precision highp float; uniform vec2 resolution; const float PI = acos(-1.); mat3 rotX(float q){return mat3(1.,0.,0.,0.,cos(q),-sin(q),0.,sin(q),cos(q));} mat3 rotY(float q){return mat3(cos(q),0.,sin(q),0.,1.,0.,-sin(q),0.,cos(q));} mat3 rotZ(float q){return mat3(cos(q),-sin(q),0.,sin(q),cos(q),0.,0.,0.,1.);} float random(vec2 p){return fract(sin(dot(p,vec2(12.9898,78.233)))*43758.5453);} float WIRE_R = .08; // SDF from https://www.iquilezles.org/www/articles/distfunctions/distfunctions.htm float sdCappedCylinder( vec3 p, float h, float r ) { vec2 d = abs(vec2(length(p.xz),p.y)) - vec2(h,r); return min(max(d.x,d.y),0.0) + length(max(d,0.0)); } float dCore1(vec3 p){ p = rotZ(PI/4.)*p; p.x = mod(p.x+sqrt(2.)/2., sqrt(2.))-sqrt(2.)/2.; p.y = mod(p.y+sqrt(2.)/2., sqrt(2.))-sqrt(2.)/2.; float d = max(sdCappedCylinder(p, .4,.12),-sdCappedCylinder(p, .28,.2)); return d; } float dCore2(vec3 p){ p.x += 1.; p = rotZ(-PI/4.)*p; p.x = mod(p.x+sqrt(2.)/2., sqrt(2.))-sqrt(2.)/2.; p.y = mod(p.y+sqrt(2.)/2., sqrt(2.))-sqrt(2.)/2.; float d = max(sdCappedCylinder(p, .4,.12),-sdCappedCylinder(p, .28,.2)); return d; } float dCore(vec3 p){ float d = min(dCore1(p),dCore2(p)); return d; } float dFloor(vec3 p){ float d = (-p.z + .5); return d; } float dFrontWires(vec3 p){ p.x = mod(p.x+0.5, 1.) - 0.5; float d = length(vec2(p.x, p.z+WIRE_R*1.5)) - WIRE_R; return d; } float dBackWires(vec3 p){ p.y = mod(p.y+0.5, 1.) - 0.5; float d = length(vec2(p.y, p.z-WIRE_R*1.5)) - WIRE_R; return d; } float distFunc(vec3 p){ float d = 1e3; d = min(d, dFrontWires(p)); d = min(d, dBackWires(p)); d = min(d, dFloor(p)); d = min(d, dCore(p)); return d; } vec3 normFunc(vec3 p){ float d = 0.001; float dx = distFunc(p+vec3(d, 0., 0.)) - distFunc(p); float dy = distFunc(p+vec3(0., d, 0.)) - distFunc(p); float dz = distFunc(p+vec3(0., 0., d)) - distFunc(p); return normalize(vec3(dx, dy, dz)); } vec3 colorFunc(vec3 p){ float d_fwire = dFrontWires(p); float d_bwire = dBackWires(p); float d_floor = dFloor(p); float d_core = dCore(p); if (d_fwire < d_bwire && d_fwire < d_floor && d_fwire < d_core){ return vec3(0.8,0,0); } else if (d_bwire < d_floor && d_bwire < d_core){ return vec3(0,0.5,.2); } else if (d_core < d_floor){ return vec3(.3)+random(p.xy+p.zy)*.1; } return vec3(1); } void main(){ //短辺が-1~1となる二次元座標 vec2 p = (gl_FragCoord.xy * 2.0 - resolution.xy) / min(resolution.x, resolution.y); //カメラの位置、向き vec3 cDir = normalize(vec3(0., 2., 4.)); vec3 cPos = -cDir*12.; vec3 cUp = normalize(vec3(0., 1., 0.)); vec3 cSide = cross(cDir,cUp); // レイ vec3 rDir = normalize(cSide * p.x + cUp * p.y + cDir * 2.); vec3 rPos = cPos; //　点光源 vec3 lPos = normalize(vec3(1,1,-3))*8.; // vec3 lPos = cPos; // マーチングループ float d, dLim = 1e-3; for (int i=0; i<200; i++){ d = distFunc(rPos); if (d < dLim) break; rPos += d * rDir; } // 影のマーチングループ vec3 shDir = normalize(lPos-rPos); vec3 shPos = rPos + shDir*dLim*100.; bool shaded = false; float shD; for (int i=0; i<200; i++){ shD = distFunc(shPos); if (length(shPos - lPos) < dLim) { // 光源にたどり着いたら影なし break; } else if (shD < dLim) { // 光源にたどり着かずに何かに衝突したら影なし shaded = true; break; } shPos += shD * shDir; } // 色の設定 vec3 color = colorFunc(rPos); float r = length(rPos - lPos); float shade = clamp(dot(-normFunc(rPos), normalize(rPos-lPos)), 0., 1.); shade *= 80./r/r; if (shaded) { shade *= 0.5; } gl_FragColor = vec4(color*shade, 1.); }

磁気コアメモリ