Inverted occlusion in 3D Max / by Xuan Prada

People asked me for a step by step installation and usage of Binary Alchemy Color Ray Length shader in 3D Max.
Here we go.


  • Download BA Shaders for 3D Max.
  • Copy .dll files here -> “3ds Max 2010\mentalray\shaders_3rdparty\shaders”
  • Copy .mi files here -> “3ds Max 2010\mentalray\shaders_3rdparty\include”
  • Edit “3rdparty.mi” located here -> 3ds Max 2010\mentalray\shaders_3rdparty
  • Your “3rdparty.mi” must be something like this.


  • Create a matte/shadow shader and uncheck “receive shadows” and “use ambient occlusion”.
  • In the “camera mapped background” input, connect a “BA_color_raylength” shader.
  • Play with the “spread” to control the behaviour of the occlusion.
  • Once rendered you’ll have something similar to this.
  • Mix the “BA_color_raylength” with procedural maps or bitmaps to improve the result.

Edit: The most important parameters to play with are “spread” and “far output”.