Mode
Selects the copy/remap operation.
Choose whether data moves between auxiliary and color channels or is otherwise reorganized.
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Utility / DataAdvanced
CopyAux
Auxiliary-channel routing
Copies, remaps or removes auxiliary image channels and can move data between auxiliary and color channels for technical compositing workflows.
CopyAux
DaVinci Resolve · Fusion
CopyAux is a channel-management utility for passes beyond normal RGBA, including depth, vectors, IDs and other auxiliary data carried with an image.
Overview
What CopyAux does
CopyAux is a channel-management utility for passes beyond normal RGBA, including depth, vectors, IDs and other auxiliary data carried with an image.
Mental model
Treat the image as a container with RGBA plus extra labeled data channels; CopyAux lets you move, expose, preserve or discard those extra channels.
Common uses
Expose an auxiliary pass in color channels
Copy Z or vector data between images
Remove unwanted auxiliary channels
Repackage multipass data for downstream tools
Flow anatomy
Inputs & outputs
The port structure shows how this node fits into a Fusion graph.
Input
Image containing RGBA and/or auxiliary channels.
CopyAux
Fusion node
Output
Image with auxiliary channels copied, remapped or removed.
Inspector
Important parameters
Start with these controls before reaching for more complicated workarounds.
Aux Channel
Selects the auxiliary channel to process.
Pick the exact pass or data channel needed by the downstream tool.
Out Color Depth
Controls output precision for copied channel data.
High-precision technical data may require more than 8-bit storage.
Channel Missing
Defines behavior when a requested channel does not exist.
Use a predictable fallback so missing passes do not silently corrupt the comp.
Kill Aux Channels
Removes auxiliary data after the operation.
Useful when reducing payload or preventing ambiguous downstream channel selection.
Remapping (Color to Color)
Enables remapping between color channels while auxiliary data is copied.
Practical setup
A reliable workflow
- 1
Inspect which auxiliary channels are actually present.
- 2
Choose the channel and routing mode.
- 3
Set output depth appropriate to the data.
- 4
Verify the copied result in the viewer or channel inspector.
- 5
Remove unused auxiliary channels only after confirming nothing downstream needs them.
Typical node chain
RGBA + Aux→
CopyAux→
Remapped Channels
Examples
Where this node fits in real work
Expose Z for inspection
Copy a Z pass into visible RGB channels.
Multipass ImageCopyAuxViewer
Preserve technical data
Copy auxiliary channels onto a processed beauty branch.
BeautyCopyAuxDownstream Composite
Troubleshooting
Common mistakes
Assuming an auxiliary channel exists without checking
Converting technical data to insufficient bit depth
Killing channels that a later node still needs
Production notes
Practical tips
Name CopyAux nodes after the data being routed, such as CopyAux_Z or CopyAux_Vector.
Keep auxiliary data untouched until the last stage that genuinely requires cleanup.
Related nodes