200 lines
4.5 KiB
GLSL
200 lines
4.5 KiB
GLSL
//noise3.jpg
|
|
//Plasma Globe by nimitz (twitter: @stormoid)
|
|
|
|
//looks best with around 25 rays
|
|
#define NUM_RAYS 13.
|
|
|
|
#define VOLUMETRIC_STEPS 19
|
|
|
|
#define MAX_ITER 35
|
|
#define FAR 6.
|
|
|
|
#define time iGlobalTime*1.1
|
|
|
|
|
|
mat2 mm2(in float a){float c = cos(a), s = sin(a);return mat2(c,-s,s,c);}
|
|
float noise( in float x ){return textureLod(iChannel0, vec2(x*.01,1.),0.0).x;}
|
|
|
|
float hash( float n ){return fract(sin(n)*43758.5453);}
|
|
|
|
//iq's ubiquitous 3d noise
|
|
float noise(in vec3 p)
|
|
{
|
|
vec3 ip = floor(p);
|
|
vec3 f = fract(p);
|
|
f = f*f*(3.0-2.0*f);
|
|
|
|
vec2 uv = (ip.xy+vec2(37.0,17.0)*ip.z) + f.xy;
|
|
vec2 rg = textureLod( iChannel0, (uv+ 0.5)/256.0, 0.0 ).yx;
|
|
return mix(rg.x, rg.y, f.z);
|
|
}
|
|
|
|
mat3 m3 = mat3( 0.00, 0.80, 0.60,
|
|
-0.80, 0.36, -0.48,
|
|
-0.60, -0.48, 0.64 );
|
|
|
|
|
|
//See: https://www.shadertoy.com/view/XdfXRj
|
|
float flow(in vec3 p, in float t)
|
|
{
|
|
float z=2.;
|
|
float rz = 0.;
|
|
vec3 bp = p;
|
|
for (float i= 1.;i < 5.;i++ )
|
|
{
|
|
p += time*.1;
|
|
rz+= (sin(noise(p+t*0.8)*6.)*0.5+0.5) /z;
|
|
p = mix(bp,p,0.6);
|
|
z *= 2.;
|
|
p *= 2.01;
|
|
p*= m3;
|
|
}
|
|
return rz;
|
|
}
|
|
|
|
//could be improved
|
|
float sins(in float x)
|
|
{
|
|
float rz = 0.;
|
|
float z = 2.;
|
|
for (float i= 0.;i < 3.;i++ )
|
|
{
|
|
rz += abs(fract(x*1.4)-0.5)/z;
|
|
x *= 1.3;
|
|
z *= 1.15;
|
|
x -= time*.65*z;
|
|
}
|
|
return rz;
|
|
}
|
|
|
|
float segm( vec3 p, vec3 a, vec3 b)
|
|
{
|
|
vec3 pa = p - a;
|
|
vec3 ba = b - a;
|
|
float h = clamp( dot(pa,ba)/dot(ba,ba), 0.0, 1. );
|
|
return length( pa - ba*h )*.5;
|
|
}
|
|
|
|
vec3 path(in float i, in float d)
|
|
{
|
|
vec3 en = vec3(0.,0.,1.);
|
|
float sns2 = sins(d+i*0.5)*0.22;
|
|
float sns = sins(d+i*.6)*0.21;
|
|
en.xz *= mm2((hash(i*10.569)-.5)*6.2+sns2);
|
|
en.xy *= mm2((hash(i*4.732)-.5)*6.2+sns);
|
|
return en;
|
|
}
|
|
|
|
vec2 map(vec3 p, float i)
|
|
{
|
|
float lp = length(p);
|
|
vec3 bg = vec3(0.);
|
|
vec3 en = path(i,lp);
|
|
|
|
float ins = smoothstep(0.11,.46,lp);
|
|
float outs = .15+smoothstep(.0,.15,abs(lp-1.));
|
|
p *= ins*outs;
|
|
float id = ins*outs;
|
|
|
|
float rz = segm(p, bg, en)-0.011;
|
|
return vec2(rz,id);
|
|
}
|
|
|
|
float march(in vec3 ro, in vec3 rd, in float startf, in float maxd, in float j)
|
|
{
|
|
float precis = 0.001;
