optimize frame_change_pre handler

handlers/frame_change_pre.py

@@ -4,47 +4,33 @@
 from ..utils import openVDB_sequence_resolve_all
 from ..utils import clamp
 
-# Flag that saves us from having to iterate all node trees when no image sequences are used (the common case).
-# Set in image node export method, reset when new .blend is loaded in load_post.
-using_image_sequences = False
-
-# Flag that saves us from having to iterate all node trees when no image sequences are used (the common case).
-# Set in openVDB node export method, reset when new .blend is loaded in load_post.
-using_smoke_sequences = False
+RELEVANT_NODES = {"LuxCoreNodeTexImagemap", "LuxCoreNodeTexOpenVDB", "LuxCoreNodeTexTimeInfo"}
 
+# Flags that save us from having to iterate all node trees when no related nodes are used (the common case).
+# Set in relevant node export methods, reset when new .blend is loaded in load_post.
+have_to_check_node_trees = False
 
+# Important: Since this function is executed on every frame, even milliseconds of processin time in here will
+# bring down the frame rate of animations considerably. Always assume the worst case: A big scene with many
+# materials and complex node trees, and optimize for it.
 @persistent
 def handler(scene):
-    global using_image_sequences
-    global using_smoke_sequences
+    global have_to_check_node_trees
 
-    if not (using_image_sequences or using_smoke_sequences) or scene.render.engine != "LUXCORE":
+    if not have_to_check_node_trees or scene.render.engine != "LUXCORE":
         return
 
-    found_image_sequence = False
-    found_smoke_sequence = False
+    found_relevant_node = False
     for mat in bpy.data.materials:
         if not mat.luxcore.node_tree:
             continue
 
-        if (utils_node.has_nodes(mat.luxcore.node_tree, "LuxCoreNodeTexOpenVDB", True) or
-                utils_node.has_nodes(mat.luxcore.node_tree, "LuxCoreNodeTexSmoke", True)):
-            found_smoke_sequence = True
-            for node in mat.luxcore.node_tree.nodes:
-                if node.bl_idname == "LuxCoreNodeMatOutput" and node.active:
-                    # Force a viewport update
-                    mat.luxcore.node_tree.links.new(node.inputs["Material"], node.inputs["Material"].links[0].from_socket)
-                    break
-
-        for node in utils_node.find_nodes(mat.luxcore.node_tree, "LuxCoreNodeTexImagemap", True) or \
-                utils_node.find_nodes(mat.luxcore.node_tree, "LuxCoreNodeTexTimeInfo", True):
-            found_image_sequence = True
+        if utils_node.has_nodes_multi(mat.luxcore.node_tree, RELEVANT_NODES, True):
+            found_relevant_node = True
             # Force a viewport update
             mat.diffuse_color = mat.diffuse_color
-            break
 
-    using_image_sequences = found_image_sequence
-    using_smoke_sequences = found_smoke_sequence
+    have_to_check_node_trees = found_relevant_node
 
     # TODO we are not handling area lights with image sequence textures right now
     #  because I can't think of a check with good performance in large scenes.

handlers/load_post.py

@@ -58,5 +58,5 @@ def handler(_):
     # Run converters for backwards compatibility
     compatibility.run()
 
-    frame_change_pre.using_image_sequences = False
+    frame_change_pre.have_to_check_node_trees = False
     LuxCoreErrorLog.clear()

nodes/textures/imagemap.py

@@ -182,7 +182,7 @@ def sub_export(self, exporter, depsgraph, props, luxcore_name=None, output_socke
                 return [0, 0, 0]
 
         if self.image.source == "SEQUENCE":
-            frame_change_pre.using_image_sequences = True
+            frame_change_pre.have_to_check_node_trees = True
 
         try:
             filepath = ImageExporter.export(self.image, self.image_user, exporter.scene)

nodes/textures/openVDB.py

@@ -296,13 +296,13 @@ def sub_export(self, exporter, depsgraph, props, luxcore_name=None, output_socke
 
                 file_path = self.get_cachefile_name(domain_eval, utils.clamp(frame, frame_start, frame_end), 0)
                 if frame_end > frame_start:
-                    frame_change_pre.using_smoke_sequences = True
+                    frame_change_pre.have_to_check_node_trees = True
         else:
             indexed_filepaths = utils.openVDB_sequence_resolve_all(self.file_path)
             if len(indexed_filepaths) > 1:
                 index, file_path = indexed_filepaths[utils.clamp(frame, self.first_frame, self.last_frame)-1]
                 if self.last_frame > self.first_frame:
-                    frame_change_pre.using_smoke_sequences = True
+                    frame_change_pre.have_to_check_node_trees = True
 
         #Get transformation of domain bounding box, local center is lower bounding box corner
         scale = domain_eval.dimensions

nodes/textures/smoke.py

@@ -9,7 +9,6 @@
 from ...utils import node as utils_node
 from ...ui import icons
 from ...utils.errorlog import LuxCoreErrorLog
-from ...handlers import frame_change_pre
 
 class LuxCoreNodeTexSmoke(bpy.types.Node, LuxCoreNodeTexture):
     bl_label = "Smoke"
@@ -76,7 +75,6 @@ def sub_export(self, exporter, depsgraph, props, luxcore_name=None, output_socke
             }
             return self.create_props(props, definitions, luxcore_name)
 
-        frame_change_pre.using_smoke_sequences = True
         domain_eval = self.domain.evaluated_get(depsgraph)
 
         scale = domain_eval.dimensions

nodes/textures/timeinfo.py

@@ -28,7 +28,7 @@ def draw_buttons(self, context, layout):
 
     def sub_export(self, exporter, depsgraph, props, luxcore_name=None, output_socket=None):
         scene = depsgraph.scene_eval
-        frame_change_pre.using_image_sequences = True
+        frame_change_pre.have_to_check_node_trees = True
 
         definitions = {
             "type": "constfloat1",

utils/node.py

@@ -163,6 +163,26 @@ def has_nodes(node_tree, bl_idname, follow_pointers):
     return False
 
 
+def has_nodes_multi(node_tree, bl_idname_set, follow_pointers):
+    for node in node_tree.nodes:
+        if follow_pointers and node.bl_idname == "LuxCoreNodeTreePointer" and node.node_tree:
+            try:
+                if has_nodes_multi(node.node_tree, bl_idname_set, follow_pointers):
+                    return True
+            except RecursionError:
+                msg = (f'Pointer nodes in node trees "{node_tree.name}" and "{node.node_tree.name}" '
+                       "create a dependency cycle! Delete one of them.")
+                LuxCoreErrorLog.add_error(msg)
+                # Mark the faulty nodes in red
+                node.use_custom_color = True
+                node.color = (0.9, 0, 0)
+                return False
+        if node.bl_idname in bl_idname_set:
+            return True
+
+    return False
+
+
 def force_viewport_update(_, context):
     """
     Since Blender 2.80, properties on custom sockets and custom nodes are not listed