// Space Jewels. December 2014 // by David Hoskins // License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License. // https://www.shadertoy.com/view/llX3zr //-------------------------------------------------------------------------- #define SUN_COLOUR vec3(1., .9, .85) #define FOG_COLOUR vec3(0.07, 0.05, 0.05) #define MOD2 vec2(443.8975,397.2973) vec3 CSize; vec4 aStack[2]; vec4 dStack[2]; vec2 fcoord; //---------------------------------------------------------------------------------------- // From https://www.shadertoy.com/view/4djSRW float Hash(vec2 p) { p = fract(p * MOD2); p += dot(p.xy, p.yx+19.19); return fract(p.x * p.y); } //---------------------------------------------------------------------------------------- vec3 Colour( vec3 p) { float col = 0.0; float r2 = dot(p,p); for( int i=0; i < 12;i++ ) { vec3 p1= 2.0 * clamp(p, -CSize, CSize)-p; col += abs(p.z-p1.z); p = p1; r2 = dot(p,p); float k = max((1.1)/(r2), .03); p *= k; } return (0.5+0.5*sin(col*vec3(1.647,-1.0,4.9))); } //-------------------------------------------------------------------------- float Map( vec3 p ) { float scale = 1.0; for( int i=0; i < 12;i++ ) { p = 2.0*clamp(p, -CSize, CSize) - p; float r2 = dot(p,p); float k = max((1.1)/(r2), .03); p *= k; scale *= k; } float l = length(p.xy); float rxy = l - 4.0; float n = l * p.z; rxy = max(rxy, -(n) / (length(p))-.1); return (rxy) / abs(scale); } //-------------------------------------------------------------------------- float Shadow( in vec3 ro, in vec3 rd) { float res = 1.0; float t = 0.05; float h; for (int i = 0; i < 6; i++) { h = Map( ro + rd*t ); res = min(7.0*h / t, res); t += h+.01; } return max(res, 0.0); } //-------------------------------------------------------------------------- vec3 DoLighting(in vec3 mat, in vec3 pos, in vec3 normal, in vec3 eyeDir, in float d) { vec3 sunLight = normalize( vec3( 0.5, 0.2, 0.3 ) ); float sh = Shadow(pos, sunLight); // Light surface with 'sun'... vec3 col = mat * SUN_COLOUR*(max(dot(sunLight,normal), 0.0)) *sh; //col += mat * vec3(0.1, .0, .0)*(max(dot(-sunLight,normal), 0.0)); normal = reflect(eyeDir, normal); // Specular... col += pow(max(dot(sunLight, normal), 0.0), 25.0) * SUN_COLOUR * 1.5 *sh; // Abmient.. col += mat * .2 * max(normal.z, 0.0); col = mix(FOG_COLOUR,col, min(exp(-d*d*.05), 1.0)); return col; } //-------------------------------------------------------------------------- vec3 GetNormal(vec3 p, float sphereR) { vec2 eps = vec2(sphereR*.5, 0.0); return normalize( vec3( Map(p+eps.xyy) - Map(p-eps.xyy), Map(p+eps.yxy) - Map(p-eps.yxy), Map(p+eps.yyx) - Map(p-eps.yyx) ) ); } //-------------------------------------------------------------------------- float SphereRadius(in float t) { if (t< 1.4) t= (1.4-t) * 4.5; t = t*0.04; return max(t*t, 16.0/iResolution.x); } //-------------------------------------------------------------------------- float Scene(in vec3 rO, in vec3 rD) { //float t = 0.0; float t = .1 * Hash(fcoord*fract(iTime)); float alphaAcc = 0.0; vec3 p = vec3(0.0); int hits = 0; for( int j=0; j < 80; j++ ) { if (hits == 8 || alphaAcc >= 1.0 || t > 10.0) break; p = rO + t*rD; float sphereR = SphereRadius(t); float