public static Spectrum UniformSampleOneLight(this Interaction it,
IScene scene,
IObjectArena arena,
ISampler sampler,
bool handleMedia = false,
Distribution1D lightDistribution = null)
{
var nLights = scene.Lights.Length;
if (nLights == 0)
{
return(Spectrum.Zero);
}
int lightNum;
float lightPdf;
if (!(lightDistribution is null))
{
lightNum = lightDistribution.SampleDiscrete(sampler.Get1D(), out lightPdf, out _);
if (lightPdf == 0f)
{
return(Spectrum.Zero);
}
}