#define CAMERA_DISTANCE 2.4 #define CAMERA_SPIN_SPEED 0.13 #define FOV_MULTIPLIER 0.8 #define SUN_DIR normalize(vec3(1,0.8,0)) #define SUN_COLOR vec3(2,1.6,0.9)*2.3 #define SCATTERING_MULTIPLIER 0.0 #define CLOUD_SIZE vec3(2.6,1.1,2.6) vec3 aces_tonemap(vec3 color){ mat3 m1 = mat3( 0.59719, 0.07600, 0.02840, 0.35458, 0.90834, 0.13383, 0.04823, 0.01566, 0.83777 ); mat3 m2 = mat3( 1.60475, -0.10208, -0.00327, -0.53108, 1.10813, -0.07276, -0.07367, -0.00605, 1.07602 ); vec3 v = m1 * color; vec3 a = v * (v + 0.0245786) - 0.000090537; vec3 b = v * (0.983729 * v + 0.4329510) + 0.238081; return pow(clamp(m2 * (a / b), 0.0, 1.0), vec3(1.0 / 2.2)); } float rayPlaneIntersect(vec3 ro, vec3 rd, vec3 center, vec3 normal) { float denom = dot(normal, rd); if (abs(denom) > 0.0001f) // your favorite epsilon { float t = dot(center - ro, normal) / denom; return t; // you might want to allow an epsilon here too } return -1.; } float opSmoothUnion( float d1, float d2, float k ) { float h = clamp( 0.5 + 0.5*(d2-d1)/k, 0.0, 1.0 ); return mix( d2, d1, h ) - k*h*(1.0-h); } float noise( in vec3 x ) { vec3 i = floor(x); vec3 f = fract(x); f = f*f*(3.0-2.0*f); vec2 uv = (i.xy+vec2(37.0,17.0)*i.z) + f.xy; vec2 rg = textureLod( iChannel1, (uv+0.5)/256.0, 0.0).yx; return mix( rg.x, rg.y, f.z )*2.-1.; } vec3 skyColor(vec3 viewDir, vec3 camPos) { float horizonNoise = smoothstep(-0.2, 0.9, noise(viewDir * vec3(8,36,8))+noise(viewDir * vec3(28,56,28))*0.5); float skyExtinction1 = exp(-max(0., abs(viewDir.y)*28. - horizonNoise*1.8)); float skyExtinction2 = exp(-max(0., abs(viewDir.y)*12. - horizonNoise*0.5)); vec3 sky = vec3(7.5, 7.2, 7.2) * mix(vec3(0.12, 0.85, 1.0) * 1.0, vec3(1), skyExtinction1) * mix(vec3(0.5, 0.25, 0.52) * 0.5, vec3(1), skyExtinction2); sky += vec3(3, 2, 0.5) * pow(clamp(dot(viewDir, SUN_DIR), 0., 1.), 4.); sky += vec3(50, 40, 2) * smoothstep(0.991, 0.997, dot(viewDir, SUN_DIR)) * 0.3; float groundD = rayPlaneIntersect(camPos, viewDir, vec3(0,-50,0), vec3(0,1,0)); vec3 groundPoint = camPos + viewDir * groundD; float groundNoise = smoothstep(-0.5, 0.5, noise(groundPoint*0.07)*0.99 + noise(groundPoint*0.69)*0.3); vec3 groundColPre = mix(vec3(0.3, 0.4, 0.6), vec3(0.45, 0.62, 0.68), groundNoise); vec3 groundCol = mix(groundColPre, vec3(0.79, 1.28, 1.85), 1.-exp(-max(groundD,0.)*0.003)); vec3 ground = groundCol * ((1.0-pow(abs(viewDir.y),0.5))*0.8+0.2); return mix(ground, sky, smoothstep(-0.04, 0.1, viewDir.y))*0.65; } vec3 ambientContribution(vec3 normal) { vec3 ground = vec3(0.36, 0.6, 0.65)*0.4; //ground *= smoothstep(-1., 0., normal.y)*0.5+0.5; return mix(ground, vec3(0.4,0.8,1.1), pow(smoothstep(-1., 1., normal.y),1.0)); } float density(vec3 pos) { vec3 normDist = pos / (CLOUD_SIZE*0.5); float topClip = smoothstep(-0.0, 1., normDist.y); float sideClipX = smoothstep(0.60-topClip*0.6, 1., abs(normDist.x)); float sideClipZ = smoothstep(0.60-topClip*0.6, 1., abs(normDist.z)); float bottomClip = smoothstep(-0.5, -1.0, normDist.y); float freq = 3.9; float sum = 0.; float amp = 0.5; float d1 = distance(normDist * vec3(1.0,0.9,1.0), vec3(0, -0.65, 0) * vec3(1.0,0.8,1.0)); float d2 = distance(normDist * vec3(1.6,1.0,1.6), vec3(-0.3, 0.2, 0.3)); float dens = 1.-opSmoothUnion( pow(d1*1.1, 1.2), pow(d2*1.1, 1.4), 0.5 ); pos += vec3(1,0,2); for (int i = 1; i<4; i++) { float timeOffs = iTime * (1.+float(i)*1.0)*0.4; if (i==1) timeOffs = 0.; vec3 sineCoeff = vec3( pos.z*2.4*freq, pos.x*2.6*freq + timeOffs, pos.y*2.8*freq ); vec3 randOffs = sin(sineCoeff); dens += (abs(noise(pos * freq + vec3(i)*167. + randOffs*0.022*freq))-0.48) * amp; freq *= 2.1; amp *= 0.5; } return max(0., 0.0 + dens*0.8 - pow(sideClipX,10.5)*0.4 - pow(sideClipZ, 10.5)*0.4 - pow(topClip,13.5)*0.3 - pow(bottomClip,25.)