Attention
Unity has discontinued selling and supporting Deep Compositing effective February 7, 2024.
About Deep Compositing
What is deep alpha compositing?
Deep alpha compositing is a way of rendering multiple CG elements separately, and then combining them without using traditional holdouts, and without loss of quality. The system calculates pixel visibility while compositing (instead of rendering).
This means artists can work on separate parts of the same shot completely independently, which helps make CG production faster, more flexible, and less error-prone.
Deep compositing relies on deep data, which the renderer outputs alongside the image, and you pass around in Nuke (using plugins).
What does it include?
Deep alpha compositing uses:
- Deep OpenEXR (EXR) files - an OpenEXR extension (since 2.x), based on Wētā's original ODZ file format.
Most professional 3D renderers can render deep EXR files (RenderMan, Arnold, VRay, RedShift, etc).
- deep alpha - lists of alpha samples, at increasing depths, for all objects covered by each pixel in an image
- deep color — alpha maps with color, providing depth-sorted lists of Z,R,G,B,A values per pixel
- wnkDeep — a Nuke plugin to load and manipulate alpha and color maps, including nodes that:
- read and write EXR files
- convert between deep alpha maps and images
- merge deep alpha maps, to create a single combined map
- perform clipping on samples by depth
- combine deep alpha maps with RGB images, to create deep color maps
- create fog volumes |
- apply depth-of-field blur (defocus) using an alpha map as the depth channel
- keymix (selective blending) between two alpha maps
- reformat to different resolution, with lossy or lossless filtering
- arbitrary 2D transformation (translate, rotate, and sheer), with lossy or lossless filtering
- expression-based manipulation of sample values (such as conditionally adding values to depth)
- convert deep data to geometry.
- an interface for building scripts to automate deep workflows — assembling series of nodes for deep compositing, producing a satisfactory rendered image without tweaking.
Refer to the following topics:
- Deep compositing's development
- How Deep Comp works (with examples)
- typical workflows
For the list of Deep Comp Nuke nodes, refer to Deep Nodes.
For a comparison between Nuke (Foundry) Deep nodes and Unity Deep Comp nodes, refer to Comparison to Foundry Nodes.