Troubleshooting Missing Render Passes When Exporting To Exr
Locating Render Passes in the Node Editor
The node editor is an essential tool for inspecting and troubleshooting issues with render passes when exporting multi-layer EXR files. Here are some techniques to locate missing or problematic render passes using the node editor:
Inspect the Render Layers Node
The render layers node organizes separate render passes and compositing operations. Expand the node in the node editor to view its inputs and outputs. Verify the render layer node has a connection to the desired render pass output nodes. If a pass socket is unconnected, it indicates the pass is not being output.
Check Layer Nodes for Desired Passes
Dive into the layer nodes hooked up to the render layers node inputs. In the properties panel, navigate to the Passes section for the layer node. Enable or disable checkboxes here to turn render passes on or off for that render layer. For example, enabling the Z pass checkbox will output a depth pass from objects in that layer.
Verify Pass Output Nodes are Connected
When enabling a new render pass in a layer node, a corresponding output socket is added to the render layers node. Make sure to connect this socket to a Composite node or File Output node so the render pass is saved or composited. Unconnected pass sockets do not get rendered or output even when enabled.
Enabling Desired Passes
If certain render passes are missing from the EXR files, they can be enabled in the render layers node:
Open Properties Panel for Render Layers Node
Select the render layers node in the node editor. Open the Properties panel to access settings for controlling render passes.
Enable Checkbox for Missing Pass in Passes Section
In the Properties panel, navigate to the Passes section. Here you can enable or disable checkboxes for common passes like Normals, Shadow, Ambient Occlusion, etc. Click the checkbox for any missing passes to include them in the render.
Connect New Socket to Composite Node
When enabling a render pass, a new corresponding output socket is added to the render layers node. Connect this to a Composite node or File Output node so the render pass gets composited or saved with the others. Leaving it unconnected means it won’t save or output.
Rendering With Multiple Layers
Complex scenes may require splitting objects across several render layers to isolate passes or effects. Here are tips for rendering with multiple layers:
Set Up Additional Render Layers Nodes
Add new Render Layers nodes for each layer required. For example, create separate layer nodes for foreground characters, background environments, vehicles etc. Adjust the scene collections per layer as needed.
Assign Materials to Appropriate Layers
To isolate material passes, assign related materials to objects in specific render layers. For example, place all glass shaders in one layer and metal shaders in another. This keeps material passes separated.
Enable Desired Passes Per Layer Node
In each Render Layers node, enable only the passes needed for that set of objects. This avoids unnecessary passes cluttering the EXR files. For example, enable shadow and emission passes only for key layers.
Debugging Black Render Passes
If certain render passes appear black when output to EXR files, there are ways to troubleshoot:
Inspect Material Nodes for Emission Shaders
Black emission passes often mean emission shaders are not assigned to materials in that render layer. Double check for emission nodes in the shader editor graphs. Ensure they are applied to objects visible in the problem layer.
Check Object Visibility Per Render Layer
Objects may be hidden in particular render layers via outliner restrictions or collection settings. Any hidden objects won’t contribute to passes for that layer. Modify object visibility as needed.
Toggle Material Pass Output Endpoints
Some material nodes include options to disable certain material pass outputs. For example, principled shaders have toggles for disabling specular, subsurface, transmission etc passes. Enable outputs as required.
Outputting Multi-Layer EXRs
To output all enabled render passes for multiple layers correctly when exporting EXR files:
Set Up File Output Node after Compositing
Connect the composite node containing all required render pass inputs to a File Output node. This saves them together into the EXR containing the separate layers and passes.
Enable Multi-Layer EXR Option
In the File Output node properties panel toggle on Multi-Layer EXR saves separate render passes into one EXR file with layers. Disable to output each pass as a separate EXR image.
Set EXR Compression Options
Adjust EXR compression as needed to reduce file sizes while retaining quality. Lossless compression keeps maximum data. Consider ZIP or PIZ wavelet compression for high quality exports.
