34 lines
965 B
GLSL
34 lines
965 B
GLSL
vec4 mfield(vec4 uv) {
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$(code)
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return $(value);
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}
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float raymarch(vec3 ro, vec3 rd) {
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float d=0.0;
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for (int i = 0; i < 200; i++) {
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vec3 p = ro + rd*d;
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float dstep = mfield(vec4(p,0.0)).w;
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d += dstep;
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if (dstep < 0.0001) break;
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}
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return d;
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}
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vec3 normal(vec3 p) {
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float d = mfield(vec4(p,0.0)).w;
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float e = .0001;
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vec3 n = d - vec3(mfield(vec4(p-vec3(e, 0.0, 0.0),0.0)).w, mfield(vec4(p-vec3(0.0, e, 0.0),0.0)).w, mfield(vec4(p-vec3(0.0, 0.0, e),0.0)).w);
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return normalize(n);
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}
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vec4 preview_2d(vec2 uv) {
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uv -= vec2(0.5);
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vec3 p = vec3(uv, 2.0-raymarch(vec3(uv, 2.0), vec3(0.0, 0.0, -1.0)));
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vec3 n = normal(p);
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vec3 l = vec3(5.0, 5.0, 10.0);
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vec3 ld = normalize(l-p);
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float o = step(p.z, 0.001);
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float shadow = 1.0-0.75*step(raymarch(l, -ld), length(l-p)-0.01);
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float light = 0.3+0.7*dot(n, ld)*shadow;
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return vec4(mfield(vec4(p, 1.0)).xyz*light, 1.0);
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}
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