This page gives information on the Wire Color Render Channel.
Overview
The Wire Color Render channel stores the wireframe color of the object as set in the scene. The color is flat, with no highlights or shadows. This render element can be used to generate masks for objects for use in compositing.
Use VRayWireColor when you wish to separate objects by wireframe color rather than by Object ID or Material ID.
UI Path
||Node Editor|| > Add > Render Channels > Color Channel > Wire Color
Common Uses
The Wire Color Render Channel is commonly used to create a mask for objects in a scene for color correction or color grading. In the example below, a matte was created for the floor and then used to change the color of the floor by using color correction in composite.
Wire Color Render Element
Matte generated from purple wire color
Original Beauty composite
Color correction of floor using matte