|
|
float h=0.5;
|
|
float d = startf;
|
|
for( int i=0; i<MAX_ITER; i++ )
|
|
{
|
|
if( abs(h)<precis||d>maxd ) break;
|
|
d += h*1.2;
|
|
float res = map(ro+rd*d, j).x;
|
|
h = res;
|
|
}
|
|
return d;
|
|
}
|
|
|
|
//volumetric marching
|
|
vec3 vmarch(in vec3 ro, in vec3 rd, in float j, in vec3 orig)
|
|
{
|
|
vec3 p = ro;
|
|
vec2 r = vec2(0.);
|
|
vec3 sum = vec3(0);
|
|
float w = 0.;
|
|
for( int i=0; i<VOLUMETRIC_STEPS; i++ )
|
|
{
|
|
r = map(p,j);
|
|
p += rd*.03;
|
|
float lp = length(p);
|
|
|
|
vec3 col = sin(vec3(1.05,2.5,1.52)*3.94+r.y)*.85+0.4;
|
|
col.rgb *= smoothstep(.0,.015,-r.x);
|
|
col *= smoothstep(0.04,.2,abs(lp-1.1));
|
|
col *= smoothstep(0.1,.34,lp);
|
|
sum += abs(col)*5. * (1.2-noise(lp*2.+j*13.+time*5.)*1.1) / (log(distance(p,orig)-2.)+.75);
|
|
}
|
|
return sum;
|
|
}
|
|
|
|
//returns both collision dists of unit sphere
|
|
vec2 iSphere2(in vec3 ro, in vec3 rd)
|
|
{
|
|
vec3 oc = ro;
|
|
float b = dot(oc, rd);
|
|
float c = dot(oc,oc) - 1.;
|
|
float h = b*b - c;
|
|
if(h <0.0) return vec2(-1.);
|
|
else return vec2((-b - sqrt(h)), (-b + sqrt(h)));
|
|
}
|
|
|
|
void mainImage( out vec4 fragColor, in vec2 fragCoord )
|
|
{
|
|
vec2 p = fragCoord.xy/iResolution.xy-0.5;
|
|
p.x*=iResolution.x/iResolution.y;
|
|
vec2 um = iMouse.xy / iResolution.xy-.5;
|
|
|
|
//camera
|
|
vec3 ro = vec3(0.,0.,5.);
|
|
vec3 rd = normalize(vec3(p*.7,-1.5));
|
|
mat2 mx = mm2(time*.4+um.x*6.);
|
|
mat2 my = mm2(time*0.3+um.y*6.);
|
|
ro.xz *= mx;rd.xz *= mx;
|
|
ro.xy *= my;rd.xy *= my;
|
|
|
|
vec3 bro = ro;
|
|
vec3 brd = rd;
|
|
|
|
vec3 col = vec3(0.0125,0.,0.025);
|
|
#if 1
|
|
for (float j = 1.;j<NUM_RAYS+1.;j++)
|
|
{
|
|
ro = bro;
|
|
rd = brd;
|
|
mat2 mm = mm2((time*0.1+((j+1.)*5.1))*j*0.25);
|
|
ro.xy *= mm;rd.xy *= mm;
|
|
ro.xz *= mm;rd.xz *= mm;
|
|
float rz = march(ro,rd,2.5,FAR,j);
|
|
if ( rz >= FAR)continue;
|
|
vec3 pos = ro+rz*rd;
|
|
col = max(col,vmarch(pos,rd,j, bro));
|
|
}
|
|
#endif
|
|
|
|
ro = bro;
|
|
rd = brd;
|
|
vec2 sph = iSphere2(ro,rd);
|
|
|
|
if (sph.x > 0.)
|
|
{
|
|
vec3 pos = ro+rd*sph.x;
|
|
vec3 pos2 = ro+rd*sph.y;
|
|
vec3 rf = reflect( rd, pos );
|
|
vec3 rf2 = reflect( rd, pos2 );
|
|
float nz = (-log(abs(flow(rf*1.2,time)-.01)));
|
|
float nz2 = (-log(abs(flow(rf2*1.2,-time)-.01)));
|
|
col += (0.1*nz*nz* vec3(0.12,0.12,.5) + 0.05*nz2*nz2*vec3(0.55,0.2,.55))*0.8;
|
|
}
|
|
|
|
fragColor = vec4(col*1.3, 1.0);
|
|
} |