Claude-Code-Game-Studios/.claude/rules/shader-code.md

paths

paths
assets/shaders/** **/*.gdshader Assets/**/*.{shader,hlsl,cginc,compute,shadergraph} Shaders/** **/*.{usf,ush}

Shader Code Standards

All shader files, in every engine, must follow these standards to maintain visual quality, performance, and cross-platform compatibility.

Naming Conventions

• File naming: [type]_[category]_[name].[ext]
  • spatial_env_water.gdshader (Godot)
  • SG_Env_Water (Unity Shader Graph)
  • M_Env_Water (Unreal Material)
• Use descriptive names that indicate the material purpose
• Prefix with the engine's shader type — Godot spatial_, canvas_, particles_, post_; Unity SG_ (Shader Graph); Unreal M_, MI_ (instance), MF_ (function)

Code Quality

• All uniforms/parameters must have descriptive names and appropriate hints
• Group related parameters (Godot: group_uniforms, Unity: [Header], Unreal: Category)
• Comment non-obvious calculations (especially math-heavy sections)
• No magic numbers — use named constants or documented uniform values
• Include authorship and purpose comment at the top of each shader file

Performance Requirements

• Document the target platform and complexity budget for each shader
• Use appropriate precision: half/mediump on mobile where full precision isn't needed
• Minimize texture samples in fragment shaders
• Avoid dynamic branching in fragment shaders — use step(), smoothstep() and mix() (Godot, GLSL) or lerp() (HLSL: Unity, Unreal)
• No texture reads inside loops
• Two-pass approach for blur effects (horizontal then vertical)

Cross-Platform

• Test shaders on minimum spec target hardware
• Provide fallback/simplified versions for lower quality tiers
• Document which render pipeline the shader targets (Forward/Deferred, URP/HDRP, Forward+/Mobile/Compatibility)
• Do not mix shaders from different render pipelines in the same directory

Variant Management

• Minimize shader variants — each variant is a separate compiled shader
• Document all keywords/variants and their purpose
• Use feature stripping where possible to reduce build size
• Log and monitor total variant count per shader