2 files changed, 32 insertions, 13 deletions

diff --git a/source/blender/nodes/composite/node_composite_tree.cc b/source/blender/nodes/composite/node_composite_tree.cc
index c54382cc1ad..08dbd4ad6f0 100644
--- a/source/blender/nodes/composite/node_composite_tree.cc
+++ b/source/blender/nodes/composite/node_composite_tree.cc
@@ -249,6 +249,23 @@ void ntreeCompositUpdateRLayers(bNodeTree *ntree)
   }
 }
 
+void ntreeCompositRegisterPass(bNodeTree *ntree,
+                               Scene *scene,
+                               ViewLayer *view_layer,
+                               const char *name,
+                               eNodeSocketDatatype type)
+{
+  if (ntree == nullptr) {
+    return;
+  }
+
+  LISTBASE_FOREACH (bNode *, node, &ntree->nodes) {
+    if (node->type == CMP_NODE_R_LAYERS) {
+      node_cmp_rlayers_register_pass(ntree, node, scene, view_layer, name, type);
+    }
+  }
+}
+
 void ntreeCompositTagRender(Scene *scene)
 {
   /* XXX Think using G_MAIN here is valid, since you want to update current file's scene nodes,
diff --git a/source/blender/nodes/composite/nodes/node_composite_image.cc b/source/blender/nodes/composite/nodes/node_composite_image.cc
index f2b9fbc2215..6f4f9d7e597 100644
--- a/source/blender/nodes/composite/nodes/node_composite_image.cc
+++ b/source/blender/nodes/composite/nodes/node_composite_image.cc
@@ -269,12 +269,7 @@ void node_cmp_rlayers_register_pass(bNodeTree *ntree,
   }
 }
 
-struct CreateOutputUserData {
-  bNodeTree &ntree;
-  bNode &node;
-};
-
-static void cmp_node_rlayer_create_outputs_cb(void *userdata,
+static void cmp_node_rlayer_create_outputs_cb(void *UNUSED(userdata),
                                               Scene *scene,
                                               ViewLayer *view_layer,
                                               const char *name,
@@ -282,8 +277,18 @@ static void cmp_node_rlayer_create_outputs_cb(void *userdata,
                                               const char *UNUSED(chanid),
                                               eNodeSocketDatatype type)
 {
-  CreateOutputUserData &data = *(CreateOutputUserData *)userdata;
-  node_cmp_rlayers_register_pass(&data.ntree, &data.node, scene, view_layer, name, type);
+  /* Register the pass in all scenes that have a render layer node for this layer.
+   * Since multiple scenes can be used in the compositor, the code must loop over all scenes
+   * and check whether their nodetree has a node that needs to be updated. */
+  /* NOTE: using G_MAIN seems valid here,
+   * unless we want to register that for every other temp Main we could generate??? */
+  ntreeCompositRegisterPass(scene->nodetree, scene, view_layer, name, type);
+
+  for (Scene *sce = (Scene *)G_MAIN->scenes.first; sce; sce = (Scene *)sce->id.next) {
+    if (sce->nodetree && sce != scene) {
+      ntreeCompositRegisterPass(sce->nodetree, scene, view_layer, name, type);
+    }
+  }
 }
 
 static void cmp_node_rlayer_create_outputs(bNodeTree *ntree,
@@ -303,17 +308,14 @@ static void cmp_node_rlayer_create_outputs(bNodeTree *ntree,
         data->prev_index = -1;
         node->storage = data;
 
-        CreateOutputUserData userdata = {*ntree, *node};
-
         RenderEngine *engine = RE_engine_create(engine_type);
         RE_engine_update_render_passes(
-            engine, scene, view_layer, cmp_node_rlayer_create_outputs_cb, &userdata);
+            engine, scene, view_layer, cmp_node_rlayer_create_outputs_cb, nullptr);
         RE_engine_free(engine);
 
         if ((scene->r.mode & R_EDGE_FRS) &&
             (view_layer->freestyle_config.flags & FREESTYLE_AS_RENDER_PASS)) {
-          node_cmp_rlayers_register_pass(
-              ntree, node, scene, view_layer, RE_PASSNAME_FREESTYLE, SOCK_RGBA);
+          ntreeCompositRegisterPass(ntree, scene, view_layer, RE_PASSNAME_FREESTYLE, SOCK_RGBA);
         }
 
         MEM_freeN(data);