The new ray length node in Blender 2.64 allows to fake absorption even without a volumetric shader. This tutorial shows you how to create your own absorption shader and make it re-usable.
Have you ever seen a complex Cycles shader that uses some strange math nodes to create cool features you'd like to play with? Ever tried to get your head around it and ended up with a headache? This tutorial shows you how you can create a Cycles shader node tree from a physical formula. In the end you'll be able to understand other people's setups a lot better and be able to create your own re-usable shaders from physical formulas you can find in textbooks or on the internet.
- 00:00 - 02:40 Intro and Overview
- 02:40 - 10:05 How Cycles handles light and an analysis of Beer's law.
- 10:05 - 17:00 Translating the formula to a Cycles shader.
- 17:00 - 22:50 Walkthrough of the possibilities and creating a group node for easy re-use.
- 22:50 - 25:50 Notes on Light Paths and Bounces in Cycles.
Download the training Blendfile including the finished shader here!
Further reading: An approximate SSS-setup using the ray length node (thx blazraidr) and a set of node-groups that are based on real-world absorption coefficients (thx Broadstu).