*0.5 ); } float blueNoise(vec2 pixelPos) { const float c_goldenRatioConjugate = 0.61803398875f; // also just fract(goldenRatio) float val = textureLod(iChannel0, pixelPos / 1024.0f, 0.).r; int frame = iFrame % 64; val = fract(val + float(frame) * c_goldenRatioConjugate); return val; } vec2 intersectAABB(vec3 rayOrigin, vec3 rayDir, vec3 boxMin, vec3 boxMax) { vec3 tMin = (boxMin - rayOrigin) / rayDir; vec3 tMax = (boxMax - rayOrigin) / rayDir; vec3 t1 = min(tMin, tMax); vec3 t2 = max(tMin, tMax); float tNear = max(max(t1.x, t1.y), t1.z); float tFar = min(min(t2.x, t2.y), t2.z); return vec2(tNear, tFar); } void mainImage( out vec4 fragColor, in vec2 fragCoord ) { // Normalized pixel coordinates (from -1 to 1) vec2 uv = (fragCoord - 0.5*iResolution.xy) / iResolution.y; float camX = cos(iTime*CAMERA_SPIN_SPEED+2.0); float camZ = sin(iTime*CAMERA_SPIN_SPEED+2.0); float camYOffs = sin(iTime*0.3)*0.28; vec3 cameraPos = normalize(vec3(camX,camYOffs-0.03,camZ))*CAMERA_DISTANCE; vec3 cameraDir = -normalize(cameraPos+vec3(0.,cameraPos.y*0.30+0.11,0.)); vec3 cameraRight = normalize(cross(vec3(0,1,0), cameraDir)); vec3 cameraUp = normalize(cross(cameraDir, cameraRight)); vec3 viewDir = normalize(cameraDir + cameraUp*uv.y*FOV_MULTIPLIER + cameraRight*uv.x*FOV_MULTIPLIER); float ao = 1.0; vec3 final = skyColor(viewDir, cameraPos); vec3 sunUp = normalize(cross(SUN_DIR, vec3(0,1,0))); vec3 sunRight = normalize(cross(SUN_DIR, sunUp)); sunUp = normalize(cross(SUN_DIR, sunRight)); vec2 box = intersectAABB(cameraPos, viewDir, -CLOUD_SIZE*0.5, CLOUD_SIZE*0.5); vec3 hitPoint = cameraPos + viewDir*box.x; if (box.x<=box.y) { float lightDirMult = 0.9 + blueNoise(fragCoord+50.)*0.2; hitPoint += viewDir * blueNoise(fragCoord+123.) * 0.2; //lightDirMult = 1.; vec4 volume = vec4(0); const float marchStep = 0.07; for(int i = 0; i<32; i++) { vec3 p = hitPoint + viewDir*float(i)*marchStep; if (distance(p, cameraPos)>box.y) break; float dens = density(p); float light = 0.0; vec3 lightP = p; float lightStepInc = 2.0; float lightStep = 0.002; for (int n = 0; n<8; n++) { float lightDens = density(lightP); light += lightDens * lightStep * 20.; float randUp = (blueNoise(fragCoord + vec2(n)*50.)*2.-1.) * SCATTERING_MULTIPLIER; float randRight = (blueNoise(fragCoord + vec2(n)*88.)*2.-1.) * SCATTERING_MULTIPLIER; vec3 scatterVec = normalize(SUN_DIR + sunUp*randUp + sunRight*randRight); lightP += scatterVec * lightStep * lightDirMult; if ( abs(lightP.y)>CLOUD_SIZE.y*0.5 || abs(lightP.x)>CLOUD_SIZE.x*0.5 || abs(lightP.z)>CLOUD_SIZE.z*0.5 ) break; lightStep *= lightStepInc; } light = exp(-light*light*12.0); //Ambient /**/ float amb = 0.; for (int a = 1; a<2; a++) { vec3 ambP = p + normalize(vec3( blueNoise(fragCoord + vec2(a) * 120.)*2.0-1.0, blueNoise(fragCoord + vec2(a) * 151.)*2.0-1.0, blueNoise(fragCoord + vec2(a) * 199.)*2.0-1.0 ))*0.10*(1.+float(a)*0.4); amb += density(ambP); } float ambSoft = exp(-amb*5.0)*0.9+0.1; vec3 ambient = mix(vec3(0.15, 0.25,0.55), vec3(0.58,0.85,1.02), ambSoft); amb = 0.; for (int a = 1; a<2; a++) { vec3 ambP = p + normalize(vec3( blueNoise(fragCoord + vec2(a) * 150.)*2.0-1.0, blueNoise(fragCoord + vec2(a) * 81.)*2.0-1.0, blueNoise(fragCoord + vec2(a) * 149.)*2.0-1.0 ))*0.05*(1.+float(a)*0.4); amb += density(ambP); } ambient *= exp(-amb*3.0)*0.8+0.2; vec3 newColor = vec3(0.7, 0.85, 1) * (light * SUN_COLOR + ambient*1.6); volume.rgb += (1.0 - volume.a) * dens * newColor; volume.a += (1.0 - volume.a) * dens; } if (volume.a > 0.001) volume.rgb /= volume.a; final = mix(final, volume.rgb, clamp(volume.a*1.3, 0., 1.)); } // Output to screen uv.y *= 1.6; float vignette = exp2(-length(uv*uv*uv*uv*0.6)); fragColor = vec4(aces_tonemap(final) * vignette,1.0); }