Planet Terrain Algorithm (GLSL Shader)

The planet shape is a standard sphere (or cube) where every vertex is pushed outwards based on a math formula (simplex Noise and Fractal Brownian Motion (FBM) in the vertexShader.

Core Logic:

• Warping: Distorts the coordinate space so the terrain doesn't look too uniform.

• FBM (Fractal Noise): Layers multiple "octaves" of noise to create mountains (rough detail).

• Ridged Noise: Inverts the noise to create sharp peaks (valleys become peaks).

• Displacement: Pushes the vertex along its normal vector.

// Inside vertexShader
vec3 warpPos = sphereP * 0.5 + seedOffset;
float warp = snoise(warpPos) * warpScale;

// Offset position by warp to create "swirly" terrain
vec3 noisePos = (sphereP + vec3(warp)) * frequency + seedOffset;

// 1. Standard Soft Noise (Hills)
float n = fbm(noisePos, octaves, persistence, 2.0);

// 2. Ridged Noise (Sharp Peaks)
// abs(snoise) creates a "crease", 1.0 - abs turns it into a peak
float r = 1.0 - abs(snoise(noisePos));
r = pow(r, 3.0); // Sharpen the peak

// Mix them based on the "Ridges" slider
float finalNoise = mix(n, r, ridge);

// Apply heightmap texture if imported
float combinedHeight = mix(finalNoise, texHeight * 2.0 - 1.0, texMix);

// Push the vertex outward
vec3 finalPos = basePos + normalize(baseDir) * combinedHeight * heightScale;