diff --git a/source/blender/blenkernel/BKE_DerivedMesh.h b/source/blender/blenkernel/BKE_DerivedMesh.h
index 8a72b9ae2a9..f7c771394b8 100644
--- a/source/blender/blenkernel/BKE_DerivedMesh.h
+++ b/source/blender/blenkernel/BKE_DerivedMesh.h
@@ -46,6 +46,7 @@
  */
 
 #include "DNA_customdata_types.h"
+#include "BKE_customdata.h"
 
 struct MVert;
 struct MEdge;
@@ -295,6 +296,12 @@ int DM_release(DerivedMesh *dm);
  */
 void DM_to_mesh(DerivedMesh *dm, struct Mesh *me);
 
+/* set the CD_FLAG_NOCOPY flag in custom data layers where the mask is
+ * zero for the layer type, so only layer types specified by the mask
+ * will be copied
+ */
+void DM_set_only_copy(DerivedMesh *dm, CustomDataMask mask);
+
 /* adds a vertex/edge/face custom data layer to a DerivedMesh, optionally
  * backed by an external data array
  * if layer != NULL, it is used as the layer data array, otherwise new memory
@@ -337,7 +344,7 @@ void DM_set_face_data(struct DerivedMesh *dm, int index, int type, void *data);
 
 /* custom data copy functions
  * copy count elements from source_index in source to dest_index in dest
- * these copy all layers for which the LAYERFLAG_NOCOPY flag is not set
+ * these copy all layers for which the CD_FLAG_NOCOPY flag is not set
  */
 void DM_copy_vert_data(struct DerivedMesh *source, struct DerivedMesh *dest,
                        int source_index, int dest_index, int count);
@@ -396,21 +403,34 @@ void DM_swap_face_data(struct DerivedMesh *dm, int index, int *corner_indices);
 float *mesh_get_mapped_verts_nors(struct Object *ob);
 
 	/* */
-DerivedMesh *mesh_get_derived_final(struct Object *ob);
-DerivedMesh *mesh_get_derived_deform(struct Object *ob);
+DerivedMesh *mesh_get_derived_final(struct Object *ob,
+                                    CustomDataMask dataMask);
+DerivedMesh *mesh_get_derived_deform(struct Object *ob,
+                                     CustomDataMask dataMask);
 
 DerivedMesh *mesh_create_derived_for_modifier(struct Object *ob, struct ModifierData *md);
 
-DerivedMesh *mesh_create_derived_render(struct Object *ob);
-DerivedMesh *mesh_create_derived_view(struct Object *ob); /* same as above but wont use render settings */
-DerivedMesh *mesh_create_derived_no_deform(struct Object *ob, float (*vertCos)[3]);
-DerivedMesh *mesh_create_derived_no_deform_render(struct Object *ob, float (*vertCos)[3]);
+DerivedMesh *mesh_create_derived_render(struct Object *ob,
+                                        CustomDataMask dataMask);
+/* same as above but wont use render settings */
+DerivedMesh *mesh_create_derived_view(struct Object *ob,
+                                      CustomDataMask dataMask);
+DerivedMesh *mesh_create_derived_no_deform(struct Object *ob,
+                                           float (*vertCos)[3],
+                                           CustomDataMask dataMask);
+DerivedMesh *mesh_create_derived_no_deform_render(struct Object *ob,
+                                                  float (*vertCos)[3],
+                                                  CustomDataMask dataMask);
 
 DerivedMesh *editmesh_get_derived_base(void);
-DerivedMesh *editmesh_get_derived_cage(void);
-DerivedMesh *editmesh_get_derived_cage_and_final(DerivedMesh **final_r);
+DerivedMesh *editmesh_get_derived_cage(CustomDataMask dataMask);
+DerivedMesh *editmesh_get_derived_cage_and_final(DerivedMesh **final_r,
+                                                 CustomDataMask dataMask);
 
 void weight_to_rgb(float input, float *fr, float *fg, float *fb);
 
+/* determines required DerivedMesh data according to view and edit modes */
+CustomDataMask get_viewedit_datamask();
+
 #endif
 
diff --git a/source/blender/blenkernel/BKE_customdata.h b/source/blender/blenkernel/BKE_customdata.h
index ce32f06e320..d48340998e0 100644
--- a/source/blender/blenkernel/BKE_customdata.h
+++ b/source/blender/blenkernel/BKE_customdata.h
@@ -36,9 +36,10 @@ struct CustomData;
 struct CustomDataLayer;
 typedef int CustomDataMask;
 
-extern CustomDataMask CD_MASK_MESH[];
-extern CustomDataMask CD_MASK_EDITMESH[];
-extern CustomDataMask CD_MASK_DERIVEDMESH[];
+extern const CustomDataMask CD_MASK_BAREMESH;
+extern const CustomDataMask CD_MASK_MESH;
+extern const CustomDataMask CD_MASK_EDITMESH;
+extern const CustomDataMask CD_MASK_DERIVEDMESH;
 
 /* for ORIGINDEX layer type, indicates no original index for this element */
 #define ORIGINDEX_NONE -1
@@ -54,15 +55,15 @@ extern CustomDataMask CD_MASK_DERIVEDMESH[];
 #define CD_REFERENCE 3  /* reference original pointers, set layer flag NOFREE */
 
 /* initialises a CustomData object with the same layer setup as source.
- * mask must be an array of length CD_NUMTYPES elements, that indicates
+ * mask is a bitfield where (mask & (1 << (layer type))) indicates
  * if a layer should be copied or not. alloctype must be one of the above. */
 void CustomData_copy(const struct CustomData *source, struct CustomData *dest,
-                     CustomDataMask *mask, int alloctype, int totelem);
+                     CustomDataMask mask, int alloctype, int totelem);
 
 /* same as the above, except that will preserve existing layers, and only add
  * the layers that were not there yet */
 void CustomData_merge(const struct CustomData *source, struct CustomData *dest,
-                      CustomDataMask *mask, int alloctype, int totelem);
+                      CustomDataMask mask, int alloctype, int totelem);
 
 /* frees data associated with a CustomData object (doesn't free the object
  * itself, though)
@@ -105,6 +106,13 @@ int CustomData_has_layer(const struct CustomData *data, int type);
  * returns the layer data */
 void *CustomData_duplicate_referenced_layer(struct CustomData *data, int type);
 
+/* set the CD_FLAG_NOCOPY flag in custom data layers where the mask is
+ * zero for the layer type, so only layer types specified by the mask
+ * will be copied
+ */
+void CustomData_set_only_copy(const struct CustomData *data,
+                              CustomDataMask mask);
+
 /* copies data from one CustomData object to another
  * objects need not be compatible, each source layer is copied to the
  * first dest layer of correct type (if there is none, the layer is skipped)
@@ -191,4 +199,7 @@ void CustomData_from_em_block(const struct CustomData *source,
 void CustomData_file_write_info(int type, char **structname, int *structnum);
 int CustomData_sizeof(int type);
 
+/* get the name of a layer type */
+const char *CustomData_layertype_name(int type);
+
 #endif
diff --git a/source/blender/blenkernel/BKE_displist.h b/source/blender/blenkernel/BKE_displist.h
index 04f3aadbe3c..979ed31fb20 100644
--- a/source/blender/blenkernel/BKE_displist.h
+++ b/source/blender/blenkernel/BKE_displist.h
@@ -36,6 +36,7 @@
 #define BKE_DISPLIST_H
 
 #include "DNA_customdata_types.h"
+#include "BKE_customdata.h"
 
 /* dl->type */
 #define DL_POLY                 0
@@ -109,7 +110,7 @@ extern void addnormalsDispList(struct Object *ob, struct ListBase *lb);
 extern void count_displist(struct ListBase *lb, int *totvert, int *totface);
 extern void freedisplist(struct ListBase *lb);
 extern int displist_has_faces(struct ListBase *lb);
-extern void makeDerivedMesh(struct Object *ob);
+extern void makeDerivedMesh(struct Object *ob, CustomDataMask dataMask);
 extern void makeDispListSurf(struct Object *ob, struct ListBase *dispbase, int forRender);
 extern void makeDispListCurveTypes(struct Object *ob, int forOrco);
 extern void makeDispListMBall(struct Object *ob);
diff --git a/source/blender/blenkernel/BKE_modifier.h b/source/blender/blenkernel/BKE_modifier.h
index a4c050429e5..586ee4e8552 100644
--- a/source/blender/blenkernel/BKE_modifier.h
+++ b/source/blender/blenkernel/BKE_modifier.h
@@ -33,12 +33,15 @@
 #ifndef BKE_MODIFIER_H
 #define BKE_MODIFIER_H
 
