IP-MacScan （含源码，代码编译）

import java.io.*; class RandomLCG { long mSeed; // java has no unsigned int public RandomLCG(long seed) { mSeed = seed; } public double nextDouble() { mSeed = (214013L * mSeed + 2531011L) % 0x100000000L; return mSeed * (1.0 / 4294967296.0); } } class Vec { public final double x, y, z; // position, also color (r,g,b) public static final Vec Zero = new Vec(0, 0, 0); public Vec(double x, double y, double z) { this.x = x; this.y = y; this.z = z; } public Vec add(Vec b) { return new Vec(x + b.x, y + b.y, z + b.z); } public Vec sub(Vec b) { return new Vec(x - b.x, y - b.y, z - b.z); } public Vec mul(double b) { return new Vec(x * b, y * b, z * b); } public Vec mult(Vec b) { return new Vec(x * b.x, y * b.y, z * b.z); } public Vec norm() { return this.mul(1 / Math.sqrt(x * x + y * y + z * z)); } public double dot(Vec b) { return x * b.x + y * b.y + z * b.z; } public Vec cross(Vec b) { return new Vec(y * b.z - z * b.y, z * b.x - x * b.z, x * b.y - y * b.x); } } // material types, used in radiance() enum Refl_t { DIFF, SPEC, REFR }; class Ray { public Vec o, d; public Ray(Vec o, Vec d) { this.o = o; this.d = d; } } class Sphere { public double rad; // radius public Vec p, e, c; // position, emission, color public Refl_t refl; // reflection type (DIFFuse, SPECular, REFRactive) public double maxC; public Vec cc; private double sqRad; public Sphere(double rad, Vec p, Vec e, Vec c, Refl_t refl) { this.rad = rad; this.p = p; this.e = e; this.c = c; this.refl = refl; sqRad = rad * rad; maxC = Math.max(Math.max(c.x, c.y), c.z); cc = c.mul(1.0 / maxC); } // returns distance, 0 if nohit public double intersect(Ray r) { Vec op = p.sub(r.o); // Solve t^2*d.d + 2*t*(o-p).d + (o-p).(o-p)-R^2 = 0 double eps = 1e-4; double b = op.dot(r.d); double det = b * b - op.dot(op) + sqRad; if (det < 0) return 0; else { double dets = Math.sqrt(det); if (b - dets > eps) return b - dets; else if (b + dets > eps) return b + dets; else return 0; } } } // Java has no pass by ref class IntersectResult { public double t = 1e20; public Sphere s; } class smallpt { //static java.util.Random random = new java.util.Random(); static RandomLCG random = new RandomLCG(0L); static double rand() { return random.nextDouble(); } //Scene: radius, position, emission, color, material static Sphere[] spheres = { new Sphere(1e5, new Vec( 1e5+1,40.8,81.6), Vec.Zero,new Vec(.75,.25,.25),Refl_t.DIFF),//Left new Sphere(1e5, new Vec(-1e5+99,40.8,81.6),Vec.Zero,new Vec(.25,.25,.75),Refl_t.DIFF),//Rght new Sphere(1e5, new Vec(50,40.8, 1e5), Vec.Zero,new Vec(.75,.75,.75),Refl_t.DIFF),//Back new Sphere(1e5, new Vec(50,40.8,-1e5+170), Vec.Zero,Vec.Zero, Refl_t.DIFF),//Frnt new Sphere(1e5, new Vec(50, 1e5, 81.6), Vec.Zero,new Vec(.75,.75,.75),Refl_t.DIFF),//Botm new Sphere(1e5, new Vec(50,-1e5+81.6,81.6),Vec.Zero,new Vec(.75,.75,.75),Refl_t.DIFF),//Top new Sphere(16.5,new Vec(27,16.5,47), Vec.Zero,new Vec(1,1,1).mul(.999), Refl_t.SPEC),//Mirr new Sphere(16.5,new Vec(73,16.5,78), Vec.Zero,new Vec(1,1,1).mul(.999), Refl_t.REFR),//Glas new Sphere(600, new Vec(50,681.6-.27,81.6),new Vec(12,12,12), Vec.Zero, Refl_t.DIFF) //Lite }; static double clamp(double x) { if (x < 0) return 0; else if (x > 1) return 1; else return x; } static int toInt(double x) { return (int)(Math.pow(clamp(x), 1 / 2.2) * 255 + .5); } static IntersectResult intersect(Ray r) { IntersectResult result = new IntersectResult(); for (Sphere s : spheres) { double d = s.intersect(r); if (d != 0 && d < result.t) { result.t = d; result.s = s; } } return result; } static Vec radiance(Ray r, int depth) { IntersectResult ires = intersect(r); if (ires.s == null) { return Vec.Zero; // if miss, return black } else { Sphere obj = ires.s; // the hit object double t = ires.t; int newDepth = depth + 1; boolean isMaxDepth = newDepth > 100; // Russian roulette for path termination boolean isUseRR = newDepth > 5; boolean isRR = isUseRR && rand() < obj.maxC; if (isMaxDepth || (isUseRR && !isRR)) return obj.e; else { Vec f = (isUseRR && isRR) ? obj.cc : obj.c; Vec x = r.o.add(r.d.mul(t)); Vec n = x.sub(obj.p).norm(); Vec nl = n.dot(r.d) < 0 ? n : n.mul(-1); if (obj.refl == Refl_t.DIFF) // Ideal DIFFUSE reflection { double r1 = 2 * Math.PI * rand(); double r2 = rand(); double r2s = Math.sqrt(r2); Vec w = nl; Vec wo = Math.abs(w.x) > .1 ? new Vec(0, 1, 0) : new Vec(1, 0, 0); Vec u = wo.cross(w).norm(); Vec v = w.cross(u); Vec d = (u.mul(Math.cos(r1) * r2s).add(v.mul(Math.sin(r1) * r2s)).add(w.mul(Math.sqrt(1 - r2)))).norm(); return obj.e.add(f.mult(radiance(new Ray(x, d), newDepth))); } else if (obj.refl == Refl_t.SPEC) // Ideal SPECULAR reflection { return obj.e.add(f.mult(radiance(new Ray(x, r.d.sub(n.mul(2 * n.dot(r.d)))), newDepth))); } else // Ideal dielectric REFRACTION { Ray reflRay = new Ray(x, r.d.sub(n.mul(2 * n.dot(r.d)))); boolean into = n.dot(nl) > 0; // Ray from outside going in? double nc = 1; double nt = 1.5; double nnt = into ? nc / nt : nt / nc; double ddn = r.d.dot(nl); double cos2t = 1 - nnt * nnt * (1 - ddn * ddn); if (cos2t < 0) // Total internal reflection { return obj.e.add(f.mult(radiance(reflRay, newDepth))); } else { Vec tdir = (r.d.mul(nnt).sub(n.mul((into ? 1 : -1) * (ddn * nnt + Math.sqrt(cos2t))))).norm(); double a = nt - nc; double b = nt + nc; double R0 = a * a / (b * b); double c = 1 - (into ? -ddn : tdir.dot(n)); double Re = R0 + (1 - R0) * c * c * c * c * c; double Tr = 1 - Re; double P = .25 + .5 * Re; double RP = Re / P; double TP = Tr / (1 - P); Vec result; if (newDepth > 2) { // Russian roulette and splitting for selecting reflection and/or refraction if (rand() < P) result = radiance(reflRay, newDepth).mul(RP); else result = radiance(new Ray(x, tdir), newDepth).mul(TP); } else result = radiance(reflRay, newDepth).mul(Re).add(radiance(new Ray(x, tdir), newDepth).mul(Tr)); return obj.e.add(f.mult(result)); } } } } } public static void main(String[] args) { long start = System.currentTimeMillis(); int w = 256; int h = 256; int samps = args.length == 2 ? Integer.parseInt(args[1]) / 4 : 25; // # samples // cam pos, dir Ray cam = new Ray(new Vec(50, 52, 295.6), new Vec(0, -0.042612, -1).norm()); Vec cx = new Vec(w * .5135 / h, 0, 0); Vec cy = (cx.cross(cam.d)).norm().mul(.5135); // final color buffer Vec[] c = new Vec[w * h]; // Loop over image rows for (int y = 0; y < h; y++) { System.out.printf("\rRendering (%d spp) %5.2f%%", samps * 4, 100.0 * y / (h - 1)); // Loop cols for (int x = 0; x < w; x++) { // 2x2 subpixel rows for (int sy = 0; sy < 2; sy++) { int i = (h - y - 1) * w + x; c[i] = Vec.Zero; // 2x2 subpixel cols for (int sx = 0; sx < 2; sx++) { Vec r = Vec.Zero; for (int s = 0; s < samps; s++) { double r1 = 2 * rand(); double r2 = 2 * rand(); double dx = r1 < 1 ? Math.sqrt(r1) - 1 : 1 - Math.sqrt