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Render Passes
In addition to the traditional passes (spec, AO, RGB masks, etc.) we will also be adjusting the colors of our lights in comp as described here. The setup for this in our background and foreground passes is slightly different, so the passes we will need for both are likewise slightly different (note that the italicized section below is parallel for both BG and FG):

Turntables:

  • lighting
  • diffuse
  • specular
  • reflection
  • refraction (for hair)
  • sss
  • GI
  • AO
  • multimattes (see the entry in the naming conventions doc)
Backgrounds: Foregrounds:
  • diffuse
  • specular
  • reflection
  • reflection filter
  • refraction
  • sss
  • GI
  • Z Depth (see the link above). Note that for the FG depth to match the BG, the FG far distance value needs to be the same as in the BG.

  • AO (see Excluding objects from AO, example #3 for details on setting up foreground AO)
  • a custom "Light select" Render Layer for all the indirect lights called "bounce" with the following passes:
    • Lighting
    • SSS
    • Specular
    • GI pass (this render layer has GI off)
    • Multimattes (these are redundant and can be disabled by creating a layer override for the used referenced" checkbox in the Render Elements tab)
  • multimattes imported with the animated characters & props (see the link above)
  • velocity (Uncheck clamp. See Motion vector passes for details
Light Selects
    Light Select in Background(BG): Render Pass

      Naming. Light select passes are named after the light: (ex: "sun"). We make one for each light, or at a minimum one light select for all direct lights (sun, light bulbs) and a second for all indirect lights (bounce and fill). For interior shots we can have one Light Select pass for each direct light, and a group for all the indirect lights. For the FG we would limit this to one group for all direct lights (see below).

      Mode. For the Static Background render Light selects should be set to "diffuse" essentially paralleling a Lighting pass (provided no SSS materials are present).

    Light Select in Foreground(FG): Render Layer

      Bugs: There are currently two problems with Light Selects:
      1. They do not work properly with shadows on a wrapper or matte property.
      2. They do not work properly with SSS.

      That is, the result of a Light Select set to "diffuse" is the same as a Total Light pass, meaning it has the SSS in the light but not in the shadow (the forward scatter). It should instead be the same as a Lighting pass and have and additional "SSS" dropdown option.

      Solution: Passes for BG & Layers for FG: Because of this we can use Light Select passes for our Static Background render (provided it does not use any SSS materials), but for our Animated Foreground renders we need to instead create Render Layers for any Light Selects.

      Compromise: Direct & Indirect Lights : Since Render Layers (as opposed to passes) add to the render time we want to minimize them. Therefore we divide the light into two types: direct and indirect. The direct light will be in the main FG render layer along with all of the passes listed above (including GI), and the indirect lights will be put in a render Layer named "bounce" with the following passes:

      • Lighting
      • SSS
      • Specular
      • GI pass (this render layer has GI off)
      • Multimattes (these are redundant and can be disabled by creating a layer override for the used referenced" checkbox in the Render Elements tab)

      This means the for the BG all the lights are broken up into individual Light Selects (categorized in the comp into indirect and direct lights, while in the FG we restrict this to 2 passes: direct and indirect, as described above.
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