+#include "BKE_customdata.h"
+
 struct EditMesh;
 struct DerivedMesh;
 struct DagForest;
 struct DagNode;
 struct Object;
 struct ListBase;
+struct LinkNode;
 struct bArmature;
 
 typedef enum {
@@ -102,7 +105,6 @@ typedef struct ModifierTypeInfo {
 	 */
 	void (*copyData)(ModifierData *md, ModifierData *target);
 
-
 	/********************* Deform modifier functions *********************/
 
 	/* Only for deform types, should apply the deformation
@@ -170,6 +172,24 @@ typedef struct ModifierTypeInfo {
 	 */
 	void (*initData)(ModifierData *md);
 
+	/* Should return a CustomDataMask indicating what data this
+	 * modifier needs. If (mask & (1 << (layer type))) != 0, this modifier
+	 * needs that custom data layer. This function's return value can change
+	 * depending on the modifier's settings.
+	 *
+	 * Note that this means extra data (e.g. vertex groups) - it is assumed
+	 * that all modifiers need mesh data and deform modifiers need vertex
+	 * coordinates.
+	 *
+	 * Note that this limits the number of custom data layer types to 32.
+	 *
+	 * If this function is not present or it returns 0, it is assumed that
+	 * no extra data is needed.
+	 *
+	 * This function is optional.
+	 */
+	CustomDataMask (*requiredDataMask)(ModifierData *md);
+
 	/* Free internal modifier data variables, this function should
 	 * not free the md variable itself.
 	 *
@@ -253,6 +273,13 @@ struct Object *modifiers_isDeformedByArmature(struct Object *ob);
 int           modifiers_usesArmature(struct Object *ob, struct bArmature *arm);
 int           modifiers_isDeformed(struct Object *ob);
 
+/* Calculates and returns a linked list of CustomDataMasks indicating the
+ * data required by each modifier in the stack pointed to by md for correct
+ * evaluation, assuming the data indicated by dataMask is required at the
+ * end of the stack.
+ */
+struct LinkNode *modifiers_calcDataMasks(ModifierData *md,
+                                         CustomDataMask dataMask);
 ModifierData  *modifiers_getVirtualModifierList(struct Object *ob);
 
 #endif
diff --git a/source/blender/blenkernel/intern/DerivedMesh.c b/source/blender/blenkernel/intern/DerivedMesh.c
index 462a5c09387..8c3e807abd9 100644
--- a/source/blender/blenkernel/intern/DerivedMesh.c
+++ b/source/blender/blenkernel/intern/DerivedMesh.c
@@ -51,11 +51,15 @@
 #include "DNA_object_force.h"
 #include "DNA_object_fluidsim.h" // N_T
 #include "DNA_scene_types.h" // N_T
+#include "DNA_view3d_types.h"
+#include "DNA_screen_types.h"
+#include "DNA_space_types.h"
 
 #include "BLI_arithb.h"
 #include "BLI_blenlib.h"
 #include "BLI_edgehash.h"
 #include "BLI_editVert.h"
+#include "BLI_linklist.h"
 
 #include "BKE_utildefines.h"
 #include "BKE_cdderivedmesh.h"
@@ -271,6 +275,13 @@ void DM_to_mesh(DerivedMesh *dm, Mesh *me)
 	*me = tmp;
 }
 
+void DM_set_only_copy(DerivedMesh *dm, CustomDataMask mask)
+{
+	CustomData_set_only_copy(&dm->vertData, mask);
+	CustomData_set_only_copy(&dm->edgeData, mask);
+	CustomData_set_only_copy(&dm->faceData, mask);
+}
+
 void DM_add_vert_layer(DerivedMesh *dm, int type, int flag, void *layer)
 {
 	CustomData_add_layer(&dm->vertData, type, flag, layer, dm->numVertData);
@@ -1554,13 +1565,45 @@ DerivedMesh *mesh_create_derived_for_modifier(Object *ob, ModifierData *md)
 	return dm;
 }
 
+CustomDataMask get_viewedit_datamask()
+{
+	CustomDataMask mask = CD_MASK_BAREMESH;
+	ScrArea *sa;
+
+	/* check if we need tfaces & mcols due to face select or texture paint */
+	if(G.f & G_FACESELECT || G.f & G_TEXTUREPAINT) {
+		mask |= CD_MASK_MTFACE | CD_MASK_MCOL;
+	} else {
+		/* check if we need tfaces & mcols due to view mode */
+		for(sa = G.curscreen->areabase.first; sa; sa = sa->next) {
+			if(sa->spacetype == SPACE_VIEW3D) {
+				View3D *view = sa->spacedata.first;
+				if(view->drawtype == OB_SHADED) {
+					/* this includes normals for mesh_create_shadedColors */
+					mask |= CD_MASK_MTFACE | CD_MASK_MCOL | CD_MASK_NORMAL;
+				}
+				if(view->drawtype == OB_TEXTURE) {
+					mask |= CD_MASK_MTFACE | CD_MASK_MCOL;
+				}
+			}
+		}
+	}
+
+	/* check if we need mcols due to vertex paint or weightpaint */
+	if(G.f & G_VERTEXPAINT || G.f & G_WEIGHTPAINT)
+		mask |= CD_MASK_MCOL;
+
+	return mask;
+}
+
 static void mesh_calc_modifiers(Object *ob, float (*inputVertexCos)[3],
                                 DerivedMesh **deform_r, DerivedMesh **final_r,
                                 int useRenderParams, int useDeform,
-                                int needMapping)
+                                int needMapping, CustomDataMask dataMask)
 {
 	Mesh *me = ob->data;
 	ModifierData *md = modifiers_getVirtualModifierList(ob);
+	LinkNode *datamasks, *curr;
 	float (*deformedVerts)[3] = NULL;
 	DerivedMesh *dm;
 	int numVerts = me->totvert;
@@ -1569,6 +1612,12 @@ static void mesh_calc_modifiers(Object *ob, float (*inputVertexCos)[3],
 
 	modifiers_clearErrors(ob);
 
+	/* we always want to keep original indices */
+	dataMask |= CD_MASK_ORIGINDEX;
+
+	datamasks = modifiers_calcDataMasks(md, dataMask);
+	curr = datamasks;
+
 	if(deform_r) *deform_r = NULL;
 	*final_r = NULL;
 
@@ -1596,7 +1645,7 @@ static void mesh_calc_modifiers(Object *ob, float (*inputVertexCos)[3],
 			deformedVerts = mesh_getVertexCos(me, &numVerts);
 		
 		/* Apply all leading deforming modifiers */
-		for(; md; md = md->next) {
+		for(; md; md = md->next, curr = curr->next) {
 			ModifierTypeInfo *mti = modifierType_getInfo(md->type);
 
 			if((md->mode & required_mode) != required_mode) continue;
@@ -1659,7 +1708,7 @@ static void mesh_calc_modifiers(Object *ob, float (*inputVertexCos)[3],
 	if(me->vnode) dm = derivedmesh_from_versemesh(me->vnode, deformedVerts);
 #endif
 
-	for(; md; md = md->next) {
+	for(; md; md = md->next, curr = curr->next) {
 		ModifierTypeInfo *mti = modifierType_getInfo(md->type);
 
 		if((md->mode & required_mode) != required_mode) continue;
@@ -1717,6 +1766,9 @@ static void mesh_calc_modifiers(Object *ob, float (*inputVertexCos)[3],
 				}
 			}
 
+			/* set the DerivedMesh to only copy needed data */
+			DM_set_only_copy(dm, (CustomDataMask)curr->link);
+
 			ndm = mti->applyModifier(md, ob, dm, useRenderParams,
 			                         !inputVertexCos);
 
@@ -1772,6 +1824,8 @@ static void mesh_calc_modifiers(Object *ob, float (*inputVertexCos)[3],
 	if(deformedVerts && deformedVerts != inputVertexCos)
 		MEM_freeN(deformedVerts);
 
+	BLI_linklist_free(datamasks, NULL);
+
 	/* restore mesh in any case */
 	if(fluidsimMeshUsed) ob->data = ob->fluidsimSettings->orgMesh;
 }
@@ -1790,7 +1844,9 @@ static float (*editmesh_getVertexCos(EditMesh *em, int *numVerts_r))[3]
 	return cos;
 }
 
-static void editmesh_calc_modifiers(DerivedMesh **cage_r, DerivedMesh **final_r)
+static void editmesh_calc_modifiers(DerivedMesh **cage_r,
+                                    DerivedMesh **final_r,
+                                    CustomDataMask dataMask)
 {
 	Object *ob = G.obedit;
 	EditMesh *em = G.editMesh;
@@ -1799,6 +1855,7 @@ static void editmesh_calc_modifiers(DerivedMesh **cage_r, DerivedMesh **final_r)
 	DerivedMesh *dm;
 	int i, numVerts = 0, cageIndex = modifiers_getCageIndex(ob, NULL);
 	int required_mode = eModifierMode_Realtime | eModifierMode_Editmode;
+	LinkNode *datamasks, *curr;
 
 	modifiers_clearErrors(ob);
 
