- Save MDISPS layer when applying modifier.

  All sculpting used to disappear before. Save MDISPS if new mesh has got the same faces amount.
  NOTE: maybe some other layers should be saved?
- Apply multires modififier if MDISPS was auto-created.
  Multires's applyModifier used to return unchanged DM when MDISPS was auto-created.
- Set multires totlvl from MDISPS layer when new multires was added to mesh with existing MDISPS layer.

3 files changed, 17 insertions, 1 deletions

diff --git a/source/blender/blenkernel/intern/DerivedMesh.c b/source/blender/blenkernel/intern/DerivedMesh.c
index de7b962e38a..0b3bd106544 100644
--- a/source/blender/blenkernel/intern/DerivedMesh.c
+++ b/source/blender/blenkernel/intern/DerivedMesh.c
@@ -239,6 +239,15 @@ void DM_to_mesh(DerivedMesh *dm, Mesh *me)
 	if(!CustomData_has_layer(&tmp.fdata, CD_MFACE))
 		CustomData_add_layer(&tmp.fdata, CD_MFACE, CD_ASSIGN, dm->dupFaceArray(dm), totface);
 
+	/* object had got displacement layer, should copy this layer to save sculpted data */
+	/* NOTE: maybe some other layers should be copied? nazgul */
+	if(CustomData_has_layer(&me->fdata, CD_MDISPS)) {
+		if (totface == me->totface) {
+			MDisps *mdisps = CustomData_get_layer(&me->fdata, CD_MDISPS);
+			CustomData_add_layer(&tmp.fdata, CD_MDISPS, CD_DUPLICATE, mdisps, totface);
+		}
+	}
+
 	mesh_update_customdata_pointers(&tmp);
 
 	CustomData_free(&me->vdata, me->totvert);
diff --git a/source/blender/editors/object/object_modifier.c b/source/blender/editors/object/object_modifier.c
index 7cf24d5d07d..ec44383f1dd 100644
--- a/source/blender/editors/object/object_modifier.c
+++ b/source/blender/editors/object/object_modifier.c
@@ -132,6 +132,9 @@ ModifierData *ED_object_modifier_add(ReportList *reports, Main *bmain, Scene *sc
 		}
 		else if(type == eModifierType_Surface)
 			DAG_scene_sort(bmain, scene);
+		else if(type == eModifierType_Multires)
+			/* set totlvl from existing MDISPS layer if object already had it */
+			multiresModifier_set_levels_from_disps(new_md, ob);
 	}
 
 	DAG_id_flush_update(&ob->id, OB_RECALC_DATA);
@@ -431,6 +434,11 @@ static int modifier_apply_obdata(ReportList *reports, Scene *scene, Object *ob,
 			DM_to_mesh(dm, me);
 
 			dm->release(dm);
+
+			if(md->type == eModifierType_Multires) {
+				CustomData_external_remove(&me->fdata, &me->id, CD_MDISPS, me->totface);
+				CustomData_free_layer_active(&me->fdata, CD_MDISPS, me->totface);
+			}
 		}
 	} 
 	else if (ELEM(ob->type, OB_CURVE, OB_SURF)) {
diff --git a/source/blender/modifiers/intern/MOD_multires.c b/source/blender/modifiers/intern/MOD_multires.c
index dd99c88a684..988ce3921a7 100644
--- a/source/blender/modifiers/intern/MOD_multires.c
+++ b/source/blender/modifiers/intern/MOD_multires.c
@@ -74,7 +74,6 @@ static DerivedMesh *applyModifier(ModifierData *md, Object *ob, DerivedMesh *dm,
 		if(!CustomData_get_layer(&me->fdata, CD_MDISPS)) {
 			/* multires always needs a displacement layer */
 			CustomData_add_layer(&me->fdata, CD_MDISPS, CD_CALLOC, NULL, me->totface);
-			return dm;
 		}
 	}