Black Hole

Raymarched gravitational lensing — null geodesics bend starlight around an event horizon while a Keplerian accretion disk glows with Doppler beaming, graded through an HDR bloom chain.

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index.tsx renderer.ts black-hole.wgsl bright-pass.wgsl blur.wgsl composite.wgsl

struct Blur {
  texelSize: vec2f,
  direction: vec2f,
  radius: f32,
}
 
@group(0) @binding(0) var src: texture_2d<f32>;
@group(0) @binding(1) var samp: sampler;
@group(0) @binding(2) var<uniform> blur: Blur;
 
@fragment fn fs_main(@location(0) uv: vec2f) -> @location(0) vec4f {
  // 9-tap Gaussian weights.
  var weights = array<f32, 5>(0.227027, 0.1945946, 0.1216216, 0.054054, 0.016216);
  let step = blur.texelSize * blur.direction * blur.radius;
  var result = textureSampleLevel(src, samp, uv, 0.0).rgb * weights[0];
  for (var i = 1; i < 5; i++) {
    let offset = step * f32(i);
    result += textureSampleLevel(src, samp, uv + offset, 0.0).rgb * weights[i];
    result += textureSampleLevel(src, samp, uv - offset, 0.0).rgb * weights[i];
  }
  return vec4f(result, 1.0);
}