@@ -1807,7 +1864,15 @@ static void editmesh_calc_modifiers(DerivedMesh **cage_r, DerivedMesh **final_r)
 	}
 
 	dm = NULL;
-	for(i = 0, md = ob->modifiers.first; md; i++, md = md->next) {
+	md = ob->modifiers.first;
+
+	/* we always want to keep original indices */
+	dataMask |= CD_MASK_ORIGINDEX;
+
+	datamasks = modifiers_calcDataMasks(md, dataMask);
+
+	curr = datamasks;
+	for(i = 0; md; i++, md = md->next, curr = curr->next) {
 		ModifierTypeInfo *mti = modifierType_getInfo(md->type);
 
 		if((md->mode & required_mode) != required_mode) continue;
@@ -1869,6 +1934,9 @@ static void editmesh_calc_modifiers(DerivedMesh **cage_r, DerivedMesh **final_r)
 				}
 			}
 
+			/* set the DerivedMesh to only copy needed data */
+			DM_set_only_copy(dm, (CustomDataMask)curr->link);
+
 			ndm = mti->applyModifierEM(md, ob, em, dm);
 
 			if (ndm) {
@@ -1898,6 +1966,8 @@ static void editmesh_calc_modifiers(DerivedMesh **cage_r, DerivedMesh **final_r)
 		}
 	}
 
+	BLI_linklist_free(datamasks, NULL);
+
 	/* Yay, we are done. If we have a DerivedMesh and deformed vertices need
 	 * to apply these back onto the DerivedMesh. If we have no DerivedMesh
 	 * then we need to build one.
@@ -2020,7 +2090,7 @@ static void clear_mesh_caches(Object *ob)
 	}
 }
 
-static void mesh_build_data(Object *ob)
+static void mesh_build_data(Object *ob, CustomDataMask dataMask)
 {
 	Mesh *me = ob->data;
 	float min[3], max[3];
@@ -2046,8 +2116,9 @@ static void mesh_build_data(Object *ob)
 			CustomData_add_layer(&me->fdata, CD_MCOL, CD_FLAG_NOFREE, wpcol, me->totface);
 			me->mcol= wpcol;
 
-			mesh_calc_modifiers(ob, NULL, &ob->derivedDeform, &ob->derivedFinal, 0, 1,
-			                    needMapping);
+			mesh_calc_modifiers(ob, NULL, &ob->derivedDeform,
+			                    &ob->derivedFinal, 0, 1,
+			                    needMapping, dataMask);
 
 			CustomData_free_layer(&me->fdata, CD_MCOL, me->totface);
 			if (wpcol) MEM_freeN(wpcol);
@@ -2057,7 +2128,8 @@ static void mesh_build_data(Object *ob)
 			me->mcol= mcol;
 		} else {
 			mesh_calc_modifiers(ob, NULL, &ob->derivedDeform,
-			                    &ob->derivedFinal, 0, 1, needMapping);
+			                    &ob->derivedFinal, 0, 1,
+			                    needMapping, dataMask);
 		}
 
 		INIT_MINMAX(min, max);
@@ -2068,10 +2140,11 @@ static void mesh_build_data(Object *ob)
 
 		ob->derivedFinal->needsFree = 0;
 		ob->derivedDeform->needsFree = 0;
+		ob->lastDataMask = dataMask;
 	}
 }
 
-static void editmesh_build_data(void)
+static void editmesh_build_data(CustomDataMask dataMask)
 {
 	float min[3], max[3];
 
@@ -2092,7 +2165,8 @@ static void editmesh_build_data(void)
 		em->derivedCage = NULL;
 	}
 
-	editmesh_calc_modifiers(&em->derivedCage, &em->derivedFinal);
+	editmesh_calc_modifiers(&em->derivedCage, &em->derivedFinal, dataMask);
+	em->lastDataMask = dataMask;
 
 	INIT_MINMAX(min, max);
 
@@ -2104,14 +2178,14 @@ static void editmesh_build_data(void)
 	em->derivedCage->needsFree = 0;
 }
 
-void makeDerivedMesh(Object *ob)
+void makeDerivedMesh(Object *ob, CustomDataMask dataMask)
 {
 	if (ob==G.obedit) {
-		editmesh_build_data();
+		editmesh_build_data(dataMask);
 	} else {
 		PartEff *paf= give_parteff(ob);
 		
-		mesh_build_data(ob);
+		mesh_build_data(ob, dataMask);
 		
 		if(paf) {
 			if((paf->flag & PAF_STATIC) || (ob->recalc & OB_RECALC_TIME)==0)
@@ -2122,23 +2196,29 @@ void makeDerivedMesh(Object *ob)
 
 /***/
 
-DerivedMesh *mesh_get_derived_final(Object *ob)
+DerivedMesh *mesh_get_derived_final(Object *ob, CustomDataMask dataMask)
 {
-	if (!ob->derivedFinal)
-		mesh_build_data(ob);
+	/* if there's no derived mesh or the last data mask used doesn't include
+	 * the data we need, rebuild the derived mesh
+	 */
+	if(!ob->derivedFinal || (dataMask & ob->lastDataMask) != dataMask)
+		mesh_build_data(ob, dataMask);
 
 	return ob->derivedFinal;
 }
 
-DerivedMesh *mesh_get_derived_deform(Object *ob)
+DerivedMesh *mesh_get_derived_deform(Object *ob, CustomDataMask dataMask)
 {
-	if (!ob->derivedDeform)
-		mesh_build_data(ob);
+	/* if there's no derived mesh or the last data mask used doesn't include
+	 * the data we need, rebuild the derived mesh
+	 */
+	if(!ob->derivedDeform || (dataMask & ob->lastDataMask) != dataMask)
+		mesh_build_data(ob, dataMask);
 
 	return ob->derivedDeform;
 }
 
-DerivedMesh *mesh_create_derived_render(Object *ob)
+DerivedMesh *mesh_create_derived_render(Object *ob, CustomDataMask dataMask)
 {
 	DerivedMesh *final;
 	Mesh *m= get_mesh(ob);
@@ -2150,7 +2230,7 @@ DerivedMesh *mesh_create_derived_render(Object *ob)
 		multires_set_level(ob,m);
 	}
 
-	mesh_calc_modifiers(ob, NULL, NULL, &final, 1, 1, 0);
+	mesh_calc_modifiers(ob, NULL, NULL, &final, 1, 1, 0, dataMask);
 
 	/* Propagate the changes to render level - fails if mesh topology changed */
 	if(m->mr) {
@@ -2170,48 +2250,60 @@ DerivedMesh *mesh_create_derived_render(Object *ob)
 	return final;
 }
 
-DerivedMesh *mesh_create_derived_view(Object *ob)
+DerivedMesh *mesh_create_derived_view(Object *ob, CustomDataMask dataMask)
 {
 	DerivedMesh *final;
 
-	mesh_calc_modifiers(ob, NULL, NULL, &final, 0, 1, 0);
+	mesh_calc_modifiers(ob, NULL, NULL, &final, 0, 1, 0, dataMask);
 
 	return final;
 }
 
-DerivedMesh *mesh_create_derived_no_deform(Object *ob, float (*vertCos)[3])
+DerivedMesh *mesh_create_derived_no_deform(Object *ob, float (*vertCos)[3],
+                                           CustomDataMask dataMask)
 {
 	DerivedMesh *final;
 
-	mesh_calc_modifiers(ob, vertCos, NULL, &final, 0, 0, 0);
+	mesh_calc_modifiers(ob, vertCos, NULL, &final, 0, 0, 0, dataMask);
 
 	return final;
 }
 
-DerivedMesh *mesh_create_derived_no_deform_render(Object *ob, float (*vertCos)[3])
+DerivedMesh *mesh_create_derived_no_deform_render(Object *ob,
+                                                  float (*vertCos)[3],
+                                                  CustomDataMask dataMask)
 {
 	DerivedMesh *final;
 
-	mesh_calc_modifiers(ob, vertCos, NULL, &final, 1, 0, 0);
+	mesh_calc_modifiers(ob, vertCos, NULL, &final, 1, 0, 0, dataMask);
 
 	return final;
 }
 
 /***/
 
-DerivedMesh *editmesh_get_derived_cage_and_final(DerivedMesh **final_r)
+DerivedMesh *editmesh_get_derived_cage_and_final(DerivedMesh **final_r,
+                                                 CustomDataMask dataMask)
 {
-	if (!G.editMesh->derivedCage)
-		editmesh_build_data();
+	/* if there's no derived mesh or the last data mask used doesn't include
+	 * the data we need, rebuild the derived mesh
+	 */
+	if(!G.editMesh->derivedCage ||
+	   (G.editMesh->lastDataMask & dataMask) != dataMask)
+		editmesh_build_data(dataMask);
 
