New object API function : BKE_object_eval_reset()

This restores the object->data to a non-modifier evaluated state.

So this allow us to change evaluated object modifier stack directly and
get BKE_mesh_new_from_object() for the evalauted object.

source/blender/blenkernel/BKE_object.h

@@ -221,6 +221,10 @@ void BKE_object_tfm_protected_restore(
         const ObjectTfmProtectedChannels *obtfm,
         const short protectflag);
 
+
+void BKE_object_eval_reset(
+        struct Object *ob_eval);
+
 /* Dependency graph evaluation callbacks. */
 void BKE_object_eval_local_transform(
         struct Depsgraph *depsgraph,

source/blender/blenkernel/intern/object_update.c

@@ -69,6 +69,18 @@
 #include "DEG_depsgraph.h"
 #include "DEG_depsgraph_query.h"
 
+/**
+ * Restore the object->data to a non-modifier evaluated state.
+ *
+ * Some changes done directly in evaluated object require them to be reset
+ * before being re-evaluated.
+ * For example, we need to call this before BKE_mesh_new_from_object(),
+ * in case we removed/added modifiers in the evaluated object.
+ **/
+void BKE_object_eval_reset(Object *ob_eval)
+{
+	BKE_object_free_derived_caches(ob_eval);
+}
 
 void BKE_object_eval_local_transform(Depsgraph *depsgraph, Object *ob)
 {

source/blender/editors/object/object_bake_api.c

@@ -844,8 +844,7 @@ static int bake(
 				md = md_next;
 			}
 
-			/* We need to restore object->data to a non-modifier-evaluated state. */
-			BKE_object_free_derived_caches(ob_low_eval);
+			BKE_object_eval_reset(ob_low_eval);
 			me_cage = bake_mesh_new_from_object(depsgraph, bmain, scene, ob_low_eval);
 			RE_bake_pixels_populate(me_cage, pixel_array_low, num_pixels, &bake_images, uv_layer);
 		}