1 files changed, 42 insertions, 4 deletions

diff --git a/source/blender/blenkernel/intern/subsurf_ccg.c b/source/blender/blenkernel/intern/subsurf_ccg.c
index 72236a76032..53206bb3970 100644
--- a/source/blender/blenkernel/intern/subsurf_ccg.c
+++ b/source/blender/blenkernel/intern/subsurf_ccg.c
@@ -44,6 +44,7 @@
 #include "BKE_cdderivedmesh.h"
 #include "BKE_global.h"
 #include "BKE_mesh.h"
+#include "BKE_modifier.h"
 #include "BKE_paint.h"
 #include "BKE_scene.h"
 #include "BKE_subsurf.h"
@@ -2229,10 +2230,28 @@ static ListBase *ccgDM_getFaceMap(Object *ob, DerivedMesh *dm)
 	return ccgdm->fmap;
 }
 
+static int ccgDM_use_grid_pbvh(CCGDerivedMesh *ccgdm)
+{
+	ModifierData *md;
+	MultiresModifierData *mmd= ccgdm->multires.mmd;
+
+	/* in sync with sculpt mode, only use multires grid pbvh if we are
+	   the last enabled modifier in the stack, otherwise we use the base
+	   mesh */
+	if(!mmd)
+		return 0;
+	
+	for(md=mmd->modifier.next; md; md= md->next)
+		if(modifier_isEnabled(mmd->modifier.scene, md, eModifierMode_Realtime))
+			return 0;
+	
+	return 1;
+}
+
 static struct PBVH *ccgDM_getPBVH(Object *ob, DerivedMesh *dm)
 {
 	CCGDerivedMesh *ccgdm= (CCGDerivedMesh*)dm;
-	int gridSize, numGrids;
+	int gridSize, numGrids, grid_pbvh;
 
 	if(!ob) {
 		ccgdm->pbvh= NULL;
@@ -2241,13 +2260,30 @@ static struct PBVH *ccgDM_getPBVH(Object *ob, DerivedMesh *dm)
 
 	if(!ob->sculpt)
 		return NULL;
-	if(ob->sculpt->pbvh)
-		ccgdm->pbvh= ob->sculpt->pbvh;
+
+	grid_pbvh = ccgDM_use_grid_pbvh(ccgdm);
+
+	if(ob->sculpt->pbvh) {
+		if(grid_pbvh) {
+			/* pbvh's grids, gridadj and gridfaces points to data inside ccgdm
+			   but this can be freed on ccgdm release, this updates the pointers
+			   when the ccgdm gets remade, the assumption is that the topology
+			   does not change. */
+			ccgdm_create_grids(dm);
+			BLI_pbvh_grids_update(ob->sculpt->pbvh, ccgdm->gridData, ccgdm->gridAdjacency, (void**)ccgdm->gridFaces);
+		}
+
+		ccgdm->pbvh = ob->sculpt->pbvh;
+		ccgdm->pbvh_draw = grid_pbvh;
+	}
 
 	if(ccgdm->pbvh)
 		return ccgdm->pbvh;
 
-	if(ccgdm->multires.mmd) {
+	/* no pbvh exists yet, we need to create one. only in case of multires
+	   we build a pbvh over the modified mesh, in other cases the base mesh
+	   is being sculpted, so we build a pbvh from that. */
+	if(grid_pbvh) {
 		ccgdm_create_grids(dm);
 
 		gridSize = ccgDM_getGridSize(dm);
@@ -2256,6 +2292,7 @@ static struct PBVH *ccgDM_getPBVH(Object *ob, DerivedMesh *dm)
 		ob->sculpt->pbvh= ccgdm->pbvh = BLI_pbvh_new();
 		BLI_pbvh_build_grids(ccgdm->pbvh, ccgdm->gridData, ccgdm->gridAdjacency,
 			numGrids, gridSize, (void**)ccgdm->gridFaces);
+		ccgdm->pbvh_draw = 1;
 	}
 	else if(ob->type == OB_MESH) {
 		Mesh *me= ob->data;
@@ -2263,6 +2300,7 @@ static struct PBVH *ccgDM_getPBVH(Object *ob, DerivedMesh *dm)
 		ob->sculpt->pbvh= ccgdm->pbvh = BLI_pbvh_new();
 		BLI_pbvh_build_mesh(ccgdm->pbvh, me->mface, me->mvert,
 				   me->totface, me->totvert);
+		ccgdm->pbvh_draw = 0;
 	}
 
 	return ccgdm->pbvh;