 	*final_r = G.editMesh->derivedFinal;
 	return G.editMesh->derivedCage;
 }
 
-DerivedMesh *editmesh_get_derived_cage(void)
+DerivedMesh *editmesh_get_derived_cage(CustomDataMask dataMask)
 {
-	if (!G.editMesh->derivedCage)
-		editmesh_build_data();
+	/* if there's no derived mesh or the last data mask used doesn't include
+	 * the data we need, rebuild the derived mesh
+	 */
+	if(!G.editMesh->derivedCage ||
+	   (G.editMesh->lastDataMask & dataMask) != dataMask)
+		editmesh_build_data(dataMask);
 
 	return G.editMesh->derivedCage;
 }
@@ -2258,7 +2350,7 @@ float *mesh_get_mapped_verts_nors(Object *ob)
 	if(ob->type!=OB_MESH || me->totvert==0)
 		return NULL;
 	
-	dm= mesh_get_derived_final(ob);
+	dm= mesh_get_derived_final(ob, CD_MASK_BAREMESH);
 	vertexcosnos= MEM_callocN(6*sizeof(float)*me->totvert, "vertexcosnos map");
 	
 	if(dm->foreachMappedVert) {
@@ -2322,7 +2414,7 @@ void writeBobjgz(char *filename, struct Object *ob, int useGlobalCoords, int app
 		return;
 	}
 
-	dm = mesh_create_derived_render(ob);
+	dm = mesh_create_derived_render(ob, CD_MASK_BAREMESH);
 	//dm = mesh_create_derived_no_deform(ob,NULL);
 
 	mvert = dm->getVertArray(dm);
@@ -2426,7 +2518,7 @@ void initElbeemMesh(struct Object *ob,
 	float *verts;
 	int *tris;
 
-	dm = mesh_create_derived_render(ob);
+	dm = mesh_create_derived_render(ob, CD_MASK_BAREMESH);
 	//dm = mesh_create_derived_no_deform(ob,NULL);
 	if(!dm) { *numVertices = *numTriangles = 0; *triangles=NULL; *vertices=NULL; }
 
diff --git a/source/blender/blenkernel/intern/anim.c b/source/blender/blenkernel/intern/anim.c
index ad97128bb37..849a7f316f2 100644
--- a/source/blender/blenkernel/intern/anim.c
+++ b/source/blender/blenkernel/intern/anim.c
@@ -410,9 +410,9 @@ static void vertex_duplilist(ListBase *lb, Scene *sce, Object *par)
 	lay= G.scene->lay;
 	
 	if(par==G.obedit)
-		dm= editmesh_get_derived_cage();
+		dm= editmesh_get_derived_cage(CD_MASK_BAREMESH);
 	else
-		dm = mesh_get_derived_deform(par);
+		dm = mesh_get_derived_deform(par, CD_MASK_BAREMESH);
 	
 	totvert = dm->getNumVerts(dm);
 
@@ -473,7 +473,7 @@ static void face_duplilist(ListBase *lb, Scene *sce, Object *par)
 	
 	if(par==G.obedit) {
 		int totvert;
-		dm= editmesh_get_derived_cage();
+		dm= editmesh_get_derived_cage(CD_MASK_BAREMESH);
 		
 		totface= dm->getNumFaces(dm);
 		mface= MEM_mallocN(sizeof(MFace)*totface, "mface temp");
@@ -483,7 +483,7 @@ static void face_duplilist(ListBase *lb, Scene *sce, Object *par)
 		dm->copyVertArray(dm, mvert);
 	}
 	else {
-		dm = mesh_get_derived_deform(par);
+		dm = mesh_get_derived_deform(par, CD_MASK_BAREMESH);
 		
 		totface= dm->getNumFaces(dm);
 		mface= dm->getFaceArray(dm);
diff --git a/source/blender/blenkernel/intern/customdata.c b/source/blender/blenkernel/intern/customdata.c
index 422107fa273..508021ef74c 100644
--- a/source/blender/blenkernel/intern/customdata.c
+++ b/source/blender/blenkernel/intern/customdata.c
@@ -374,12 +374,17 @@ const char *LAYERTYPENAMES[CD_NUMTYPES] = {
 	"CDMVert", "CDMSticky", "CDMDeformVert", "CDMEdge", "CDMFace", "CDMTFace",
 	"CDMCol", "CDOrigIndex", "CDNormal", "CDFlags"};
 
-CustomDataMask CD_MASK_MESH[CD_NUMTYPES] = {
-	1, 1, 1, 1, 1, 1, 1, 0, 0, 0};
-CustomDataMask CD_MASK_EDITMESH[CD_NUMTYPES] = {
-	0, 1, 1, 0, 0, 1, 1, 0, 0, 0};
-CustomDataMask CD_MASK_DERIVEDMESH[CD_NUMTYPES] = {
-	0, 1, 1, 0, 0, 1, 1, 1, 0, 0};
+const CustomDataMask CD_MASK_BAREMESH =
+	CD_MASK_MVERT | CD_MASK_MEDGE | CD_MASK_MFACE;
+const CustomDataMask CD_MASK_MESH =
+	CD_MASK_MVERT | CD_MASK_MEDGE | CD_MASK_MFACE |
+	CD_MASK_MSTICKY | CD_MASK_MDEFORMVERT | CD_MASK_MTFACE | CD_MASK_MCOL;
+const CustomDataMask CD_MASK_EDITMESH =
+	CD_MASK_MSTICKY | CD_MASK_MDEFORMVERT | CD_MASK_MTFACE |
+	CD_MASK_MCOL;
+const CustomDataMask CD_MASK_DERIVEDMESH =
+	CD_MASK_MSTICKY | CD_MASK_MDEFORMVERT | CD_MASK_MTFACE |
+	CD_MASK_MCOL | CD_MASK_ORIGINDEX;
 
 static const LayerTypeInfo *layerType_getInfo(int type)
 {
@@ -412,7 +417,7 @@ static void CustomData_update_offsets(CustomData *data)
 }
 
 void CustomData_merge(const struct CustomData *source, struct CustomData *dest,
-                      CustomDataMask *mask, int alloctype, int totelem)
+                      CustomDataMask mask, int alloctype, int totelem)
 {
 	const LayerTypeInfo *typeInfo;
 	CustomDataLayer *layer;
@@ -424,7 +429,7 @@ void CustomData_merge(const struct CustomData *source, struct CustomData *dest,
 		typeInfo = layerType_getInfo(layer->type);
 
 		if(layer->flag & CD_FLAG_NOCOPY) continue;
-		else if(mask && !mask[layer->type]) continue;
+		else if(!(mask & (1 << layer->type))) continue;
 		else if(CustomData_has_layer(dest, layer->type)) continue;
 
 		type = layer->type;
@@ -451,7 +456,7 @@ void CustomData_merge(const struct CustomData *source, struct CustomData *dest,
 }
 
 void CustomData_copy(const struct CustomData *source, struct CustomData *dest,
-                     CustomDataMask *mask, int alloctype, int totelem)
+                     CustomDataMask mask, int alloctype, int totelem)
 {
 	memset(dest, 0, sizeof(*dest));
 
@@ -650,6 +655,16 @@ int CustomData_compat(const CustomData *data1, const CustomData *data2)
 	return 1;
 }
 
