平行投影カメラと繰り返し
See the Pen repetition with orthographic camera by aadebdeb (@aadebdeb) on CodePen.
#define PI 3.14159265359 #define TWO_PI PI * 2.0 #define HALF_PI PI / 2.0 precision mediump float; uniform float u_time; uniform vec2 u_mouse; uniform vec2 u_resolution; vec3 repeat(vec3 p, vec3 interval) { return mod(p, interval) - interval / 2.0; } vec3 rotateX(vec3 p, float theta) { float c = cos(-theta); float s = sin(-theta); mat3 m = mat3(vec3(1, 0.0, 0.0), vec3(0.0, c, -s), vec3(0.0, s, c)); return m * p; } vec3 rotateY(vec3 p, float theta) { float c = cos(-theta); float s = sin(-theta); mat3 m = mat3(vec3(c, 0.0, s), vec3(0.0, 1.0, 0.0), vec3(-s, 0.0, c)); return m * p; } vec3 rotateZ(vec3 p, float theta) { float c = cos(-theta); float s = sin(-theta); mat3 m = mat3(vec3(c, -s, 0.0), vec3(s, c, 0.0), vec3(0.0, 0.0, 1.0)); return m * p; } vec3 translate(vec3 p, vec3 t) { mat4 m = mat4(vec4(1.0, 0.0, 0.0, 0.0), vec4(0.0, 1.0, 0.0, 0.0), vec4(0.0, 0.0, 1.0, 0.0), vec4(-t.x, -t.y, -t.z, 1.0)); return (m * vec4(p, 1.0)).xyz; } float calcBoxDistance(vec3 p, vec3 size) { return length(max(abs(p) - size, 0.0)); } float calcSphereDistance(vec3 p, float size) { return length(p) - size; } float calcDistance(vec3 p) { vec3 q = repeat(p, vec3(4.0)); return calcSphereDistance(q, 1.0); } vec3 calcNormal(vec3 p) { float delta = 0.00001; return normalize(vec3( calcDistance(p + vec3(delta, 0.0, 0.0)) - calcDistance(p - vec3(delta, 0.0, 0.0)), calcDistance(p + vec3(0.0, delta, 0.0)) - calcDistance(p - vec3(0.0, delta, 0.0)), calcDistance(p + vec3(0.0, 0.0, delta)) - calcDistance(p - vec3(0.0, 0.0, delta)) )); } void main(void) { vec2 st = (gl_FragCoord.xy * 2.0 - u_resolution) / min(u_resolution.x, u_resolution.y); vec2 mouse = (u_mouse * 2.0 - u_resolution) / min(u_resolution.x, u_resolution.y); vec3 cameraPosition = vec3(0.0, 0.0, 0.0); vec3 viewCenter = cameraPosition + vec3(cos(mouse.x * PI), sin(mouse.y * HALF_PI), sin(mouse.x * PI)); vec3 viewDirection = normalize(viewCenter - cameraPosition); vec3 cameraTop = vec3(0.0, 1.0, 0.0); vec3 cameraSide = cross(viewDirection, cameraTop); vec3 rayDirection = viewDirection; float viewWidth = 50.0; float viewHeight = 50.0; vec3 rayPosition = cameraPosition + vec3(cameraTop * st.y * viewHeight / 2.0 + cameraSide * st.x * viewWidth / 2.0); float radian = u_time * 0.0003; vec3 lightPosition = vec3(5.0, 5.0, 5.0); vec3 color = vec3(0.0); float d; for (int i = 0; i < 256; i++) { d = calcDistance(rayPosition); rayPosition += rayDirection * d; } if (d < 0.0001) { vec3 normal = calcNormal(rayPosition); float weight = dot(normal, normalize(lightPosition)); color = vec3(1.0) * max(weight, 0.0) + vec3(0.1); } gl_FragColor = vec4(color, 1.0); }