public void Render()
{
Scene scene = Scene;
Camera camera = Camera;
Sampler sampler = Sampler;
Buffer buf = PBuffer;
(int w, int h) = (buf.W, buf.H);
int spp = SamplesPerPixel;
int sppRoot = (int)(Math.Sqrt(SamplesPerPixel));
scene.Compile();
scene.rays = 0;
Random rand = new Random();
double fu, fv;
for (int y = 0; y < h; y++)
{
for (int x = 0; x < w; x++)
{
if (StratifiedSampling)
{
for (int u = 0; u < sppRoot; u++)
{
for (int v = 0; v < sppRoot; v++)
{
fu = (u + 0.5) / sppRoot;
fv = (v + 0.5) / sppRoot;
Ray ray = camera.CastRay(x, y, w, h, fu, fv, rand);
Colour sample = sampler.Sample(scene, ray, rand);
buf.AddSample(x, y, sample);
}
}
}
else
{
// Random subsampling
for (int ii = 0; ii < spp; ii++)
{
fu = rand.NextDouble();
fv = rand.NextDouble();
Ray ray = camera.CastRay(x, y, w, h, fu, fv, rand);
Colour sample = sampler.Sample(scene, ray, rand);
buf.AddSample(x, y, sample);
}
}
// Adaptive Sampling
if (AdaptiveSamples > 0)
{
double v = buf.StandardDeviation(x, y).MaxComponent();
v = Util.Clamp(v / AdaptiveThreshold, 0, 1);
v = Math.Pow(v, AdaptiveExponent);
int samples = (int)(v * AdaptiveSamples);
for (int d = 0; d < samples; d++)
{
fu = rand.NextDouble();
fv = rand.NextDouble();
Ray ray = camera.CastRay(x, y, w, h, fu, fv, rand);
Colour sample = sampler.Sample(scene, ray, rand);
buf.AddSample(x, y, sample);
}
}
if (FireflySamples > 0)
{
if (PBuffer.StandardDeviation(x, y).MaxComponent() > FireflyThreshold)
{
for (int e = 0; e < FireflySamples; e++)
{
fu = rand.NextDouble();
fv = rand.NextDouble();
Ray ray = camera.CastRay(x, y, w, h, fu, fv, rand);
Colour sample = sampler.Sample(scene, ray, rand);
PBuffer.AddSample(x, y, sample);
}
}
}
}
}
}
public static Material LightMaterial(Colour color, double emittance)
{
return(new Material(color, null, null, null, null, 1, emittance, 1, 0, 0, -1, false));
}
public void RenderParallel()
{
Scene scene = Scene;
Camera camera = Camera;
Sampler sampler = Sampler;
Buffer buf = PBuffer;
(int w, int h) = (buf.W, buf.H);
int spp = SamplesPerPixel;
int sppRoot = (int)(Math.Sqrt(SamplesPerPixel));
scene.Compile();
scene.rays = 0;
// Stop watch timer
Stopwatch sw = new Stopwatch();
sw.Start();
// Random Number Generator from on Math.Numerics
System.Random rand = new SystemRandomSource(sw.Elapsed.Milliseconds, true);
// Frame resolution
int totalPixels = h * w;
// Create a cancellation token for Parallel.For loop control
CancellationTokenSource cts = new CancellationTokenSource();
// ParallelOptions for Parallel.For
ParallelOptions po = new ParallelOptions();
po.CancellationToken = cts.Token;
// Set number of cores/threads
po.MaxDegreeOfParallelism = Environment.ProcessorCount;
Console.WriteLine("{0} x {1} pixels, {2} spp, {3} core(s)", w, h, spp, po.MaxDegreeOfParallelism);
if (StratifiedSampling)
{
_ = Parallel.For(0, w * h, po, (i, loopState) =>
{
int y = i / w, x = i % w;
for (int u = 0; u < sppRoot; u++)
{
for (int v = 0; v < sppRoot; v++)
{
var fu = (u + 0.5) / sppRoot;
var fv = (v + 0.5) / sppRoot;
Ray ray = camera.CastRay(x, y, w, h, fu, fv, rand);
Colour sample = sampler.Sample(scene, ray, rand);
buf.AddSample(x, y, sample);
}
}
});
Console.WriteLine("time elapsed:" + sw.Elapsed);
}
else
{
//Random subsampling
_ = Parallel.ForEach(Partitioner.Create(0, totalPixels), po, (range) =>
{
for (int i = range.Item1; i < range.Item2; i++)
{
for (int s = 0; s < spp; s++)
{
int y = i / w, x = i % w;
var fu = ThreadSafeRandom.NextDouble(rand);
var fv = ThreadSafeRandom.NextDouble(rand);
var ray = camera.CastRay(x, y, w, h, fu, fv, rand);
var sample = sampler.Sample(scene, ray, rand);
buf.AddSample(x, y, sample);
}
}
});
Console.WriteLine("time elapsed:" + sw.Elapsed);
}
if (AdaptiveSamples > 0)
{
_ = Parallel.For(0, w * h, po, (i, loopState) =>
{
int y = i / w, x = i % w;
double v = buf.StandardDeviation(x, y).MaxComponent();
v = Util.Clamp(v / AdaptiveThreshold, 0, 1);
v = Math.Pow(v, AdaptiveExponent);
int samples = (int)(v * AdaptiveSamples);
for (int s = 0; s < samples; s++)
{
var fu = rand.NextDouble();
var fv = rand.NextDouble();
Ray ray = camera.CastRay(x, y, w, h, fu, fv, rand);
Colour sample = sampler.Sample(scene, ray, rand);
buf.AddSample(x, y, sample);
}
});
}
if (FireflySamples > 0)
{
_ = Parallel.For(0, w * h, po, (i, loopState) =>
{
int y = i / w, x = i % w;
if (PBuffer.StandardDeviation(x, y).MaxComponent() > FireflyThreshold)
{
Parallel.For(0, FireflySamples, po, (e, loop) =>
{
var fu = rand.NextDouble();
var fv = rand.NextDouble();
Ray ray = camera.CastRay(x, y, w, h, fu, fv, rand);
Colour sample = sampler.Sample(scene, ray, rand);
buf.AddSample(x, y, sample);
});
}
});
}
sw.Stop();
}
public static Material TransparentMaterial(Colour color, double index, double gloss, double tint)
{
return(new Material(color, null, null, null, null, 1, 0, index, gloss, tint, -1, true));
}
public static Material MetallicMaterial(Colour color, double gloss, double tint)
{
return(new Material(color, null, null, null, null, 1, 0, 1, gloss, tint, 1, false));
}
public static Material GlossyMaterial(Colour color, double index, double gloss)
{
return(new Material(color, null, null, null, null, 1, 0, index, gloss, 0, -1, false));
}
public static Material SpecularMaterial(Colour color, double index)
{
return(new Material(color, null, null, null, null, 1, 0, index, 0, 0, -1, false));
}
public static Material DiffuseMaterial(Colour color)
{
return(new Material(color, null, null, null, null, 1, 0, 1, 0, 0, -1, false));
}
public void AddSample(int x, int y, Colour sample) => Pixels[y * W + x].AddSample(sample);
public Pixel(int Samples, Colour M, Colour V)
{
this.Samples = Samples;
this.M = M;
this.V = V;
}