Multires: Properly support virtual modifiers for Apply Base

The initial code from earlier from today didn't really work reliable
since it is not possible to apply virtual modifiers but not the real
multires one (in a situation like mesh with shapekeys and multires).

New code uses less memory and has better performance for the case
when there are actual modifiers leading the multires. The case when
there is only multires will not be as performant as possible at this
moment.

1 files changed, 7 insertions, 12 deletions

diff --git a/source/blender/blenkernel/intern/multires_reshape_apply_base.c b/source/blender/blenkernel/intern/multires_reshape_apply_base.c
index 958fb60bbdc..62418150ff1 100644
--- a/source/blender/blenkernel/intern/multires_reshape_apply_base.c
+++ b/source/blender/blenkernel/intern/multires_reshape_apply_base.c
@@ -189,16 +189,11 @@ void multires_reshape_apply_base_refine_from_deform(MultiresReshapeContext *resh
   BLI_assert(object != NULL);
   BLI_assert(mmd != NULL);
 
-  /* If there are no modifiers prior to the multires can use base mesh as it have all the updated
-   * vertices already. */
-  if (mmd->modifier.prev == NULL) {
-    BKE_subdiv_eval_update_from_mesh(reshape_context->subdiv, reshape_context->base_mesh, NULL);
-  }
-  else {
-    /* TODO(sergey): Possible optimization is to only evaluate new verticies positions without
-     * construction of the entire mesh. */
-    Mesh *deformed_base_mesh = BKE_multires_create_deformed_base_mesh(depsgraph, object, mmd);
-    BKE_subdiv_eval_update_from_mesh(reshape_context->subdiv, deformed_base_mesh, NULL);
-    BKE_id_free(NULL, deformed_base_mesh);
-  }
+  float(*deformed_verts)[3] = BKE_multires_create_deformed_base_mesh_vert_coords(
+      depsgraph, object, mmd, NULL);
+
+  BKE_subdiv_eval_update_from_mesh(
+      reshape_context->subdiv, reshape_context->base_mesh, deformed_verts);
+
+  MEM_freeN(deformed_verts);
 }