UDIM workflow in Nuke / by Xuan Prada

Texture artists, matte painters and environment artists often have to deal with UDIMs in Nuke. This is a very basic template that hopefully can illustrate how we usually handle this situation.

Cons

  • Slower than using Mari. Each UDIM is treated individually.
  • No virtual texturing, slower workflow. Yes, you can use Nuke's proxies but they are not as good as virtual texturing.

Pros

  • No paint buffer dependant. Always the best resolution available.
  • Non destructive workflow, nodes!
  • Save around £1,233 on Mari's license.

Workflow

  • I'll be using this simple footage as base for my matte.
  • We need to project this in Nuke and bake it on to different UDIMs to use it later in a 3D package.
  • As geometry support I'm using this plane with 5 UDIMs.
  • In Nuke, import the geometry support and the footage.
  • Create a camera.
  • Connect the camera and footage using a Project 3D node.
  • Disable the crop option of the Project 3D node. If not the proejctions wouldn't go any further than UV range 0-1.
  • Use a UV Tile node to point to the UDIM that you need to work on.
  • Connect the img input of the UV Tile node to the geometry support.
  • Use  a UV Project node to connect the camera and the geometry support.
  • Set projection to off.
  • Import the camera of the shot.
  • Look through the camera in the 3D view and the matte should be projected on to the geometry support.
  • Connect a Scanline Render to the UV Project.
  • Set the projection model to UV.
  • In the 2D view you should see the UDIM projection that we set previously.
  • If you need to work with a different UDIM just change the UV Tile.
  • So this is the basic setup. Do whatever you need in between like projections, painting and so on to finish your matte.
  • Then export all your UDIMs individually as texture maps to be used in the 3D software.
  • Here I just rendered the UDIMs extracted from Nuke in Maya/Arnold.