Modifier: add support for vertex groups

Allow blending the imported cache with the modifiers stack above the
MeshCache modifier.

This is particularly useful for instance when dealing with cloth
simulations performed in another software, where some parts of the cloth
are completely pinned (non-simulated, following the armature). Indeed,
this would allow modifying the animation in some areas without having to
rebake the other parts or the cloth, resulting in a much more flexible
workflow.

Reviewed By: #modeling, campbellbarton, mont29

Ref D9898

1 files changed, 15 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_modifier.c b/source/blender/makesrna/intern/rna_modifier.c
index f11d845c582..fb4fd4528d6 100644
--- a/source/blender/makesrna/intern/rna_modifier.c
+++ b/source/blender/makesrna/intern/rna_modifier.c
@@ -755,6 +755,7 @@ RNA_MOD_VGROUP_NAME_SET(LaplacianDeform, anchor_grp_name);
 RNA_MOD_VGROUP_NAME_SET(LaplacianSmooth, defgrp_name);
 RNA_MOD_VGROUP_NAME_SET(Lattice, name);
 RNA_MOD_VGROUP_NAME_SET(Mask, vgroup);
+RNA_MOD_VGROUP_NAME_SET(MeshCache, defgrp_name);
 RNA_MOD_VGROUP_NAME_SET(MeshDeform, defgrp_name);
 RNA_MOD_VGROUP_NAME_SET(NormalEdit, defgrp_name);
 RNA_MOD_VGROUP_NAME_SET(Shrinkwrap, vgroup_name);
@@ -6045,6 +6046,20 @@ static void rna_def_modifier_meshcache(BlenderRNA *brna)
   RNA_def_property_ui_text(prop, "Influence", "Influence of the deformation");
   RNA_def_property_update(prop, 0, "rna_Modifier_update");
 
+  prop = RNA_def_property(srna, "vertex_group", PROP_STRING, PROP_NONE);
+  RNA_def_property_string_sdna(prop, NULL, "defgrp_name");
+  RNA_def_property_ui_text(
+      prop,
+      "Vertex Group",
+      "Name of the Vertex Group which determines the influence of the modifier per point");
+  RNA_def_property_string_funcs(prop, NULL, NULL, "rna_MeshCacheModifier_defgrp_name_set");
+  RNA_def_property_update(prop, 0, "rna_Modifier_update");
+
+  prop = RNA_def_property(srna, "invert_vertex_group", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flag", MOD_MESHCACHE_INVERT_VERTEX_GROUP);
+  RNA_def_property_ui_text(prop, "Invert", "Invert vertex group influence");
+  RNA_def_property_update(prop, 0, "rna_Modifier_update");
+
   /* -------------------------------------------------------------------- */
   /* Axis Conversion */
   prop = RNA_def_property(srna, "forward_axis", PROP_ENUM, PROP_NONE);