+void CustomData_set_only_copy(const struct CustomData *data,
+                              CustomDataMask mask)
+{
+	int i;
+
+	for(i = 0; i < data->totlayer; ++i)
+		if(!(mask & (1 << data->layers[i].type)))
+			data->layers[i].flag |= CD_FLAG_NOCOPY;
+}
+
 void CustomData_copy_data(const CustomData *source, CustomData *dest,
                           int source_index, int dest_index, int count)
 {
@@ -1109,3 +1124,8 @@ int CustomData_sizeof(int type)
 
 	return type_info->size;
 }
+
+const char *CustomData_layertype_name(int type)
+{
+	return layerType_getName(type);
+}
diff --git a/source/blender/blenkernel/intern/displist.c b/source/blender/blenkernel/intern/displist.c
index 763a4cdc0a0..1cedbe1338e 100644
--- a/source/blender/blenkernel/intern/displist.c
+++ b/source/blender/blenkernel/intern/displist.c
@@ -449,15 +449,17 @@ static void mesh_create_shadedColors(Render *re, Object *ob, int onlyForMesh, un
 	unsigned int *col1, *col2;
 	float *orco, *vnors, *nors, imat[3][3], mat[4][4], vec[3];
 	int a, i, need_orco, totface, totvert;
+	CustomDataMask dataMask = CD_MASK_BAREMESH | CD_MASK_MCOL
+	                          | CD_MASK_MTFACE | CD_MASK_NORMAL;
 
 	init_fastshade_for_ob(re, ob, &need_orco, mat, imat);
 
 	orco = (need_orco)? mesh_create_orco(ob): NULL;
 
 	if (onlyForMesh)
-		dm = mesh_get_derived_deform(ob);
+		dm = mesh_get_derived_deform(ob, dataMask);
 	else
-		dm = mesh_get_derived_final(ob);
+		dm = mesh_get_derived_final(ob, dataMask);
 	
 	mvert = dm->getVertArray(dm);
 	mface = dm->getFaceArray(dm);
@@ -474,7 +476,7 @@ static void mesh_create_shadedColors(Render *re, Object *ob, int onlyForMesh, un
 		*col1_r = col1 = MEM_mallocN(sizeof(*col1)*totface*4, "col1");
 
 		if (col2_r && (me->flag & ME_TWOSIDED))
-			col2 = MEM_mallocN(sizeof(*col2)*totface*4, "col1");
+			col2 = MEM_mallocN(sizeof(*col2)*totface*4, "col2");
 		else
 			col2 = NULL;
 		
diff --git a/source/blender/blenkernel/intern/exotic.c b/source/blender/blenkernel/intern/exotic.c
index 0848d2b71a0..4946066e4b3 100644
--- a/source/blender/blenkernel/intern/exotic.c
+++ b/source/blender/blenkernel/intern/exotic.c
@@ -2495,7 +2495,7 @@ static int write_derivedmesh_stl(FILE *fpSTL, Object *ob, DerivedMesh *dm)
 static int write_object_stl(FILE *fpSTL, Object *ob, Mesh *me)
 {
 	int  numfacets = 0;
-	DerivedMesh *dm = mesh_get_derived_final(ob);
+	DerivedMesh *dm = mesh_get_derived_final(ob, CD_MASK_BAREMESH);
 
 	numfacets += write_derivedmesh_stl(fpSTL, ob, dm);
 
@@ -2649,7 +2649,7 @@ static void write_videoscape_mesh(Object *ob, char *str)
 		}
 	}
 	else {
-		DerivedMesh *dm = mesh_get_derived_deform(ob);
+		DerivedMesh *dm = mesh_get_derived_deform(ob, CD_MASK_BAREMESH);
 		
 		me= ob->data;
 		
diff --git a/source/blender/blenkernel/intern/mesh.c b/source/blender/blenkernel/intern/mesh.c
index 6de2717ba46..52c094acca4 100644
--- a/source/blender/blenkernel/intern/mesh.c
+++ b/source/blender/blenkernel/intern/mesh.c
@@ -505,9 +505,9 @@ static float *make_orco_mesh_internal(Object *ob, int render)
 		/* Apply orco-changing modifiers */
 
 	if (render) {
-		dm = mesh_create_derived_no_deform_render(ob, vcos);
+		dm = mesh_create_derived_no_deform_render(ob, vcos, CD_MASK_BAREMESH);
 	} else {
-		dm = mesh_create_derived_no_deform(ob, vcos);
+		dm = mesh_create_derived_no_deform(ob, vcos, CD_MASK_BAREMESH);
 	}
 	totvert = dm->getNumVerts(dm);
 
diff --git a/source/blender/blenkernel/intern/modifier.c b/source/blender/blenkernel/intern/modifier.c
index b1037da270e..43c513aaa1b 100644
--- a/source/blender/blenkernel/intern/modifier.c
+++ b/source/blender/blenkernel/intern/modifier.c
@@ -119,6 +119,17 @@ static void curveModifier_copyData(ModifierData *md, ModifierData *target)
 	strncpy(tcmd->name, cmd->name, 32);
 }
 
+CustomDataMask curveModifier_requiredDataMask(ModifierData *md)
+{
+	CurveModifierData *cmd = (CurveModifierData *)md;
+	CustomDataMask dataMask = 0;
+
+	/* ask for vertexgroups if we need them */
+	if(cmd->name[0]) dataMask |= (1 << CD_MDEFORMVERT);
+
+	return dataMask;
+}
+
 static int curveModifier_isDisabled(ModifierData *md)
 {
 	CurveModifierData *cmd = (CurveModifierData*) md;
@@ -184,6 +195,17 @@ static void latticeModifier_copyData(ModifierData *md, ModifierData *target)
 	strncpy(tlmd->name, lmd->name, 32);
 }
 
+CustomDataMask latticeModifier_requiredDataMask(ModifierData *md)
+{
+	LatticeModifierData *lmd = (LatticeModifierData *)md;
+	CustomDataMask dataMask = 0;
+
+	/* ask for vertexgroups if we need them */
+	if(lmd->name[0]) dataMask |= (1 << CD_MDEFORMVERT);
+
+	return dataMask;
+}
+
 static int latticeModifier_isDisabled(ModifierData *md)
 {
 	LatticeModifierData *lmd = (LatticeModifierData*) md;
@@ -2203,6 +2225,20 @@ static void displaceModifier_copyData(ModifierData *md, ModifierData *target)
 	*tdmd = *dmd;
 }
 
+CustomDataMask displaceModifier_requiredDataMask(ModifierData *md)
+{
+	DisplaceModifierData *dmd = (DisplaceModifierData *)md;
+	CustomDataMask dataMask = 0;
+
+	/* ask for vertexgroups if we need them */
+	if(dmd->defgrp_name[0]) dataMask |= (1 << CD_MDEFORMVERT);
+
+	/* ask for UV coordinates if we need them */
+	if(dmd->texmapping == MOD_DISP_MAP_UV) dataMask |= (1 << CD_MTFACE);
+
+	return dataMask;
+}
+
 static void displaceModifier_foreachObjectLink(ModifierData *md, Object *ob,
                                          ObjectWalkFunc walk, void *userData)
 {
@@ -2496,6 +2532,16 @@ static void uvprojectModifier_copyData(ModifierData *md, ModifierData *target)
 	tumd->aspecty = umd->aspecty;
 }
 
+CustomDataMask uvprojectModifier_requiredDataMask(ModifierData *md)
+{
+	CustomDataMask dataMask = 0;
+
+	/* ask for UV coordinates */
+	dataMask |= (1 << CD_MTFACE);
+
+	return dataMask;
+}
+
 static void uvprojectModifier_foreachObjectLink(ModifierData *md, Object *ob,
                                         ObjectWalkFunc walk, void *userData)
 {
@@ -3054,6 +3100,16 @@ static void armatureModifier_copyData(ModifierData *md, ModifierData *target)
 	strncpy(tamd->defgrp_name, amd->defgrp_name, 32);
 }
 
+CustomDataMask armatureModifier_requiredDataMask(ModifierData *md)
+{
+	CustomDataMask dataMask = 0;
+
+	/* ask for vertexgroups */
+	dataMask |= (1 << CD_MDEFORMVERT);
+
+	return dataMask;
+}
+
 static int armatureModifier_isDisabled(ModifierData *md)
 {
 	ArmatureModifierData *amd = (ArmatureModifierData*) md;
@@ -3134,6 +3190,17 @@ static void hookModifier_copyData(ModifierData *md, ModifierData *target)
 	strncpy(thmd->name, hmd->name, 32);
 }
 
