public override int GetMoreSamples(Sample[] samples, Random rng)
{
if (_yPos == YEnd)
{
return(0);
}
int nSamples = _xPixelSamples * _yPixelSamples;
// Generate stratified camera samples for _(xPos, yPos)_
// Generate initial stratified samples into _sampleBuf_ memory
IList <float> imageSamples = new ArraySegment <float>(_sampleBuffer, 0, 2 * nSamples);
IList <float> lensSamples = new ArraySegment <float>(_sampleBuffer, 2 * nSamples, 2 * nSamples);
IList <float> timeSamples = new ArraySegment <float>(_sampleBuffer, 4 * nSamples, nSamples);
SamplingUtilities.StratifiedSample2D(imageSamples, _xPixelSamples, _yPixelSamples, rng, _jitter);
SamplingUtilities.StratifiedSample2D(lensSamples, _xPixelSamples, _yPixelSamples, rng, _jitter);
SamplingUtilities.StratifiedSample1D(timeSamples, _xPixelSamples * _yPixelSamples, rng, _jitter);
// Shift stratified image samples to pixel coordinates
for (int o = 0; o < 2 * _xPixelSamples * _yPixelSamples; o += 2)
{
imageSamples[o] += _xPos;
imageSamples[o + 1] += _yPos;
}
// Decorrelate sample dimensions
SamplingUtilities.Shuffle(lensSamples, _xPixelSamples * _yPixelSamples, 2, rng);
SamplingUtilities.Shuffle(timeSamples, _xPixelSamples * _yPixelSamples, 1, rng);
// Initialize stratified _samples_ with sample values
for (int i = 0; i < nSamples; ++i)
{
samples[i].ImageX = imageSamples[2 * i];
samples[i].ImageY = imageSamples[2 * i + 1];
samples[i].LensU = lensSamples[2 * i];
samples[i].LensV = lensSamples[2 * i + 1];
samples[i].Time = MathUtility.Lerp(timeSamples[i], ShutterOpen, ShutterClose);
// Generate stratified samples for integrators
for (var j = 0; j < samples[i].Num1D.Count; ++j)
{
MonteCarloUtilities.LatinHypercube(samples[i].OneD[j], samples[i].Num1D[j], 1, rng);
}
for (var j = 0; j < samples[i].Num2D.Count; ++j)
{
MonteCarloUtilities.LatinHypercube(samples[i].TwoD[j], samples[i].Num2D[j], 2, rng);
}
}
// Advance to next pixel for stratified sampling
if (++_xPos == XEnd)
{
_xPos = XStart;
++_yPos;
}
return(nSamples);
}
public Spectrum Rho(Vector wo, Random rng, BxdfType flags = BxdfType.All, int sqrtSamples = 6)
{
int nSamples = sqrtSamples * sqrtSamples;
var s1 = new float[2 * nSamples];
SamplingUtilities.StratifiedSample2D(s1, sqrtSamples, sqrtSamples, rng);
Spectrum ret = Spectrum.CreateBlack();
foreach (var bxdf in _bxdfs)
{
if (bxdf.MatchesFlags(flags))
{
ret += bxdf.Rho(wo, nSamples, s1);
}
}
return(ret);
}