1 files changed, 60 insertions, 1 deletions

diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencilthick.c b/source/blender/gpencil_modifiers/intern/MOD_gpencilthick.c
index a13f8d64755..126949cd659 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencilthick.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencilthick.c
@@ -43,6 +43,8 @@
 #include "BKE_screen.h"
 
 #include "DEG_depsgraph.h"
+#include "DEG_depsgraph_build.h"
+#include "DEG_depsgraph_query.h"
 
 #include "UI_interface.h"
 #include "UI_resources.h"
@@ -128,6 +130,30 @@ static void deformStroke(GpencilModifierData *md,
     }
 
     float curvef = 1.0f;
+
+    float factor_depth = 1.0f;
+
+    if (mmd->flag & GP_THICK_FADING) {
+      if (mmd->object) {
+        float gvert[3];
+        mul_v3_m4v3(gvert, ob->obmat, &pt->x);
+        float dist = len_v3v3(mmd->object->obmat[3], gvert);
+        float fading_max = MAX2(mmd->fading_start, mmd->fading_end);
+        float fading_min = MIN2(mmd->fading_start, mmd->fading_end);
+
+        /* Better with ratiof() function from line art. */
+        if (dist > fading_max) {
+          factor_depth = 0.0f;
+        }
+        else if (dist <= fading_max && dist > fading_min) {
+          factor_depth = (fading_max - dist) / (fading_max - fading_min);
+        }
+        else {
+          factor_depth = 1.0f;
+        }
+      }
+    }
+
     if ((mmd->flag & GP_THICK_CUSTOM_CURVE) && (mmd->curve_thickness)) {
       /* Normalize value to evaluate curve. */
       float value = (float)i / (gps->totpoints - 1);
@@ -144,6 +170,11 @@ static void deformStroke(GpencilModifierData *md,
       weight *= curvef;
     }
 
+    /* Apply distance fading. */
+    if (mmd->flag & GP_THICK_FADING) {
+      target = interpf(target, mmd->fading_end_factor, factor_depth);
+    }
+
     pt->pressure = interpf(target, pt->pressure, weight);
 
     CLAMP_MIN(pt->pressure, 0.0f);
@@ -171,6 +202,32 @@ static void foreachIDLink(GpencilModifierData *md, Object *ob, IDWalkFunc walk,
   ThickGpencilModifierData *mmd = (ThickGpencilModifierData *)md;
 
   walk(userData, ob, (ID **)&mmd->material, IDWALK_CB_USER);
+  walk(userData, ob, (ID **)&mmd->object, IDWALK_CB_NOP);
+}
+
+static void updateDepsgraph(GpencilModifierData *md,
+                            const ModifierUpdateDepsgraphContext *ctx,
+                            const int UNUSED(mode))
+{
+  ThickGpencilModifierData *mmd = (ThickGpencilModifierData *)md;
+  if (mmd->object != NULL) {
+    DEG_add_object_relation(ctx->node, mmd->object, DEG_OB_COMP_TRANSFORM, "Thickness Modifier");
+  }
+  DEG_add_object_relation(ctx->node, ctx->object, DEG_OB_COMP_TRANSFORM, "Thickness Modifier");
+}
+
+static void fading_header_draw(const bContext *UNUSED(C), Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA *ptr = gpencil_modifier_panel_get_property_pointers(panel, NULL);
+
+  uiItemR(layout, ptr, "use_fading", 0, NULL, ICON_NONE);
+}
+
+static void fading_panel_draw(const bContext *C, Panel *panel)
+{
+  gpencil_modifier_fading_draw(C, panel);
 }
 
 static void panel_draw(const bContext *UNUSED(C), Panel *panel)
@@ -202,6 +259,8 @@ static void panelRegister(ARegionType *region_type)
 {
   PanelType *panel_type = gpencil_modifier_panel_register(
       region_type, eGpencilModifierType_Thick, panel_draw);
+  gpencil_modifier_subpanel_register(
+      region_type, "fading", "", fading_header_draw, fading_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,
@@ -229,7 +288,7 @@ GpencilModifierTypeInfo modifierType_Gpencil_Thick = {
     /* initData */ initData,
     /* freeData */ freeData,
     /* isDisabled */ NULL,
-    /* updateDepsgraph */ NULL,
+    /* updateDepsgraph */ updateDepsgraph,
     /* dependsOnTime */ NULL,
     /* foreachIDLink */ foreachIDLink,
     /* foreachTexLink */ NULL,