+CustomDataMask hookModifier_requiredDataMask(ModifierData *md)
+{
+	HookModifierData *hmd = (HookModifierData *)md;
+	CustomDataMask dataMask = 0;
+
+	/* ask for vertexgroups if we need them */
+	if(!hmd->indexar && hmd->name[0]) dataMask |= (1 << CD_MDEFORMVERT);
+
+	return dataMask;
+}
+
 static void hookModifier_freeData(ModifierData *md)
 {
 	HookModifierData *hmd = (HookModifierData*) md;
@@ -3413,6 +3480,7 @@ ModifierTypeInfo *modifierType_getInfo(ModifierType type)
 		             | eModifierTypeFlag_SupportsEditmode;
 		mti->initData = curveModifier_initData;
 		mti->copyData = curveModifier_copyData;
+		mti->requiredDataMask = curveModifier_requiredDataMask;
 		mti->isDisabled = curveModifier_isDisabled;
 		mti->foreachObjectLink = curveModifier_foreachObjectLink;
 		mti->updateDepgraph = curveModifier_updateDepgraph;
@@ -3424,6 +3492,7 @@ ModifierTypeInfo *modifierType_getInfo(ModifierType type)
 		mti->flags = eModifierTypeFlag_AcceptsCVs
 		             | eModifierTypeFlag_SupportsEditmode;
 		mti->copyData = latticeModifier_copyData;
+		mti->requiredDataMask = latticeModifier_requiredDataMask;
 		mti->isDisabled = latticeModifier_isDisabled;
 		mti->foreachObjectLink = latticeModifier_foreachObjectLink;
 		mti->updateDepgraph = latticeModifier_updateDepgraph;
@@ -3490,6 +3559,7 @@ ModifierTypeInfo *modifierType_getInfo(ModifierType type)
 		mti->flags = eModifierTypeFlag_AcceptsMesh|eModifierTypeFlag_SupportsEditmode;
 		mti->initData = displaceModifier_initData;
 		mti->copyData = displaceModifier_copyData;
+		mti->requiredDataMask = displaceModifier_requiredDataMask;
 		mti->foreachObjectLink = displaceModifier_foreachObjectLink;
 		mti->foreachIDLink = displaceModifier_foreachIDLink;
 		mti->updateDepgraph = displaceModifier_updateDepgraph;
@@ -3505,6 +3575,7 @@ ModifierTypeInfo *modifierType_getInfo(ModifierType type)
 		             | eModifierTypeFlag_EnableInEditmode;
 		mti->initData = uvprojectModifier_initData;
 		mti->copyData = uvprojectModifier_copyData;
+		mti->requiredDataMask = uvprojectModifier_requiredDataMask;
 		mti->foreachObjectLink = uvprojectModifier_foreachObjectLink;
 		mti->foreachIDLink = uvprojectModifier_foreachIDLink;
 		mti->updateDepgraph = uvprojectModifier_updateDepgraph;
@@ -3536,6 +3607,7 @@ ModifierTypeInfo *modifierType_getInfo(ModifierType type)
 		             | eModifierTypeFlag_SupportsEditmode;
 		mti->initData = armatureModifier_initData;
 		mti->copyData = armatureModifier_copyData;
+		mti->requiredDataMask = armatureModifier_requiredDataMask;
 		mti->isDisabled = armatureModifier_isDisabled;
 		mti->foreachObjectLink = armatureModifier_foreachObjectLink;
 		mti->updateDepgraph = armatureModifier_updateDepgraph;
@@ -3548,6 +3620,7 @@ ModifierTypeInfo *modifierType_getInfo(ModifierType type)
 		             | eModifierTypeFlag_SupportsEditmode;
 		mti->initData = hookModifier_initData;
 		mti->copyData = hookModifier_copyData;
+		mti->requiredDataMask = hookModifier_requiredDataMask;
 		mti->freeData = hookModifier_freeData;
 		mti->isDisabled = hookModifier_isDisabled;
 		mti->foreachObjectLink = hookModifier_foreachObjectLink;
@@ -3761,6 +3834,46 @@ int modifiers_isSoftbodyEnabled(Object *ob)
 	return (md && md->mode & (eModifierMode_Realtime | eModifierMode_Render));
 }
 
+LinkNode *modifiers_calcDataMasks(ModifierData *md, CustomDataMask dataMask)
+{
+	LinkNode *dataMasks = NULL;
+	LinkNode *curr, *prev;
+
+	/* build a list of modifier data requirements in reverse order */
+	for(; md; md = md->next) {
+		ModifierTypeInfo *mti = modifierType_getInfo(md->type);
+		CustomDataMask mask = 0;
+
+		if(mti->requiredDataMask) mask = mti->requiredDataMask(md);
+
+		BLI_linklist_prepend(&dataMasks, (void *)mask);
+	}
+
+	/* build the list of required data masks - each mask in the list must
+	 * include all elements of the masks that follow it
+	 *
+	 * note the list is currently in reverse order, so "masks that follow it"
+	 * actually means "masks that precede it" at the moment
+	 */
+	for(curr = dataMasks, prev = NULL; curr; prev = curr, curr = curr->next) {
+		if(prev) {
+			CustomDataMask prev_mask = (CustomDataMask)prev->link;
+			CustomDataMask curr_mask = (CustomDataMask)curr->link;
+
+			curr->link = (void *)(curr_mask | prev_mask);
+		} else {
+			CustomDataMask curr_mask = (CustomDataMask)curr->link;
+
+			curr->link = (void *)(curr_mask | dataMask);
+		}
+	}
+
+	/* reverse the list so it's in the correct order */
+	BLI_linklist_reverse(&dataMasks);
+
+	return dataMasks;
+}
+
 ModifierData *modifiers_getVirtualModifierList(Object *ob)
 {
 		/* Kinda hacky, but should be fine since we are never
diff --git a/source/blender/blenkernel/intern/object.c b/source/blender/blenkernel/intern/object.c
index af2d562b331..a8bf87c966f 100644
--- a/source/blender/blenkernel/intern/object.c
+++ b/source/blender/blenkernel/intern/object.c
@@ -2007,7 +2007,7 @@ void object_handle_update(Object *ob)
 			
 			/* includes all keys and modifiers */
 			if(ob->type==OB_MESH) {
-				makeDerivedMesh(ob);
+				makeDerivedMesh(ob, get_viewedit_datamask());
 			}
 			else if(ob->type==OB_MBALL) {
 				makeDispListMBall(ob);
diff --git a/source/blender/blenkernel/intern/softbody.c b/source/blender/blenkernel/intern/softbody.c
index acbf4df653a..ad3ea337c55 100644
--- a/source/blender/blenkernel/intern/softbody.c
+++ b/source/blender/blenkernel/intern/softbody.c
@@ -492,9 +492,9 @@ void ccd_build_deflector_hache(Object *vertexowner,GHash *hash)
 				DerivedMesh *dm= NULL;
 				
 				if(ob->softflag & OB_SB_COLLFINAL) { /* so maybe someone wants overkill to collide with subsurfed */
-					dm = mesh_get_derived_final(ob);
+					dm = mesh_get_derived_final(ob, CD_MASK_BAREMESH);
 				} else {
-					dm = mesh_get_derived_deform(ob);
+					dm = mesh_get_derived_deform(ob, CD_MASK_BAREMESH);
 				}
 
 				if(dm){
@@ -534,9 +534,9 @@ void ccd_update_deflector_hache(Object *vertexowner,GHash *hash)
 				DerivedMesh *dm= NULL;
 				
 				if(ob->softflag & OB_SB_COLLFINAL) { /* so maybe someone wants overkill to collide with subsurfed */
-					dm = mesh_get_derived_final(ob);
+					dm = mesh_get_derived_final(ob, CD_MASK_BAREMESH);
 				} else {
-					dm = mesh_get_derived_deform(ob);
+					dm = mesh_get_derived_deform(ob, CD_MASK_BAREMESH);
 				}
 				if(dm){
 					ccd_Mesh *ccdmesh = BLI_ghash_lookup(hash,ob);
diff --git a/source/blender/blenkernel/intern/subsurf_ccg.c b/source/blender/blenkernel/intern/subsurf_ccg.c
index 44845ed706b..5f7b656d45a 100644
--- a/source/blender/blenkernel/intern/subsurf_ccg.c
+++ b/source/blender/blenkernel/intern/subsurf_ccg.c
@@ -507,7 +507,7 @@ DerivedMesh *ss_to_cdderivedmesh(CCGSubSurf *ss, int ssFromEditmesh,
 		tface = NULL;
 	}
 
-	if(useSubsurfUv && tface) {
+	if(useSubsurfUv && result->getFaceDataArray(result, CD_MTFACE)) {
 		uvss = _getSubSurf(NULL, ccgSubSurf_getSubdivisionLevels(ss),
 		                   0, 1, 0);
 
@@ -2141,7 +2141,7 @@ static CCGDerivedMesh *getCCGDerivedMesh(CCGSubSurf *ss,
 	}
 	ccgFaceIterator_free(fi);
 
-	if(useSubsurfUv && tface) {
+	if(useSubsurfUv && dm->getFaceDataArray(&ccgdm->dm, CD_MTFACE)) {
 		/* not for editmesh currently */
 		uvss = _getSubSurf(NULL, ccgSubSurf_getSubdivisionLevels(ss),
 		                   0, 1, 0);
diff --git a/source/blender/blenlib/BLI_editVert.h b/source/blender/blenlib/BLI_editVert.h
index d39cd748fb1..e81e7db57ca 100644
--- a/source/blender/blenlib/BLI_editVert.h
+++ b/source/blender/blenlib/BLI_editVert.h
@@ -164,6 +164,10 @@ typedef struct EditMesh
 		 * to derived final, care should be taken on release.
 		 */
 	struct DerivedMesh *derivedCage, *derivedFinal;
+	/* the custom data layer mask that was last used to calculate
+	 * derivedCage and derivedFinal
+	 */
+	int lastDataMask;
 
 	char retopo_mode; /* 0=OFF, 1=ON, 2=PAINT */
 	struct RetopoPaintData *retopo_paint_data;
diff --git a/source/blender/makesdna/DNA_customdata_types.h b/source/blender/makesdna/DNA_customdata_types.h
index 08b0345af8d..00c303c0357 100644
--- a/source/blender/makesdna/DNA_customdata_types.h
+++ b/source/blender/makesdna/DNA_customdata_types.h
@@ -62,6 +62,18 @@ typedef struct CustomData {
 #define CD_FLAGS		9
 #define CD_NUMTYPES		10
 
