160 lines
3.9 KiB
GLSL
160 lines
3.9 KiB
GLSL
/*
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* License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
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*
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* Created by wj just by playing with the formula of the original version
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*
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* here: https://www.shadertoy.com/view/lt2fDz created by bal-khan
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*
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* (and by adding some music..=
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*/
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precision highp float;
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uniform float time;
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uniform vec2 resolution;
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float iTime;
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vec2 iResolution;
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vec2 march(vec3 pos, vec3 dir);
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vec3 camera(vec2 uv);
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void rotate(inout vec2 v, float angle);
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float t; // time
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vec3 ret_col; // torus color
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vec3 h; // light amount
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#define I_MAX 400.
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#define E 0.00001
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#define FAR 50.
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#define PI 3.14
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// blackbody by aiekick : https://www.shadertoy.com/view/lttXDn
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// -------------blackbody----------------- //
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// return color from temperature
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//http://www.physics.sfasu.edu/astro/color/blackbody.html
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//http://www.vendian.org/mncharity/dir3/blackbody/
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//http://www.vendian.org/mncharity/dir3/blackbody/UnstableURLs/bbr_color.html
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vec3 blackbody(float Temp)
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{
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vec3 col = vec3(255.);
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col.x = 56100000. * pow(Temp,(-3. / 2.)) + 148.;
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col.y = 100.04 * log(Temp) - 623.6;
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if (Temp > 6500.) col.y = 35200000. * pow(Temp,(-3. / 2.)) + 184.;
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col.z = 194.18 * log(Temp) - 1448.6;
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col = clamp(col, 0., 255.)/255.;
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if (Temp < 1000.) col *= Temp/1000.;
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return col;
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}
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// -------------blackbody----------------- //
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void mainImage(out vec4 c_out, in vec2 f)
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{
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t = iTime*.125;
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vec3 col = vec3(0., 0., 0.);
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vec2 R = iResolution.xy,
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uv = vec2(f-R/2.) / R.y;
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vec3 dir = camera(uv);
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vec3 pos = vec3(.0, .0, 0.0);
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pos.z = 4.5+1.5*sin(t*10.); // add camera movement
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h*=0.;
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vec2 inter = (march(pos, dir));
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col.xyz = ret_col*(1.-inter.x*.0125);
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col += h * .4;
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c_out = vec4(col,1.0);
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}
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void main() {
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iTime = time;
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iResolution = resolution;
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mainImage(gl_FragColor, gl_FragCoord.xy);
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}
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float scene(vec3 p)
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{
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float var;
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float mind = 1e5;
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// overall object placement
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p.z += 25.;
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rotate(p.xz, 1.57-.5*iTime );
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rotate(p.yz, 1.57-.5*iTime );
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var = atan(p.x,p.y);
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vec2 q = vec2( ( length(p.xy) )-9.,p.z);
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float ttwists=0.75;
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rotate(q, var*ttwists+iTime*0.4);
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vec2 oq = q ;
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q = abs(q)-vec2(3.,3.)-sin(q)*7.; // add some twists
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float twist= 3.3; // twists the "blue" strands
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float s= iTime*1.; // add "movement speed" to the "blue" strands
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if (oq.x < q.x && oq.y > q.y){
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rotate(q, ( (var*twist)+s)*3.14+s);
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}else{
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rotate(q, ( 0.28-(var*twist)+s)*3.14+s);
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}
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float oldvar = var;
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ret_col = 1.-vec3(.350, .2, .3);
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q=q*0.2;
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mind = length(q)+.5+1.05*(length(fract(q*.5*(3.+3.*sin(oldvar*1. - iTime*1.)) )-.5)-1.215);
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// only the coloring:
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h -= vec3(-3.20,.20,1.0)*vec3(1.)*.0025/(.051+(mind-sin(oldvar*1. - iTime*2. + 3.14)*.125 )*(mind-sin(oldvar*1. - iTime*2. + 3.14)*.125 ) );
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h -= vec3(1.20,-.50,-.50)*vec3(1.)*.025/(.501+(mind-sin(oldvar*1. - iTime*2.)*.5 )*(mind-sin(oldvar*1. - iTime*2.)*.5 ) );
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h += vec3(.25, .4, .5)*.0025/(.021+mind*mind);
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// add some music feedback
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return (mind);
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}
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vec2 march(vec3 pos, vec3 dir)
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{
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vec2 dist = vec2(0.0, 0.0);
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vec3 p = vec3(0.0, 0.0, 0.0);
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vec2 s = vec2(0.0, 0.0);
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for (float i = -1.; i < I_MAX; ++i)
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{
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p = pos + dir * dist.y;
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dist.x = scene(p);
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dist.y += dist.x*.2; // makes artefacts disappear
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// log trick by aiekick
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if (log(dist.y*dist.y/dist.x/1e5) > .0 || dist.x < E || dist.y > FAR)
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{
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break;
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}
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s.x++;
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}
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s.y = dist.y;
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return (s);
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}
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// Utilities
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void rotate(inout vec2 v, float angle)
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{
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v = vec2(cos(angle)*v.x+sin(angle)*v.y,-sin(angle)*v.x+cos(angle)*v.y);
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}
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vec3 camera(vec2 uv)
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{
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float fov = 1.;
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vec3 forw = vec3(0.0, 0.0, -1.0);
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vec3 right = vec3(1.0, 0.0, 0.0);
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vec3 up = vec3(0.0, 1.0, 0.0);
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return (normalize((uv.x) * right + (uv.y) * up + fov * forw));
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}
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