internal/manager/job_compilers/scripts/single_image_render.js

@@ -189,8 +189,6 @@ render.use_compositing = True
 node_tree = bpy.context.scene.node_tree
 overscan = 16
 
-# TODO: check if the render layers node actually exists
-feed_in_input = None
 render_layers_node = None
 for node in node_tree.nodes:
     if node.type == 'R_LAYERS':
@@ -198,8 +196,9 @@ for node in node_tree.nodes:
         render_layers_node = node
         break
 for link in node_tree.links:
-    if link.from_socket == feed_in_input:
+    if feed_in_input is not None and link.from_socket == feed_in_input:
         feed_in_output = link.to_socket
+        break
 
 from os import listdir
 from os.path import isfile, join
@@ -278,7 +277,10 @@ set_alpha_node = node_tree.nodes.new('CompositorNodeSetAlpha')
 set_alpha_node.mode = 'REPLACE_ALPHA'
 node_tree.links.new(mix_adds[-1].outputs[0], set_alpha_node.inputs[0])
 node_tree.links.new(math_adds[-1].outputs[0], set_alpha_node.inputs[1])
+if feed_in_input is not None:
   node_tree.links.new(set_alpha_node.outputs[0], feed_in_output)
+else:
+  raise Exception('No Render Layers Node found. Currently only supported with a Render Layers Node in the Compositor.')
 
 node_tree.nodes.remove(render_layers_node)
 bpy.ops.render.render(write_still=True)`