+/* Bits for CustomDataMask */
+#define CD_MASK_MVERT		(1 << CD_MVERT)
+#define CD_MASK_MSTICKY		(1 << CD_MSTICKY)
+#define CD_MASK_MDEFORMVERT	(1 << CD_MDEFORMVERT)
+#define CD_MASK_MEDGE		(1 << CD_MEDGE)
+#define CD_MASK_MFACE		(1 << CD_MFACE)
+#define CD_MASK_MTFACE		(1 << CD_MTFACE)
+#define CD_MASK_MCOL		(1 << CD_MCOL)
+#define CD_MASK_ORIGINDEX	(1 << CD_ORIGINDEX)
+#define CD_MASK_NORMAL		(1 << CD_NORMAL)
+#define CD_MASK_FLAGS		(1 << CD_FLAGS)
+
 /* CustomData.flag */
 
 /* indicates layer should not be copied by CustomData_from_template or
diff --git a/source/blender/makesdna/DNA_object_types.h b/source/blender/makesdna/DNA_object_types.h
index f9055dfc11b..a27c6520787 100644
--- a/source/blender/makesdna/DNA_object_types.h
+++ b/source/blender/makesdna/DNA_object_types.h
@@ -210,6 +210,8 @@ typedef struct Object {
 	struct FluidsimSettings *fluidsimSettings; /* if fluidsim enabled, store additional settings */
   
 	struct DerivedMesh *derivedDeform, *derivedFinal;
+	int lastDataMask;			/* the custom data layer mask that was last used to calculate derivedDeform and derivedFinal */
+	int pad;
 
 /*#ifdef WITH_VERSE*/
 	void *vnode;			/* pointer at object VerseNode */
diff --git a/source/blender/python/api2_2x/Mesh.c b/source/blender/python/api2_2x/Mesh.c
index 01fce68137d..8e0d5e93284 100644
--- a/source/blender/python/api2_2x/Mesh.c
+++ b/source/blender/python/api2_2x/Mesh.c
@@ -5573,9 +5573,9 @@ static PyObject *Mesh_getFromObject( BPy_Mesh * self, PyObject * args )
 			
 			/* Write the display mesh into the dummy mesh */
 			if (render)
-				dm = mesh_create_derived_render( ob );
+				dm = mesh_create_derived_render( ob, CD_MASK_MESH );
 			else
-				dm = mesh_create_derived_view( ob );
+				dm = mesh_create_derived_view( ob, CD_MASK_MESH );
 			
 			tmpmesh = add_mesh(  );
 			DM_to_mesh( dm, tmpmesh );
diff --git a/source/blender/python/api2_2x/NMesh.c b/source/blender/python/api2_2x/NMesh.c
index 5df435ecb2a..7cd3d74673f 100644
--- a/source/blender/python/api2_2x/NMesh.c
+++ b/source/blender/python/api2_2x/NMesh.c
@@ -1455,7 +1455,7 @@ static PyObject *NMesh_update( PyObject *self, PyObject *a, PyObject *kwd )
 		}
 
 		/* recalculate the derived mesh before trying to use it */
-		makeDerivedMesh(nmesh->object);
+		makeDerivedMesh(nmesh->object, CD_MASK_BAREMESH);
 		make_vertexcol(1);
 
 		countall();
@@ -2557,7 +2557,9 @@ static PyObject *M_NMesh_GetRawFromObject( PyObject * self, PyObject * args )
  		break;
  	case OB_MESH:
  		{
-			DerivedMesh *dm = mesh_create_derived_render( ob );
+ 			CustomDataMask dataMask = CD_MASK_BAREMESH | CD_MASK_MTFACE
+ 			                          | CD_MASK_MCOL;
+			DerivedMesh *dm = mesh_create_derived_render( ob, dataMask );
 			nmesh = new_NMesh_internal( ob->data, dm );
 			dm->release(dm);
  		}
diff --git a/source/blender/render/intern/source/convertblender.c b/source/blender/render/intern/source/convertblender.c
index 7232e0e6e71..6268971bb79 100644
--- a/source/blender/render/intern/source/convertblender.c
+++ b/source/blender/render/intern/source/convertblender.c
@@ -1836,7 +1836,8 @@ static void init_render_mesh(Render *re, Object *ob, Object *par, int only_verts
 		ob->data= me;
 	}
 
-	dm = mesh_create_derived_render(ob);
+	dm = mesh_create_derived_render(ob,
+	                    CD_MASK_BAREMESH | CD_MASK_MTFACE | CD_MASK_MCOL);
 
 	/* (Multires) Now switch the meshes back around */
 	if(me->mr) {
diff --git a/source/blender/src/drawimage.c b/source/blender/src/drawimage.c
index 3d11568a8bc..7e77432158e 100644
--- a/source/blender/src/drawimage.c
+++ b/source/blender/src/drawimage.c
@@ -401,7 +401,8 @@ void draw_tfaces(void)
 				DerivedMesh *dm;
 
 				/* draw final mesh with modifiers applied */
-				dm = mesh_get_derived_final(OBACT);
+				dm = mesh_get_derived_final(OBACT,
+				                            CD_MASK_BAREMESH | CD_MASK_MTFACE);
 
 				glColor3ub(112, 112, 112);
 				if (dm->drawUVEdges) dm->drawUVEdges(dm);
diff --git a/source/blender/src/drawmesh.c b/source/blender/src/drawmesh.c
index ac9940f5a02..c6b0a874ff4 100644
--- a/source/blender/src/drawmesh.c
+++ b/source/blender/src/drawmesh.c
@@ -977,7 +977,7 @@ void draw_tface_mesh(Object *ob, Mesh *me, int dt)
 	
 	if(me==NULL) return;
 
-	dm = mesh_get_derived_final(ob);
+	dm = mesh_get_derived_final(ob, get_viewedit_datamask());
 
 	glShadeModel(GL_SMOOTH);
 
@@ -1031,7 +1031,7 @@ void draw_tface_mesh(Object *ob, Mesh *me, int dt)
 
 		/* drawing game engine text hack */
 		if (!editing && prop && me->tface) {
-			DerivedMesh *ddm = mesh_get_derived_deform(ob);
+			DerivedMesh *ddm = mesh_get_derived_deform(ob, CD_MASK_BAREMESH);
 			MFace *mface= me->mface;
 			MTFace *tface= me->mtface;
 			MCol *mcol= me->mcol;	/* why does mcol exist? */
diff --git a/source/blender/src/drawobject.c b/source/blender/src/drawobject.c
index 5bc188c6ac6..94917c99671 100644
--- a/source/blender/src/drawobject.c
+++ b/source/blender/src/drawobject.c
@@ -1137,7 +1137,7 @@ static void mesh_foreachScreenVert__mapFunc(void *userData, int index, float *co
 void mesh_foreachScreenVert(void (*func)(void *userData, EditVert *eve, int x, int y, int index), void *userData, int clipVerts)
 {
 	struct { void (*func)(void *userData, EditVert *eve, int x, int y, int index); void *userData; int clipVerts; float pmat[4][4], vmat[4][4]; } data;
-	DerivedMesh *dm = editmesh_get_derived_cage();
+	DerivedMesh *dm = editmesh_get_derived_cage(CD_MASK_BAREMESH);
 
 	data.func = func;
 	data.userData = userData;
@@ -1179,7 +1179,7 @@ static void mesh_foreachScreenEdge__mapFunc(void *userData, int index, float *v0
 void mesh_foreachScreenEdge(void (*func)(void *userData, EditEdge *eed, int x0, int y0, int x1, int y1, int index), void *userData, int clipVerts)
 {
 	struct { void (*func)(void *userData, EditEdge *eed, int x0, int y0, int x1, int y1, int index); void *userData; int clipVerts; float pmat[4][4], vmat[4][4]; } data;
-	DerivedMesh *dm = editmesh_get_derived_cage();
+	DerivedMesh *dm = editmesh_get_derived_cage(CD_MASK_BAREMESH);
 
 	data.func = func;
 	data.userData = userData;
@@ -1209,7 +1209,7 @@ static void mesh_foreachScreenFace__mapFunc(void *userData, int index, float *ce
 void mesh_foreachScreenFace(void (*func)(void *userData, EditFace *efa, int x, int y, int index), void *userData)
 {
 	struct { void (*func)(void *userData, EditFace *efa, int x, int y, int index); void *userData; float pmat[4][4], vmat[4][4]; } data;
-	DerivedMesh *dm = editmesh_get_derived_cage();
+	DerivedMesh *dm = editmesh_get_derived_cage(CD_MASK_BAREMESH);
 
