WIP on shader assignment

openpype/hosts/maya/api/lib.py

@@ -1124,19 +1124,18 @@ def get_id_required_nodes(referenced_nodes=False, nodes=None):
 
 
 def get_id(node):
-    """
-    Get the `cbId` attribute of the given node
+    """Get the `cbId` attribute of the given node.
+
     Args:
         node (str): the name of the node to retrieve the attribute from
-
     Returns:
         str
 
     """
-
     if node is None:
         return
 
+    print("><?>< {}".format(node))
     sel = om.MSelectionList()
     sel.add(node)
 
@@ -2688,3 +2687,69 @@ def show_message(title, msg):
         pass
     else:
         message_window.message(title=title, message=msg, parent=parent)
+
+
+def iter_shader_edits(relationships, shader_nodes, nodes_by_id, label=None):
+    """Yield edits as a set of actions."""
+
+    attributes = relationships.get("attributes", [])
+    shader_data = relationships.get("relationships", {})
+
+    shading_engines = cmds.ls(shader_nodes, type="objectSet", long=True)
+    assert shading_engines, "Error in retrieving objectSets from reference"
+
+    # region compute lookup
+    shading_engines_by_id = defaultdict(list)
+    for shad in shading_engines:
+        shading_engines_by_id[get_id(shad)].append(shad)
+    # endregion
+
+    # region assign shading engines and other sets
+    for data in shader_data.values():
+        # collect all unique IDs of the set members
+        shader_uuid = data["uuid"]
+        member_uuids = [
+            (member["uuid"], member.get("components"))
+            for member in data["members"]]
+
+        filtered_nodes = list()
+        for _uuid, components in member_uuids:
+            nodes = nodes_by_id.get(_uuid, None)
+            if nodes is None:
+                continue
+
+            if components:
+                # Assign to the components
+                nodes = [".".join([node, components]) for node in nodes]
+
+            filtered_nodes.extend(nodes)
+
+        id_shading_engines = shading_engines_by_id[shader_uuid]
+        if not id_shading_engines:
+            log.error("{} - No shader found with cbId "
+                      "'{}'".format(label, shader_uuid))
+            continue
+        elif len(id_shading_engines) > 1:
+            log.error("{} - Skipping shader assignment. "
+                      "More than one shader found with cbId "
+                      "'{}'. (found: {})".format(label, shader_uuid,
+                                                 id_shading_engines))
+            continue
+
+        if not filtered_nodes:
+            log.warning("{} - No nodes found for shading engine "
+                        "'{}'".format(label, id_shading_engines[0]))
+            continue
+
+        yield {"action": "assign",
+               "uuid": data["uuid"],
+               "nodes": filtered_nodes,
+               "shader": id_shading_engines[0]}
+
+    for data in attributes:
+        nodes = nodes_by_id.get(data["uuid"], [])
+        attr_value = data["attributes"]
+        yield {"action": "setattr",
+               "uuid": data["uuid"],
+               "nodes": nodes,
+               "attributes": attr_value}