1. The video memory that holds the pixels from which the video display (frame) is refreshed.
2. In mental ray, rendering attributes (color, alpha, depth, and so on) that control which image channels are passed to the shader and in what format.

For example, a 2D blur output shader might require 8-bit color, floating-point alpha, and motion vector.

Beginning Maya 2009, user framebuffers are deprecated and multi-render passes should be used instead.

• mentalrayUserBuffer node attributes