h = Map(p); // Is it within the sphere?... if( h < sphereR) { // Accumulate the alphas with the scoop of geometry from the sphere... // Think of it as an expanding ice-cream scoop flying out of the camera! float alpha = (1.0 - alphaAcc) * min(((sphereR-h) / sphereR), 1.0); // put it on the 2 stacks, alpha and distance... aStack[1].yzw = aStack[1].xyz; aStack[1].x = aStack[0].w; aStack[0].yzw = aStack[0].xyz; aStack[0].x = alpha; dStack[1].yzw = dStack[1].xyz; dStack[1].x = dStack[0].w; dStack[0].yzw = dStack[0].xyz; dStack[0].x = t; alphaAcc += alpha; hits++; } t += h*.85+t*.001; } return clamp(alphaAcc, 0.0, 1.0); } //-------------------------------------------------------------------------- vec3 PostEffects(vec3 rgb, vec2 xy) { // Gamma first... rgb = pow(rgb, vec3(0.45)); // Then... #define CONTRAST 1.3 #define SATURATION 1.3 #define BRIGHTNESS 1.2 rgb = mix(vec3(.5), mix(vec3(dot(vec3(.2125, .7154, .0721), rgb*BRIGHTNESS)), rgb*BRIGHTNESS, SATURATION), CONTRAST); // Vignette... rgb *= .5+0.5*pow(180.0*xy.x*xy.y*(1.0-xy.x)*(1.0-xy.y), 0.3 ); return clamp(rgb, 0.0, 1.0); } //-------------------------------------------------------------------------- vec3 TexCube( sampler2D sam, in vec3 p, in vec3 n ) { vec3 x = texture( sam, p.yz ).xzy; vec3 y = texture( sam, p.zx ).xyz; vec3 z = texture( sam, p.xy ).yzx; return (x*abs(n.x) + y*abs(n.y) + z*abs(n.z))/(abs(n.x)+abs(n.y)+abs(n.z)); } //-------------------------------------------------------------------------- vec3 Albedo(vec3 pos, vec3 nor) { vec3 col = TexCube(iChannel0, pos*.1, nor).zxy; col *= Colour(pos); return col; } //-------------------------------------------------------------------------- vec3 CameraPath( float t ) { vec3 p = vec3(-13.0 +3.4 * sin(t),-0.+4.5 * cos(t),-1.1+.3 * sin(2.3*t+2.0) ); return p; } //-------------------------------------------------------------------------- void mainImage( out vec4 fragColor, in vec2 fragCoord ) { fcoord = fragCoord; float m = (iMouse.x/iResolution.x)*20.0; float gTime = ((iTime+26.)*.2+m); vec2 xy = fragCoord.xy / iResolution.xy; vec2 uv = (-1.0 + 2.0 * xy) * vec2(iResolution.x/iResolution.y,1.0); // Animate... CSize = vec3(.808, .99-sin((gTime+35.0)*.5)*.3, 1.151-sin((gTime+16.0)*.78)*.3); vec3 cameraPos = CameraPath(gTime + 0.0); vec3 camTarget = vec3 (-12., .0, -2.0); vec3 cw = normalize(camTarget-cameraPos); vec3 cp = vec3(0.0, 0.0,1.0); vec3 cu = normalize(cross(cw,cp)); vec3 cv = cross(cu,cw); vec3 dir = normalize(uv.x*cu + uv.y*cv + 1.1*cw); vec3 col = vec3(.0); for (int i = 0; i <2; i++) { dStack[i] = vec4(-20.0); } float alpha = Scene(cameraPos, dir); // Render both stacks... for (int s = 0; s < 2; s++) { for (int i = 0; i < 4; i++) { float d = dStack[s][i]; if (d < 0.0) continue; float sphereR = SphereRadius(d); vec3 pos = cameraPos + dir * d; vec3 normal = GetNormal(pos, sphereR); vec3 alb = Albedo(pos, normal); col += DoLighting(alb, pos, normal, dir, d)* aStack[s][i]; } } // Fill in the rest with fog... col += FOG_COLOUR * (1.0-alpha); col = PostEffects(col, xy) * smoothstep(.0, 2.0, iTime); fragColor=vec4(col,1.0); } //--------------------------------------------------------------------------