Save 'deform_only' flag in Mesh.runtime

This flag is copied when converting between DM and Mesh.

This flag is set to true in get_mesh(), to mimick the behaviour of
CDDM_from_mesh_ex. This is necessary for the particle system to work
correctly.

5 files changed, 8 insertions, 2 deletions

diff --git a/source/blender/blenkernel/intern/DerivedMesh.c b/source/blender/blenkernel/intern/DerivedMesh.c
index c58d946cc99..beef57a6867 100644
--- a/source/blender/blenkernel/intern/DerivedMesh.c
+++ b/source/blender/blenkernel/intern/DerivedMesh.c
@@ -749,6 +749,7 @@ void DM_to_mesh(DerivedMesh *dm, Mesh *me, Object *ob, CustomDataMask mask, bool
 	CustomData_copy(&dm->loopData, &tmp.ldata, mask, alloctype, totloop);
 	CustomData_copy(&dm->polyData, &tmp.pdata, mask, alloctype, totpoly);
 	tmp.cd_flag = dm->cd_flag;
+	tmp.runtime.deformed_only = dm->deformedOnly;
 
 	if (CustomData_has_layer(&dm->vertData, CD_SHAPEKEY)) {
 		KeyBlock *kb;
@@ -2397,7 +2398,7 @@ static void mesh_calc_modifiers(
 				append_mask |= CD_MASK_PREVIEW_MLOOPCOL;
 			}
 
-			// dm->deformedOnly = false; // XXX: Does Mesh need this? Looks to be used only by particle system
+			mesh->runtime.deformed_only = false;
 		}
 
 		isPrevDeform = (mti->type == eModifierTypeType_OnlyDeform);
diff --git a/source/blender/blenkernel/intern/cdderivedmesh.c b/source/blender/blenkernel/intern/cdderivedmesh.c
index 46dd376e065..e585c4ca666 100644
--- a/source/blender/blenkernel/intern/cdderivedmesh.c
+++ b/source/blender/blenkernel/intern/cdderivedmesh.c
@@ -608,7 +608,7 @@ DerivedMesh *CDDM_from_mesh_ex(Mesh *mesh, int alloctype)
 	DM_init(dm, DM_TYPE_CDDM, mesh->totvert, mesh->totedge, 0 /* mesh->totface */,
 	        mesh->totloop, mesh->totpoly);
 
-	dm->deformedOnly = 1;
+	dm->deformedOnly = mesh->runtime.deformed_only;
 	dm->cd_flag = mesh->cd_flag;
 
 	if (mesh->runtime.cd_dirty_vert & CD_MASK_NORMAL) {
diff --git a/source/blender/blenkernel/intern/mesh.c b/source/blender/blenkernel/intern/mesh.c
index a64eb5aa071..efafdf949dc 100644
--- a/source/blender/blenkernel/intern/mesh.c
+++ b/source/blender/blenkernel/intern/mesh.c
@@ -553,6 +553,7 @@ void BKE_mesh_copy_data(Main *bmain, Mesh *me_dst, const Mesh *me_src, const int
 	me_dst->edit_btmesh = NULL;
 	me_dst->runtime.batch_cache = NULL;
 	me_dst->runtime.bvh_cache = NULL;
+	me_dst->runtime.deformed_only = me_src->runtime.deformed_only;
 
 	me_dst->mselect = MEM_dupallocN(me_dst->mselect);
 	me_dst->bb = MEM_dupallocN(me_dst->bb);
diff --git a/source/blender/makesdna/DNA_mesh_types.h b/source/blender/makesdna/DNA_mesh_types.h
index 5ce24916c54..4e347cc4363 100644
--- a/source/blender/makesdna/DNA_mesh_types.h
+++ b/source/blender/makesdna/DNA_mesh_types.h
@@ -93,6 +93,9 @@ typedef struct MeshRuntime {
 
 	/** 'BVHCache', for 'BKE_bvhutil.c' */
 	struct LinkNode *bvh_cache;
+
+	int deformed_only; /* set by modifier stack if only deformed from original */
+	char padding[4];
 } MeshRuntime;
 
 typedef struct Mesh {
diff --git a/source/blender/modifiers/intern/MOD_util.c b/source/blender/modifiers/intern/MOD_util.c
index f3da8d054ec..c5593cd004e 100644
--- a/source/blender/modifiers/intern/MOD_util.c
+++ b/source/blender/modifiers/intern/MOD_util.c
@@ -313,6 +313,7 @@ Mesh *get_mesh(
 			        LIB_ID_CREATE_NO_DEG_TAG |
 			        LIB_ID_COPY_NO_PREVIEW,
 			        false);
+			mesh->runtime.deformed_only = 1;
 		}
 
 		/* TODO(sybren): after modifier conversion of DM to Mesh is done, check whether