atmosphere-shader

# Atmosphere Shader Skill Render physically-accurate skies, sunsets, and planetary atmospheres through atmospheric scattering — Rayleigh, Mie, and Ozone models composed via raymarching in GLSL fragment shaders. Four progressive modes from flat backdrop to LUT-optimized planetary pipeline. ## Modes | Mode | Output | Complexity | |------|--------|------------| | `sky-dome` | Single-pass fragment shader, flat sky backdrop | Entry point | | `atmosphere-post` | Depth-aware post-processing effect with atmospheric fog | Intermediate | | `planet` | Spherical atmosphere shell around a mesh, logarithmic depth | Advanced | | `lut` | Transmittance + Sky View + Aerial Perspective LUTs, FBO pipeline | Production | ## Gotchas — What Claude Gets Wrong These are the highest-signal items in this skill. Every one is a concrete, reproducible failure mode. ### 1. Wrong scattering coefficients Claude invents plausible-looking but physically incorrect beta values. Use these exact constants for Earth: ```glsl const vec3 BETA_R = vec3(5.8e-3, 13.5e-3, 33.1e-3); // Rayleigh scattering (1/km) const float BETA_M_SCATTER = 21e-3; // Mie scattering const float BETA_M_EXT = 21e-3 * 1.1; // Mie extinction (scatter + absorb) const vec3 BETA_OZONE_ABS = vec3(0.65e-3, 1.881e-3, 0.085e-3); // Ozone absorption const float RAYLEIGH_SCALE_HEIGHT = 8.0; // km const float MIE_SCALE_HEIGHT = 1.2; // km const float MIE_G = 0.76; // Henyey-Gre...