Orkuncakilkaya
c5e58d14ea
The DEM (R16 with mips, 44 MB) was read only by terrain_generate and kept for the map's life; a world swap loads its own again. The height-field sun shadow was one RGBA32F for three values and an unused fourth: the lowest lit height stays 32-bit (a receiver 3000 m up compares against it to a quarter metre), the occluder distance and the cloud mask go beside it in RG16F (64 -> 32 MB), baked in a pass of their own (TS_AUX): a pipeline takes one colour format for all its targets, and drawn together into R32F + RG16F the writes went nowhere and nothing was lit. -75 MB at every fog level, off included (2008 -> 1933 MB at the overlook); the fog-off frame is unchanged (0 pixels over 8). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
43 lines
1.9 KiB
GLSL
43 lines
1.9 KiB
GLSL
// Height-field sun shadow, baked once per sun direction (the sun is fixed per scene).
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//
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// For every height-map texel: the lowest height at which a point above that texel still
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// sees the sun. A point (xz, y) is lit iff the ray toward the sun clears the ground
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// everywhere along it, i.e. y > h(xz + d.xz t) - d.y t for all t — so the value stored
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// is the maximum of that expression over the ray. Every receiver in the scene (ground,
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// trunk, crown, card, water) compares its own height against it: one march per texel,
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// once, instead of 28 taps per terrain pixel per frame, and vegetation standing in a
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// hillside's shadow goes dark with the hillside instead of glowing in front of it.
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// The second channel is the distance to the occluder that set the bound, which widens
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// the penumbra the way a real shadow softens with distance from its caster.
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in vec2 v_uv;
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out vec4 o; // TS_AUX: the occluder distance and the cloud mask (RG16F); else the lowest lit height (R32F)
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uniform sampler2D u_height;
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uniform float u_half;
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uniform vec3 u_sun;
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void main() {
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vec2 xz = (v_uv - 0.5) * 2.0 * u_half;
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vec3 d = u_sun;
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float lit = -1.0e6;
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float at = 0.0;
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if (d.y > 0.02) {
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float t = 1.5, step = 1.5;
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for (int i = 0; i < 128; i++) {
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vec2 q = xz + d.xz * t;
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vec2 uv = q / (2.0 * u_half) + 0.5;
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if (uv.x < 0.0 || uv.x > 1.0 || uv.y < 0.0 || uv.y > 1.0) break;
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float h = texture(u_height, uv).r - d.y * t;
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if (h > lit) { lit = h; at = t; }
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t += step;
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step *= 1.045;
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}
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}
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// the cloud layer's mask, once, into the aux target's G: sampled by cloudShadow() with the sun offset and
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// the drift applied as a uv shift, instead of a five-octave fbm in every lit pixel of
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// every pass
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float cloud = smoothstep(0.02, 0.32, fbm(xz * 0.0011, 5));
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#ifdef TS_AUX
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o = vec4(at, cloud, 0.0, 1.0);
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#else
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o = vec4(lit, 0.0, 0.0, 1.0);
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#endif
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}
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