Warp modifier: add bone from and bone to options when using armature objects

This commit adds the option to use armature bones for the From and To targets
when using armature objects.

The changes are based on the UV Warp modifier.

Reviewed By: mont29

Differential Revision: https://developer.blender.org/D6820

4 files changed, 70 insertions, 10 deletions

diff --git a/release/scripts/startup/bl_ui/properties_data_modifier.py b/release/scripts/startup/bl_ui/properties_data_modifier.py
index e72e826ce23..1f7c5bfd054 100644
--- a/release/scripts/startup/bl_ui/properties_data_modifier.py
+++ b/release/scripts/startup/bl_ui/properties_data_modifier.py
@@ -1173,11 +1173,27 @@ class DATA_PT_modifiers(ModifierButtonsPanel, Panel):
         col.label(text="From:")
         col.prop(md, "object_from", text="")
 
-        col.prop(md, "use_volume_preserve")
-
         col = split.column()
         col.label(text="To:")
         col.prop(md, "object_to", text="")
+
+        split = layout.split()
+        col = split.column()
+        obj = md.object_from
+        if obj and obj.type == 'ARMATURE':
+            col.label(text="Bone:")
+            col.prop_search(md, "bone_from", obj.data, "bones", text="")
+
+        col = split.column()
+        obj = md.object_to
+        if obj and obj.type == 'ARMATURE':
+            col.label(text="Bone:")
+            col.prop_search(md, "bone_to", obj.data, "bones", text="")
+
+        split = layout.split()
+        col = split.column()
+        col.prop(md, "use_volume_preserve")
+        col = split.column()
         row = col.row(align=True)
         row.prop_search(md, "vertex_group", ob, "vertex_groups", text="")
         row.prop(md, "invert_vertex_group", text="", icon='ARROW_LEFTRIGHT')
diff --git a/source/blender/makesdna/DNA_modifier_types.h b/source/blender/makesdna/DNA_modifier_types.h
index 5213dba6c79..405f12d5fb9 100644
--- a/source/blender/makesdna/DNA_modifier_types.h
+++ b/source/blender/makesdna/DNA_modifier_types.h
@@ -1324,6 +1324,11 @@ typedef struct WarpModifierData {
 
   struct Object *object_from;
   struct Object *object_to;
+  /** Optional name of bone target, MAX_ID_NAME-2. */
+  char bone_from[64];
+  /** Optional name of bone target, MAX_ID_NAME-2. */
+  char bone_to[64];
+
   struct CurveMapping *curfalloff;
   /** Optional vertexgroup name, MAX_VGROUP_NAME. */
   char defgrp_name[64];
diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index e0c9be7ddae..51b50647e1d 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -1795,17 +1795,29 @@ static void rna_def_modifier_warp(BlenderRNA *brna)
   RNA_def_struct_ui_icon(srna, ICON_MOD_WARP);
 
   prop = RNA_def_property(srna, "object_from", PROP_POINTER, PROP_NONE);
-  RNA_def_property_ui_text(prop, "From", "Object to transform from");
+  RNA_def_property_pointer_sdna(prop, NULL, "object_from");
+  RNA_def_property_ui_text(prop, "Object From", "Object to transform from");
   RNA_def_property_flag(prop, PROP_EDITABLE | PROP_ID_SELF_CHECK);
   RNA_def_property_override_flag(prop, PROPOVERRIDE_OVERRIDABLE_LIBRARY);
   RNA_def_property_update(prop, 0, "rna_Modifier_dependency_update");
 
+  prop = RNA_def_property(srna, "bone_from", PROP_STRING, PROP_NONE);
+  RNA_def_property_string_sdna(prop, NULL, "bone_from");
+  RNA_def_property_ui_text(prop, "Bone From", "Bone to transform from");
+  RNA_def_property_update(prop, 0, "rna_Modifier_dependency_update");
+
   prop = RNA_def_property(srna, "object_to", PROP_POINTER, PROP_NONE);
-  RNA_def_property_ui_text(prop, "To", "Object to transform to");
+  RNA_def_property_pointer_sdna(prop, NULL, "object_to");
+  RNA_def_property_ui_text(prop, "Object To", "Object to transform to");
   RNA_def_property_flag(prop, PROP_EDITABLE | PROP_ID_SELF_CHECK);
   RNA_def_property_override_flag(prop, PROPOVERRIDE_OVERRIDABLE_LIBRARY);
   RNA_def_property_update(prop, 0, "rna_Modifier_dependency_update");
 
