mod3Checkpoint_theforce.glsl

const int steps = 16;
const float smallNumber = 0.001;
const float maxDist = 2.;

// Repeat in three dimensions
vec3 pMod3(inout vec3 p, vec3 size) {
	vec3 c = floor((p + size*0.5)/size);
	p = mod(p + size*0.5, size) - size*0.5;
	return c;
}

float scene(vec3 position){

    
    
    float ground = position.y +
                    sin(position.x * 10.)/10.+
                    cos(position.z * 10.)/10.+
                    0.5;
    
    vec3 modSpace = vec3(4,1,2);
    
    pMod3(position, modSpace);
    float sphere = length(
        vec3(position.x + sin(time),
        position.y,
        position.z + 1.0
        ))- 0.5;
    return  min( ground, sphere);
    
}

vec4 march(vec3 rayOrigin, vec3 direction){
    vec3 ray = rayOrigin;
    float dist = 0.;
    float totalDist = 0.;
    for(float i = 0. ; i < 1.0 ; i += 0.00001){
        dist = scene(ray);
        ray = ray + dist * direction;
        totalDist+= dist;
        if(dist < smallNumber){
            return vec4(1.0 - (totalDist/maxDist));
        }
        if(totalDist > maxDist){
            break;
        }
    }
   return vec4(0.);
    
}

void main () {
    
    vec2 pos = uv();
    
    vec3 camOrigin = vec3(0,0,-1);
    
    vec3 rayOrigin = vec3(camOrigin.xy + pos,camOrigin.z + 1.0);
    
    vec3 direction = normalize(camOrigin + rayOrigin);
 
    vec4 color = march(rayOrigin, direction);
    
	gl_FragColor = clamp(color,0.,0.75);
}