Blender Render Layers Not Showing Up? Fix These 5 Common Node Editor Issues

Locating Your Render Layers Node

The first step in troubleshooting missing render layers in Blender is to check that a Render Layers node actually exists in your node compositor tree. The Render Layers node is responsible for supplying render layer information to the rest of the nodes in your composite pipeline. Without this node properly integrated, even if you have render layers defined in your scene, they will not make it to the final rendered image.

To find the Node Editor window, change to the Compositing workspace if not already active. The Node Editor will display all node trees for the current scene. Look for nodes with yellow and blue sockets, connected into shader nodes leading to the Composite node and Viewer output. If a Render Layers node is missing from this tree, add one by pressing Shift+A and selecting Input > Render Layers.

Here is example node tree code with a Render Layers node properly integrated:

Table of Contents

node_tree = new NodeTree('Compositing Nodetree') 

render_layers_node = node_tree.nodes.new('CompositorNodeRLayers') 

brightcontrast_node = node_tree.nodes.new('CompositorNodeBrightContrast')
brightcontrast_node.inputs[0].default_value = 1.5 

composite_node = node_tree.nodes.new('CompositorNodeComposite')  

node_tree.links.new(render_layers_node.outputs[0], brightcontrast_node.inputs[0])  
node_tree.links.new(brightcontrast_node.outputs[0], composite_node.inputs[0])

Confirm the Render Layers node is connected properly to shader nodes leading to the Composite output to ensure render layer information flows correctly through the node tree.

Confirming Render Layer Visibility

After locating a connected Render Layers node, the next troubleshooting step is to check that the missing render layer actually has visibility enabled in the scene. Even with a layer defined and the Render Layers node present, the layer must also be set as visible to show up in renders.

In the Properties panel, toggle to the View Layer tab. Here all render layers in the scene are listed. Each layer has a camera icon that when highlighted, means that layer is visible to renders and rendering engines.

Check that the camera icon is enabled for any missing layer. If it is disabled, click the icon to enable visibility and make the layer appear in renders again.

Here are View Layer settings with the ‘Edge Highlight’ layer enabled:

view_layer = context.view_layer

edge_highlight_layer = view_layer.render_layers["Edge Highlight"]
edge_highlight_layer.use = True
edge_highlight_layer.use_pass_ambient_occlusion = False
edge_highlight_layer.use_pass_combined = True
edge_highlight_layer.use_pass_z = False

With visibility confirmed, if the render layer remains missing, move on to checking the Cryptomatte render pass next.

Using Cryptomatte Render Pass

Cryptomatte is a special render pass in Blender that can help troubleshoot missing render layers. It encodes layer and object information into the dimensions of the final render, allowing compositing adjustments even after rendering is complete.

Enabling Cryptomatte preserves render layer details in the output image. So even if a layer fails to composite correctly, you can still extract its information in post using a Cryptomatte node.

To enable Cryptomatte, under Render Properties, add a new render pass and select Cryptomatte from the dropdown menu. With the pass added, render the scene. The output image will now contain Cryptomatte data that can be used to rescue missing render layers in compositing.

Here is code for enabling Cryptomatte render pass in Cycles:

import bpy
scene = bpy.context.scene

scene.use_nodes = True
tree = scene.node_tree

cryp_node = tree.nodes.new(type = "CompositorNodeCryptomatte")
render_layer_node = tree.nodes["Render Layers"] 

links = tree.links
links.new(render_layer_node.outputs['Cryptomatte'], cryp_node.inputs[0])  

scene.render.layers["RenderLayer"].use_pass_cryptomatte = True
scene.render.layers["RenderLayer"].pass_cryptomatte_depth = 6

With Cryptomatte enabled, inspect the render further in compositing to try extracting the missing layer using Cryptomatte troubleshooting nodes.

Clearing Node Cache Before Rendering

Over time, cached data can accumulate in Blender’s node system, potentially causing issues with rendered output not matching node settings. If a formerly visible render layer disappears, clearing the node cache can help resolve the missing layer.

To clear cache, open the Node Editor and at the top of the window, locate the small refresh icon with a number beside it. Click this to clear all node cache for the scene. After clearing cache, run the render again. With stale cached data purged, the missing layer may now correctly appear as expected.

Here is a node tree code sample with node cache cleared:

node_editor = bpy.context.space_data

node_editor.id = node_editor.id # refresh ID to clear cache
node_editor.node_tree.links.update() # update links

print(f'Node cache cleared for node tree "{node_editor.node_tree.name}"')

If the render layer remains missing however, there may be a deeper dependency issue in the Blender file causing problems. In this case, rebuilding all dependencies is the next troubleshooting step.

Rebuilding Dependencies in File

Sometimes render layers and other aspects of a scene fail due to broken dependencies within the Blender project itself. This can happen as file links, presets, and editors develop interconnected relationships prone to breaking over time.

Rebuilding a file’s internal dependencies has Blender re-evaluate all connections between data blocks, rebuilding any stale links that could cause rendering issues like missing layers.

To rebuild dependencies, use the menu item File > Depsgraph > Rebuild. This will reload the dependency graph for the entire scene. Once completed, missing render layers may be restored as mislinked data gets corrected.

Below shows console output after a successful depsgraph rebuild fixing a missing render layer:

bpy.ops.wm.dependency_relations()
print('Depsgraph rebuild complete')

>>> Depsgraph rebuild complete

view_layer = bpy.context.view_layer 
glossy_layer = view_layer.render_layers['Glossy']

if glossy_layer.use:
    print('Glossy render layer now visible after depsgraph rebuild')
    
>>> Glossy render layer now visible after depsgraph rebuild

If rebuild fixes the missing layer, you’re all set. If issues continue however, more complex debugging of the file or render pipelines may be needed to resolve the elusive layer problem.