64 lines
1.7 KiB
GLSL
64 lines
1.7 KiB
GLSL
// Based on https://www.shadertoy.com/view/XlfGRj by Pablo Roman Andrioli
|
|
// Licensed under MIT
|
|
|
|
shader_type canvas_item;
|
|
|
|
render_mode unshaded;
|
|
|
|
const int volsteps = 20;
|
|
const int iterations = 17;
|
|
const float formuparam = 0.53;
|
|
const float stepsize = 0.1;
|
|
const float brightness = 0.0015;
|
|
const float darkmatter = 0.300;
|
|
const float distfading = 0.730;
|
|
const float saturation = 0.850;
|
|
const float rotx = 0.;
|
|
const float roty = 0.001;
|
|
const float tile = 0.85;
|
|
|
|
uniform float speed = 0.001;
|
|
uniform float zoom = 0.80;
|
|
|
|
void fragment() {
|
|
vec2 uv = FRAGCOORD.xy * SCREEN_PIXEL_SIZE - 0.5;
|
|
uv.y *= SCREEN_PIXEL_SIZE.x/SCREEN_PIXEL_SIZE.y;
|
|
|
|
vec3 dir = vec3(uv*(zoom+sin(TIME*0.01)*0.4), 1.);
|
|
float time = TIME*speed+.25;
|
|
|
|
float a1=.5+TIME*rotx;
|
|
float a2=.8+TIME*roty;
|
|
mat2 rot1=mat2(vec2(cos(a1),sin(a1)),vec2(-sin(a1),cos(a1)));
|
|
mat2 rot2=mat2(vec2(cos(a2),sin(a2)),vec2(-sin(a2),cos(a2)));
|
|
dir.xz*=rot1;
|
|
dir.xy*=rot2;
|
|
vec3 from=vec3(1.,.5,0.5);
|
|
from+=vec3(time*2.,time,-2.);
|
|
from.xz*=rot1;
|
|
from.xy*=rot2;
|
|
|
|
//volumetric rendering
|
|
float s=0.1,fade=1.;
|
|
vec3 v=vec3(0.);
|
|
for (int r=0; r<volsteps; r++) {
|
|
vec3 p=from+s*dir*.5;
|
|
p = abs(vec3(tile)-mod(p,vec3(tile*2.))); // tiling fold
|
|
float pa,a=pa=0.;
|
|
for (int i=0; i<iterations; i++) {
|
|
p=abs(p)/dot(p,p)-formuparam; // the magic formula
|
|
a+=abs(length(p)-pa); // absolute sum of average change
|
|
pa=length(p);
|
|
}
|
|
float dm=max(0.,darkmatter-a*a*.001); //dark matter
|
|
a*=a*a; // add contrast
|
|
if (r>6) fade*=1.-dm; // dark matter, don't render near
|
|
//v+=vec3(dm,dm*.5,0.);
|
|
v+=fade;
|
|
v+=vec3(s,s*s,s*s*s*s)*a*brightness*fade; // coloring based on distance
|
|
fade*=distfading; // distance fading
|
|
s+=stepsize;
|
|
}
|
|
v=mix(vec3(length(v)),v,saturation); //color adjust
|
|
COLOR = vec4(v*.01,1.);
|
|
} |