for each generated stroke");
+  RNA_def_property_ui_text(prop, "Fade", "Fade the stroke thickness for each generated stroke");
   RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
 
   prop = RNA_def_property(srna, "split_angle", PROP_FLOAT, PROP_ANGLE);
@@ -2183,12 +2182,12 @@ static void rna_def_modifier_gpenciltexture(BlenderRNA *brna)
       {GP_TEX_CONSTANT_LENGTH,
        "CONSTANT_LENGTH",
        0,
-       "Keep Texture at Constant Length",
+       "Constant Length",
        "Keep the texture at a constant length regardless of the length of each stroke"},
       {GP_TEX_FIT_STROKE,
        "FIT_STROKE",
        0,
-       "Fit Texture to Stroke Length",
+       "Stroke Length",
        "Scale the texture to fit the length of each stroke"},
       {0, NULL, 0, NULL, NULL},
   };
@@ -2269,7 +2268,7 @@ static void rna_def_modifier_gpenciltexture(BlenderRNA *brna)
   RNA_def_property_range(prop, -FLT_MAX, FLT_MAX);
   RNA_def_property_ui_range(prop, -100.0, 100.0, 0.1, 3);
   RNA_def_property_float_default(prop, 0.0f);
-  RNA_def_property_ui_text(prop, "Offset UVs", "Offset value to add to stroke UVs");
+  RNA_def_property_ui_text(prop, "UV Offset", "Offset value to add to stroke UVs");
   RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
 
   prop = RNA_def_property(srna, "uv_scale", PROP_FLOAT, PROP_NONE);
@@ -2360,7 +2359,7 @@ void RNA_def_greasepencil_modifier(BlenderRNA *brna)
 
   prop = RNA_def_property(srna, "show_expanded", PROP_BOOLEAN, PROP_NONE);
   RNA_def_property_flag(prop, PROP_NO_DEG_UPDATE);
-  RNA_def_property_boolean_sdna(prop, NULL, "mode", eGpencilModifierMode_Expanded);
+  RNA_def_property_boolean_sdna(prop, NULL, "ui_expand_flag", 0);
   RNA_def_property_override_flag(prop, PROPOVERRIDE_OVERRIDABLE_LIBRARY);
   RNA_def_property_ui_text(prop, "Expanded", "Set modifier expanded in the user interface");
   RNA_def_property_ui_icon(prop, ICON_DISCLOSURE_TRI_RIGHT, 1);
diff --git a/source/blender/makesrna/intern/rna_ui_api.c b/source/blender/makesrna/intern/rna_ui_api.c
index 8bfee4cc26c..974daa51f99 100644
--- a/source/blender/makesrna/intern/rna_ui_api.c
+++ b/source/blender/makesrna/intern/rna_ui_api.c
@@ -1222,13 +1222,10 @@ void RNA_api_ui_layout(StructRNA *srna)
                   "",
                   "Add panels for bone constraints instead of object constraints");
 
-  func = RNA_def_function(srna, "template_greasepencil_modifier", "uiTemplateGpencilModifier");
+  func = RNA_def_function(srna, "template_grease_pencil_modifiers", "uiTemplateGpencilModifiers");
   RNA_def_function_flag(func, FUNC_USE_CONTEXT);
-  RNA_def_function_ui_description(func, "Generates the UI layout for grease pencil modifiers");
-  parm = RNA_def_pointer(func, "data", "GpencilModifier", "", "Modifier data");
-  RNA_def_parameter_flags(parm, PROP_NEVER_NULL, PARM_REQUIRED | PARM_RNAPTR);
-  parm = RNA_def_pointer(func, "layout", "UILayout", "", "Sub-layout to put items in");
-  RNA_def_function_return(func, parm);
+  RNA_def_function_ui_description(func,
+                                  "Generates the panels for the grease pencil modifier stack");
 
   func = RNA_def_function(srna, "template_shaderfx", "uiTemplateShaderFx");
   RNA_def_function_flag(func, FUNC_USE_CONTEXT);