Octagrams
https://www.shadertoy.com/view/tlVGDt
Shader code
shader_type canvas_item;
const float REPEAT = 5.0;
mat2 rot(float a) {
float c = cos(a), s = sin(a);
return mat2(vec2(c,s),vec2(-s,c));
}
float sdBox( vec3 p, vec3 b )
{
vec3 q = abs(p) - b;
return length(max(q,0.0)) + min(max(q.x,max(q.y,q.z)),0.0);
}
float box(vec3 pos, float scale) {
pos *= scale;
float base = sdBox(pos, vec3(.4,.4,.1)) /1.5;
pos.xy *= 5.;
pos.y -= 3.5;
pos.xy *= rot(.75);
float result = -base;
return result;
}
float box_set(vec3 pos, float iTime,float gTime) {
vec3 pos_origin = pos;
pos = pos_origin;
pos .y += sin(gTime * 0.4) * 2.5;
pos.xy *= rot(.8);
float box1 = box(pos,2. - abs(sin(gTime * 0.4)) * 1.5);
pos = pos_origin;
pos .y -=sin(gTime * 0.4) * 2.5;
pos.xy *= rot(.8);
float box2 = box(pos,2. - abs(sin(gTime * 0.4)) * 1.5);
pos = pos_origin;
pos .x +=sin(gTime * 0.4) * 2.5;
pos.xy *= rot(.8);
float box3 = box(pos,2. - abs(sin(gTime * 0.4)) * 1.5);
pos = pos_origin;
pos .x -=sin(gTime * 0.4) * 2.5;
pos.xy *= rot(.8);
float box4 = box(pos,2. - abs(sin(gTime * 0.4)) * 1.5);
pos = pos_origin;
pos.xy *= rot(.8);
float box5 = box(pos,.5) * 6.;
pos = pos_origin;
float box6 = box(pos,.5) * 6.;
float result = max(max(max(max(max(box1,box2),box3),box4),box5),box6);
return result;
}
float map(vec3 pos, float iTime, float gTime) {
vec3 pos_origin = pos;
float box_set1 = box_set(pos, iTime, gTime);
return box_set1;
}
void fragment() {
vec2 iResolution = 1.0 / SCREEN_PIXEL_SIZE;
float iTime = TIME;
float gTime = 0.0;
vec2 p = (FRAGCOORD.xy * 2. - iResolution.xy) / min(iResolution.x, iResolution.y);
vec3 ro = vec3(0., -0.2 ,iTime * 4.);
vec3 ray = normalize(vec3(p, 1.5));
ray.xy = ray.xy * rot(sin(iTime * .03) * 5.);
ray.yz = ray.yz * rot(sin(iTime * .05) * .2);
float t = 0.1;
vec3 col = vec3(0.);
float ac = 0.0;
for (int i = 0; i < 99; i++){
vec3 pos = ro + ray * t;
pos = mod(pos-2., 4.) -2.;
gTime = iTime -float(i) * 0.01;
float d = map(pos, iTime, gTime);
d = max(abs(d), 0.01);
ac += exp(-d*23.);
t += d* 0.55;
}
col = vec3(ac * 0.02);
col +=vec3(0.,0.2 * abs(sin(iTime)),0.5 + sin(iTime) * 0.2);
COLOR = vec4(col ,1.0 - t * (0.02 + 0.02 * sin (iTime)));
}