 	data.func = func;
 	data.userData = userData;
@@ -2150,7 +2150,8 @@ static int draw_mesh_object(Base *base, int dt, int flag)
 		if (G.obedit!=ob)
 			finalDM = cageDM = editmesh_get_derived_base();
 		else
-			cageDM = editmesh_get_derived_cage_and_final(&finalDM);
+			cageDM = editmesh_get_derived_cage_and_final(&finalDM,
+			                                get_viewedit_datamask());
 
 		if(dt>OB_WIRE) init_gl_materials(ob, 0);	// no transp in editmode, the fancy draw over goes bad then
 		draw_em_fancy(ob, G.editMesh, cageDM, finalDM, dt);
@@ -2167,8 +2168,10 @@ static int draw_mesh_object(Base *base, int dt, int flag)
 		/* don't create boundbox here with mesh_get_bb(), the derived system will make it, puts deformed bb's OK */
 		
 		if(me->totface<=4 || boundbox_clip(ob->obmat, me->bb)) {
-			DerivedMesh *baseDM = mesh_get_derived_deform(ob);
-			DerivedMesh *realDM = mesh_get_derived_final(ob);
+			DerivedMesh *baseDM
+			    = mesh_get_derived_deform(ob, get_viewedit_datamask());
+			DerivedMesh *realDM
+			    = mesh_get_derived_final(ob, get_viewedit_datamask());
 
 			if(dt==OB_SOLID) has_alpha= init_gl_materials(ob, (base->flag & OB_FROMDUPLI)==0);
 			if(baseDM && realDM) draw_mesh_fancy(base, baseDM, realDM, dt, flag);
@@ -4275,7 +4278,7 @@ static int bbs_mesh_wire__setDrawOpts(void *userData, int index)
 
 static void bbs_mesh_solid(Object *ob)
 {
-	DerivedMesh *dm = mesh_get_derived_final(ob);
+	DerivedMesh *dm = mesh_get_derived_final(ob, get_viewedit_datamask());
 	Mesh *me = (Mesh*)ob->data;
 	
 	glColor3ub(0, 0, 0);
@@ -4311,7 +4314,7 @@ void draw_object_backbufsel(Object *ob)
 	switch( ob->type) {
 	case OB_MESH:
 		if(ob==G.obedit) {
-			DerivedMesh *dm = editmesh_get_derived_cage();
+			DerivedMesh *dm = editmesh_get_derived_cage(CD_MASK_BAREMESH);
 
 			EM_init_index_arrays(1, 1, 1);
 
@@ -4356,7 +4359,7 @@ void draw_object_instance(Object *ob, int dt, int outline)
 	if(G.obedit && ob->data==G.obedit->data)
 		edm= editmesh_get_derived_base();
 	else 
-		dm = mesh_get_derived_final(ob);
+		dm = mesh_get_derived_final(ob, CD_MASK_BAREMESH);
 
 	if(dt<=OB_WIRE) {
 		if(dm)
diff --git a/source/blender/src/editface.c b/source/blender/src/editface.c
index fa40d210303..ba9174f0c4d 100644
--- a/source/blender/src/editface.c
+++ b/source/blender/src/editface.c
@@ -1584,7 +1584,7 @@ void texpaint_pick_uv(Object *ob, Mesh *mesh, unsigned int faceindex, short *xy,
 	float v1[2], v2[2], v3[2], v4[2], p[2], w[3];
 	float absw, minabsw;
 	int nvert;
-	DerivedMesh *dm = mesh_get_derived_final(ob);
+	DerivedMesh *dm = mesh_get_derived_final(ob, CD_MASK_BAREMESH);
 	int *index = dm->getFaceDataArray(dm, CD_ORIGINDEX);
 	MTFace *tface = dm->getFaceDataArray(dm, CD_MTFACE), *tf;
 	int numfaces = dm->getNumFaces(dm), a;
diff --git a/source/blender/src/editmesh_mods.c b/source/blender/src/editmesh_mods.c
index f0b1aa7ebd6..bd20e68830d 100644
--- a/source/blender/src/editmesh_mods.c
+++ b/source/blender/src/editmesh_mods.c
@@ -625,7 +625,7 @@ static void draw_dm_mapped_face_center(DerivedMesh *dm, EditFace *efa)
 
 static void unified_select_draw(EditVert *eve, EditEdge *eed, EditFace *efa)
 {
-	DerivedMesh *dm = editmesh_get_derived_cage();
+	DerivedMesh *dm = editmesh_get_derived_cage(CD_MASK_BAREMESH);
 
 	glDrawBuffer(GL_FRONT);
 
diff --git a/source/blender/src/editobject.c b/source/blender/src/editobject.c
index eef50449b8a..a22ed7674f7 100644
--- a/source/blender/src/editobject.c
+++ b/source/blender/src/editobject.c
@@ -2567,7 +2567,7 @@ void convertmenu(void)
 				G.totmesh++;
 
 				/* make new mesh data from the original copy */
-				dm= mesh_get_derived_final(ob1);
+				dm= mesh_get_derived_final(ob1, CD_MASK_MESH);
 				/* dm= mesh_create_derived_no_deform(ob1, NULL);	this was called original (instead of get_derived). man o man why! (ton) */
 				
 				DM_to_mesh(dm, ob1->data);
diff --git a/source/blender/src/poseobject.c b/source/blender/src/poseobject.c
index aa82544217c..f2fe70737a8 100644
--- a/source/blender/src/poseobject.c
+++ b/source/blender/src/poseobject.c
@@ -755,7 +755,7 @@ void pose_adds_vgroups(Object *meshobj)
 	
 	if(poseobj==NULL || (poseobj->flag & OB_POSEMODE)==0) return;
 	
-	dm = mesh_get_derived_final(meshobj);
+	dm = mesh_get_derived_final(meshobj, CD_MASK_BAREMESH);
 	
 	map.meshobj= meshobj;
 	
diff --git a/source/blender/src/transform_conversions.c b/source/blender/src/transform_conversions.c
index 395020ddb68..3dafd08d57e 100755
--- a/source/blender/src/transform_conversions.c
+++ b/source/blender/src/transform_conversions.c
@@ -1521,11 +1521,11 @@ static float *get_crazy_mapped_editverts(void)
 		/* this call disables subsurf and enables the underlying modifier to deform, apparently */
 		modifiers_setOnCage(G.obedit, md);
 		/* make it all over */
-		makeDerivedMesh(G.obedit);
+		makeDerivedMesh(G.obedit, CD_MASK_BAREMESH);
 	}
 	
 	/* now get the cage */
-	dm= editmesh_get_derived_cage();
+	dm= editmesh_get_derived_cage(CD_MASK_BAREMESH);
 
 	vertexcos= MEM_mallocN(3*sizeof(float)*G.totvert, "vertexcos map");
 	dm->foreachMappedVert(dm, make_vertexcos__mapFunc, vertexcos);
diff --git a/source/blender/src/verse_object.c b/source/blender/src/verse_object.c
index 6f6113b75dc..2a285d828b9 100644
--- a/source/blender/src/verse_object.c
+++ b/source/blender/src/verse_object.c
@@ -414,7 +414,7 @@ void b_verse_unsubscribe(VNode *vnode)
 		}
 		
 		/* reinitialize object derived mesh */
-		makeDerivedMesh(ob);
+		makeDerivedMesh(ob, get_viewedit_datamask());
 		DAG_object_flush_update(G.scene, ob, OB_RECALC_DATA);
 	}
 	else if(vnode->type==V_NT_BITMAP) {
@@ -445,7 +445,7 @@ void post_link_set(VLink *vlink)
 			me = (Mesh*)((VGeomData*)target->data)->mesh;
 		if(ob && me && ob->data!=me)  {
 			ob->data = me;
-			makeDerivedMesh(ob);
+			makeDerivedMesh(ob, get_viewedit_datamask());
 		}
 	}
 
diff --git a/source/blender/src/vpaint.c b/source/blender/src/vpaint.c
index 916bca354e0..6ee817aeb5f 100644
--- a/source/blender/src/vpaint.c
+++ b/source/blender/src/vpaint.c
@@ -988,7 +988,7 @@ static void sample_wpaint(int mode)
 			extern float editbutvweight;
 			float w1, w2, w3, w4, co[3], fac;
 			
-			dm = mesh_get_derived_final(ob);
+			dm = mesh_get_derived_final(ob, CD_MASK_BAREMESH);
 			if(dm->getVertCo==NULL) {
 				notice("Not supported yet");
 			}