1 files changed, 36 insertions, 6 deletions

diff --git a/source/blender/blenkernel/intern/material.c b/source/blender/blenkernel/intern/material.c
index d4de04a9e98..e878a894b27 100644
--- a/source/blender/blenkernel/intern/material.c
+++ b/source/blender/blenkernel/intern/material.c
@@ -955,18 +955,26 @@ void BKE_object_material_remap_calc(Object *ob_dst, Object *ob_src, short *remap
 void BKE_object_material_array_assign(Main *bmain,
                                       struct Object *ob,
                                       struct Material ***matar,
-                                      short totcol)
+                                      int totcol,
+                                      const bool to_object_only)
 {
   int actcol_orig = ob->actcol;
-  short i;
 
   while ((ob->totcol > totcol) && BKE_object_material_slot_remove(bmain, ob)) {
     /* pass */
   }
 
   /* now we have the right number of slots */
-  for (i = 0; i < totcol; i++) {
-    BKE_object_material_assign(bmain, ob, (*matar)[i], i + 1, BKE_MAT_ASSIGN_USERPREF);
+  for (int i = 0; i < totcol; i++) {
+    if (to_object_only && ob->matbits[i] == 0) {
+      /* If we only assign to object, and that slot uses obdata material, do nothing. */
+      continue;
+    }
+    BKE_object_material_assign(bmain,
+                               ob,
+                               (*matar)[i],
+                               i + 1,
+                               to_object_only ? BKE_MAT_ASSIGN_OBJECT : BKE_MAT_ASSIGN_USERPREF);
   }
 
   if (actcol_orig > ob->totcol) {
@@ -1272,8 +1280,6 @@ void BKE_texpaint_slot_refresh_cache(Scene *scene, Material *ma)
   if (ma->paint_clone_slot >= count) {
     ma->paint_clone_slot = count - 1;
   }
-
-  return;
 }
 
 void BKE_texpaint_slots_refresh_object(Scene *scene, struct Object *ob)
@@ -1712,6 +1718,29 @@ static void material_default_volume_init(Material *ma)
   nodeSetActive(ntree, output);
 }
 
+static void material_default_holdout_init(Material *ma)
+{
+  bNodeTree *ntree = ntreeAddTree(NULL, "Shader Nodetree", ntreeType_Shader->idname);
+  ma->nodetree = ntree;
+  ma->use_nodes = true;
+
+  bNode *holdout = nodeAddStaticNode(NULL, ntree, SH_NODE_HOLDOUT);
+  bNode *output = nodeAddStaticNode(NULL, ntree, SH_NODE_OUTPUT_MATERIAL);
+
+  nodeAddLink(ntree,
+              holdout,
+              nodeFindSocket(holdout, SOCK_OUT, "Holdout"),
+              output,
+              nodeFindSocket(output, SOCK_IN, "Surface"));
+
+  holdout->locx = 10.0f;
+  holdout->locy = 300.0f;
+  output->locx = 300.0f;
+  output->locy = 300.0f;
+
+  nodeSetActive(ntree, output);
+}
+
 Material *BKE_material_default_empty(void)
 {
   return &default_material_empty;
@@ -1757,6 +1786,7 @@ void BKE_materials_init(void)
 
   material_default_surface_init(&default_material_surface);
   material_default_volume_init(&default_material_volume);
+  material_default_holdout_init(&default_material_holdout);
   material_default_gpencil_init(&default_material_gpencil);
 }