Screen Shot 2014-05-10 at 8.56.40 AMSparrowhawke3D has announced a new plugin for Carrara, the Instance Randomizer a shader which generates a random value between 0 and 100. With many instances of the shader in a scene, the results for each will be different. The shader can be used to drive a color gradient as shown in the documentation. With Boolean enabled the shader returns 0 or 100 – making either/or decisions possible.

The plugin will not drive instances in Carrara’s Replicator, only real instances.

Instance Randomizer is free at Sparrowhawke’s website, and is for Carrara 5 to 8.5 on Windows, and Carrara 8 to 8.5 on Mac.
http://www.sparrowhawke3d.com/InstanceRandomizerPage.html