+  prop = RNA_def_property(srna, "bone_to", PROP_STRING, PROP_NONE);
+  RNA_def_property_string_sdna(prop, NULL, "bone_to");
+  RNA_def_property_ui_text(prop, "Bone To", "Bone defining offset");
+  RNA_def_property_update(prop, 0, "rna_Modifier_dependency_update");
+
   prop = RNA_def_property(srna, "strength", PROP_FLOAT, PROP_NONE);
   RNA_def_property_range(prop, -FLT_MAX, FLT_MAX);
   RNA_def_property_ui_range(prop, -100, 100, 10, 2);
diff --git a/source/blender/modifiers/intern/MOD_warp.c b/source/blender/modifiers/intern/MOD_warp.c
index 4a98afbb91c..3157dddd8fc 100644
--- a/source/blender/modifiers/intern/MOD_warp.c
+++ b/source/blender/modifiers/intern/MOD_warp.c
@@ -32,6 +32,7 @@
 
 #include "BKE_colortools.h"
 #include "BKE_deform.h"
+#include "BKE_action.h" /* BKE_pose_channel_find_name */
 #include "BKE_editmesh.h"
 #include "BKE_lib_id.h"
 #include "BKE_lib_query.h"
@@ -85,6 +86,17 @@ static void requiredDataMask(Object *UNUSED(ob),
   }
 }
 
+static void matrix_from_obj_pchan(float mat[4][4], float obinv[4][4], Object *ob, const char *bonename)
+{
+  bPoseChannel *pchan = BKE_pose_channel_find_name(ob->pose, bonename);
+  if (pchan) {
+    mul_m4_m4m4(mat, obinv, pchan->pose_mat);
+  }
+  else {
+    mul_m4_m4m4(mat, obinv, ob->obmat);
+  }
+}
+
 static bool dependsOnTime(ModifierData *md)
 {
   WarpModifierData *wmd = (WarpModifierData *)md;
@@ -135,15 +147,29 @@ static void foreachTexLink(ModifierData *md, Object *ob, TexWalkFunc walk, void
   walk(userData, ob, md, "texture");
 }
 
+static void warp_deps_object_bone_new(struct DepsNodeHandle *node,
+                                         Object *object,
+                                         const char *bonename)
+{
+  if (bonename[0] && object->type == OB_ARMATURE) {
+    DEG_add_object_relation(node, object, DEG_OB_COMP_EVAL_POSE, "Warp Modifier");
+  }
+  else {
+    DEG_add_object_relation(node, object, DEG_OB_COMP_TRANSFORM, "Warp Modifier");
+  }
+}
+
 static void updateDepsgraph(ModifierData *md, const ModifierUpdateDepsgraphContext *ctx)
 {
   WarpModifierData *wmd = (WarpModifierData *)md;
+
   if (wmd->object_from != NULL && wmd->object_to != NULL) {
-    DEG_add_modifier_to_transform_relation(ctx->node, "Warplace Modifier");
-    DEG_add_object_relation(
-        ctx->node, wmd->object_from, DEG_OB_COMP_TRANSFORM, "Warp Modifier from");
-    DEG_add_object_relation(ctx->node, wmd->object_to, DEG_OB_COMP_TRANSFORM, "Warp Modifier to");
+    warp_deps_object_bone_new(ctx->node, wmd->object_from, wmd->bone_from);
+    warp_deps_object_bone_new(ctx->node, wmd->object_to, wmd->bone_to);
+
+    DEG_add_modifier_to_transform_relation(ctx->node, "Warp Modifier");
   }
+
   if ((wmd->texmapping == MOD_DISP_MAP_OBJECT) && wmd->map_object != NULL) {
     DEG_add_object_relation(
         ctx->node, wmd->map_object, DEG_OB_COMP_TRANSFORM, "Warp Modifier map");
@@ -197,8 +223,9 @@ static void warpModifier_do(WarpModifierData *wmd,
 
   invert_m4_m4(obinv, ob->obmat);
 
-  mul_m4_m4m4(mat_from, obinv, wmd->object_from->obmat);
-  mul_m4_m4m4(mat_to, obinv, wmd->object_to->obmat);
+  /* Checks that the objects/bones are available. */
+  matrix_from_obj_pchan(mat_from, obinv, wmd->object_from, wmd->bone_from);
+  matrix_from_obj_pchan(mat_to, obinv, wmd->object_to, wmd->bone_to);
 
   invert_m4_m4(tmat, mat_from);  // swap?
   mul_m4_m4m4(mat_final, tmat, mat_to);