113 lines
2.9 KiB
GLSL
113 lines
2.9 KiB
GLSL
// https://www.shadertoy.com/view/4tdSWr
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const float cloudscale = 1.1;
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const float speed = 0.03;
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const float clouddark = 0.5;
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const float cloudlight = 0.3;
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const float cloudcover = 0.2;
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const float cloudalpha = 8.0;
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const float skytint = 0.5;
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const vec3 skycolour1 = vec3(0.2, 0.4, 0.6);
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const vec3 skycolour2 = vec3(0.4, 0.7, 1.0);
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const mat2 m = mat2( 1.6, 1.2, -1.2, 1.6 );
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vec2 hash( vec2 p ) {
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p = vec2(dot(p,vec2(127.1,311.7)), dot(p,vec2(269.5,183.3)));
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return -1.0 + 2.0*fract(sin(p)*43758.5453123);
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}
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float noise( in vec2 p ) {
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const float K1 = 0.366025404; // (sqrt(3)-1)/2;
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const float K2 = 0.211324865; // (3-sqrt(3))/6;
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vec2 i = floor(p + (p.x+p.y)*K1);
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vec2 a = p - i + (i.x+i.y)*K2;
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vec2 o = (a.x>a.y) ? vec2(1.0,0.0) : vec2(0.0,1.0); //vec2 of = 0.5 + 0.5*vec2(sign(a.x-a.y), sign(a.y-a.x));
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vec2 b = a - o + K2;
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vec2 c = a - 1.0 + 2.0*K2;
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vec3 h = max(0.5-vec3(dot(a,a), dot(b,b), dot(c,c) ), 0.0 );
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vec3 n = h*h*h*h*vec3( dot(a,hash(i+0.0)), dot(b,hash(i+o)), dot(c,hash(i+1.0)));
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return dot(n, vec3(70.0));
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}
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float fbm(vec2 n) {
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float total = 0.0, amplitude = 0.1;
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for (int i = 0; i < 7; i++) {
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total += noise(n) * amplitude;
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n = m * n;
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amplitude *= 0.4;
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}
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return total;
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}
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// -----------------------------------------------
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void mainImage( out vec4 fragColor, in vec2 fragCoord ) {
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vec2 p = fragCoord.xy / iResolution.xy;
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vec2 uv = p*vec2(iResolution.x/iResolution.y,1.0);
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float time = iGlobalTime * speed;
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float q = fbm(uv * cloudscale * 0.5);
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//ridged noise shape
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float r = 0.0;
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uv *= cloudscale;
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uv -= q - time;
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float weight = 0.8;
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for (int i=0; i<8; i++){
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r += abs(weight*noise( uv ));
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uv = m*uv + time;
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weight *= 0.7;
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}
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//noise shape
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float f = 0.0;
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uv = p*vec2(iResolution.x/iResolution.y,1.0);
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uv *= cloudscale;
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uv -= q - time;
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weight = 0.7;
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for (int i=0; i<8; i++){
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f += weight*noise( uv );
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uv = m*uv + time;
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weight *= 0.6;
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}
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f *= r + f;
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//noise colour
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float c = 0.0;
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time = iGlobalTime * speed * 2.0;
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uv = p*vec2(iResolution.x/iResolution.y,1.0);
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uv *= cloudscale*2.0;
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uv -= q - time;
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weight = 0.4;
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for (int i=0; i<7; i++){
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c += weight*noise( uv );
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uv = m*uv + time;
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weight *= 0.6;
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}
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//noise ridge colour
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float c1 = 0.0;
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time = iGlobalTime * speed * 3.0;
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uv = p*vec2(iResolution.x/iResolution.y,1.0);
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uv *= cloudscale*3.0;
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uv -= q - time;
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weight = 0.4;
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for (int i=0; i<7; i++){
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c1 += abs(weight*noise( uv ));
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uv = m*uv + time;
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weight *= 0.6;
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}
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c += c1;
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vec3 skycolour = mix(skycolour2, skycolour1, p.y);
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vec3 cloudcolour = vec3(1.1, 1.1, 0.9) * clamp((clouddark + cloudlight*c), 0.0, 1.0);
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f = cloudcover + cloudalpha*f*r;
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vec3 result = mix(skycolour, clamp(skytint * skycolour + cloudcolour, 0.0, 1.0), clamp(f + c, 0.0, 1.0));
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fragColor = vec4( result, 1.0 );
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}
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