Inverted occlusion in Max.

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

Installation.

• 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.

Usage.

• 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 o bitmaps to improve the result.

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