Fix T81915: Draw Face Sets not working with deformed sculpt mesh

The draw face sets brush uses the poly center when used in meshes to increase
its precision when working in low poly geometry. For this to work with deformed
meshes, the deformed coordinates from the PBVH should be used instead.

Reviewed By: sergey

Maniphest Tasks: T81915

Differential Revision: https://developer.blender.org/D9424

1 files changed, 15 insertions, 0 deletions

diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index 56b5a494df0..875f24837c1 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -292,6 +292,21 @@ void SCULPT_active_vertex_normal_get(SculptSession *ss, float normal[3])
   SCULPT_vertex_normal_get(ss, SCULPT_active_vertex_get(ss), normal);
 }
 
+MVert *SCULPT_mesh_deformed_mverts_get(SculptSession *ss)
+{
+  switch (BKE_pbvh_type(ss->pbvh)) {
+    case PBVH_FACES:
+      if (ss->shapekey_active || ss->deform_modifiers_active) {
+        return BKE_pbvh_get_verts(ss->pbvh);
+      }
+      return ss->mvert;
+    case PBVH_BMESH:
+    case PBVH_GRIDS:
+      return NULL;
+  }
+  return NULL;
+}
+
 float *SCULPT_brush_deform_target_vertex_co_get(SculptSession *ss,
                                                 const int deform_target,
                                                 PBVHVertexIter *iter)