Fix T94479: GPU Subdivision surface modifier does not apply to Cycles renders

Since now we delegate the evaluation of the last subsurf modifier in the stack
to the draw code, Cycles does not get a subdivided mesh anymore. This is because
the subdivision wrapper for generating a CPU side subdivision is never created
as it is only ever created via `BKE_object_get_evaluated_mesh` which Cycles does
not call (rather, it accesses the Mesh either via `object.data()`, or via
`object.to_mesh()`).

This ensures that a subdivision wrapper is created when accessing the object data
or converting an Object to a Mesh via the RNA/Python API.

Reviewed by: brecht

Differential Revision: https://developer.blender.org/D14048

2 files changed, 24 insertions, 3 deletions

diff --git a/source/blender/blenkernel/intern/mesh_convert.cc b/source/blender/blenkernel/intern/mesh_convert.cc
index 7d5f156040d..f8deb4e6807 100644
--- a/source/blender/blenkernel/intern/mesh_convert.cc
+++ b/source/blender/blenkernel/intern/mesh_convert.cc
@@ -1051,7 +1051,12 @@ static Mesh *mesh_new_from_mesh(Object *object, Mesh *mesh)
 {
   /* While we could copy this into the new mesh,
    * add the data to 'mesh' so future calls to this function don't need to re-convert the data. */
-  BKE_mesh_wrapper_ensure_mdata(mesh);
+  if (mesh->runtime.wrapper_type == ME_WRAPPER_TYPE_BMESH) {
+    BKE_mesh_wrapper_ensure_mdata(mesh);
+  }
+  else {
+    BKE_mesh_wrapper_ensure_subdivision(object, mesh);
+  }
 
   Mesh *mesh_result = (Mesh *)BKE_id_copy_ex(
       nullptr, &mesh->id, nullptr, LIB_ID_CREATE_NO_MAIN | LIB_ID_CREATE_NO_USER_REFCOUNT);
@@ -1088,6 +1093,7 @@ static Mesh *mesh_new_from_mesh_object_with_layers(Depsgraph *depsgraph,
     mask.pmask |= CD_MASK_ORIGINDEX;
   }
   Mesh *result = mesh_create_eval_final(depsgraph, scene, &object_for_eval, &mask);
+  BKE_mesh_wrapper_ensure_subdivision(object, result);
   return result;
 }
 
diff --git a/source/blender/makesrna/intern/rna_object.c b/source/blender/makesrna/intern/rna_object.c
index a098693459b..207cde4b866 100644
--- a/source/blender/makesrna/intern/rna_object.c
+++ b/source/blender/makesrna/intern/rna_object.c
@@ -345,6 +345,7 @@ const EnumPropertyItem rna_enum_object_axis_items[] = {
 #  include "BKE_key.h"
 #  include "BKE_material.h"
 #  include "BKE_mesh.h"
+#  include "BKE_mesh_wrapper.h"
 #  include "BKE_modifier.h"
 #  include "BKE_object.h"
 #  include "BKE_particle.h"
@@ -524,6 +525,17 @@ void rna_Object_data_update(Main *bmain, Scene *scene, PointerRNA *ptr)
   rna_Object_internal_update_data_dependency(bmain, scene, ptr);
 }
 
+static PointerRNA rna_Object_data_get(PointerRNA *ptr)
+{
+  Object *ob = (Object *)ptr->data;
+  if (ob->type == OB_MESH) {
+    Mesh *me = (Mesh *)ob->data;
+    me = BKE_mesh_wrapper_ensure_subdivision(ob, me);
+    return rna_pointer_inherit_refine(ptr, &RNA_Mesh, me);
+  }
+  return rna_pointer_inherit_refine(ptr, &RNA_ID, ob->data);
+}
+
 static void rna_Object_data_set(PointerRNA *ptr, PointerRNA value, struct ReportList *reports)
 {
   Object *ob = (Object *)ptr->data;
@@ -3055,8 +3067,11 @@ static void rna_def_object(BlenderRNA *brna)
 
   prop = RNA_def_property(srna, "data", PROP_POINTER, PROP_NONE);
   RNA_def_property_struct_type(prop, "ID");
-  RNA_def_property_pointer_funcs(
-      prop, NULL, "rna_Object_data_set", "rna_Object_data_typef", "rna_Object_data_poll");
+  RNA_def_property_pointer_funcs(prop,
+                                 "rna_Object_data_get",
+                                 "rna_Object_data_set",
+                                 "rna_Object_data_typef",
+                                 "rna_Object_data_poll");
   RNA_def_property_flag(prop, PROP_EDITABLE | PROP_NEVER_UNLINK);
   RNA_def_property_ui_text(prop, "Data", "Object data");
   RNA_def_property_update(prop, 0, "rna_Object_data_update");