Developing a Custom Shader

Most visual effects in Lumberyard are produced by shaders, which employ a number of standard and advanced lighting models like Blinn, Cook-Torrance, Oren-Naye, Kajiya-Kay, and some custom models.

There are two types of shaders used: lighting shaders that interact with scene illumination, and regular shaders that don’t calculate any lighting information and are used for post-processing effects. All lighting shaders have a common structure and make use of a unified shading interface. This interface should always be used to ensure proper usage of the lighting pipeline, minimize code duplication and save a lot of work.

Lumberyard uses an ubershader system with compile-time defines to handle the many different shader permutations that are required for combining numerous shader features. The shader format used that is very similar to High-Level Shader Language (HLSL), DirectX FX, and CgFX.

Shader development is a programming discipline onto itself and requires expert knowledge to optimize as shader code can be performance-critical and platform-dependent.

The easiest way to create new shaders is with a text editor.

To create a new shader

1. Using a text editor, copy an existing .ext extension file and associated .cfx effect file.

2. Add the shader’s file name to the lumberyard_version/dev/Editor/Materials/ShaderList.xml file.

3. Restart the Material Editor. The new shader appears and you can assign it to a material.

Topics

• Shader Development Best Practices
• Shader Rendering Pipeline
• Hot Reloading of Shaders
• Remote Shader Compiler
• Generating Shader Combinations