public override Spectrum SampleL(Point p, double pEpsilon, LightSample ls, double time, ref Vector wi, ref double pdf, ref VisibilityTester visibility)
{
wi = new Vector (LightDir);
pdf = 1.0;
visibility.SetRay (p, pEpsilon, wi, time);
return L;
}
public override Spectrum SampleL(Scene scene, LightSample ls, double u1, double u2, double time, ref Ray ray, ref Normal Ns, ref double pdf)
{
Point org = ShapeSet.Sample (ls, ref Ns);
Vector dir = MonteCarlo.UniformSampleSphere (u1, u2);
if ((dir ^ Ns) < 0.0)
dir *= -1.0;
ray = new Ray (org, dir, 0.001, double.PositiveInfinity, time);
pdf = ShapeSet.Pdf (org) * Util.InvTwoPi;
Spectrum Ls = L (org, Ns, dir);
return Ls;
}
public override Spectrum SampleL(Point p, double pEpsilon, LightSample ls, double time, ref Vector wi, ref double pdf, ref VisibilityTester visibility)
{
Normal ns = new Normal ();
Point ps = ShapeSet.Sample (p, ls, ref ns);
wi = (ps - p).Normalized;
pdf = ShapeSet.Pdf (p, wi);
visibility.SetSegment (p, pEpsilon, ps, 0.001, time);
Spectrum Ls = L (ps, ns, -wi);
return Ls;
}
public Point Sample(Point p, LightSample lightSample, ref Normal Ns)
{
double temp = 0.0;
int sn = AreaDistribution.SampleDiscrete (lightSample.uComponent, ref temp);
Point pt = Shapes[sn].Sample (p, lightSample.uPos[0], lightSample.uPos[1], ref Ns);
// Find closest intersection of ray with shapes in _ShapeSet_
Ray r = new Ray (p, pt - p, 0.001, double.PositiveInfinity);
double rayEps = 0.0, thit = 1.0;
bool anyHit = false;
DifferentialGeometry dg = new DifferentialGeometry ();
foreach (IShape shape in Shapes)
anyHit |= shape.Intersect (r, ref thit, ref rayEps, ref dg);
if (anyHit)
Ns = new Normal (dg.n);
return r.Apply (thit);
}
public override Spectrum SampleL(Scene scene, LightSample ls, double u1, double u2, double time, ref Ray ray, ref Normal Ns, ref double pdf)
{
// Choose point on disk oriented toward infinite light direction
Point worldCenter;
double worldRadius;
scene.WorldBound.BoundingSphere (out worldCenter, out worldRadius);
Vector v1, v2;
Util.CoordinateSystem (LightDir, out v1, out v2);
double d1 = 0.0, d2 = 0.0;
MonteCarlo.ConcentricSampleDisk (ls.uPos[0], ls.uPos[1], ref d1, ref d2);
Point Pdisk = worldCenter + worldRadius * (d1 * v1 + d2 * v2);
// Set ray origin and direction for infinite light ray
ray = new Ray (Pdisk + worldRadius * LightDir, -LightDir, 0.0, double.PositiveInfinity, time);
Ns = new Normal (ray.Direction);
pdf = 1.0 / (Util.Pi * worldRadius * worldRadius);
return L;
}
public Point Sample(LightSample lightSample, ref Normal Ns)
{
double temp = 0.0;
int sn = AreaDistribution.SampleDiscrete (lightSample.uComponent, ref temp);
return Shapes[sn].Sample (lightSample.uPos[0], lightSample.uPos[1], ref Ns);
}
public abstract Spectrum SampleL(Scene scene, LightSample ls, double u1, double u2, double time, ref Ray ray, ref Normal Ns, ref double pdf);
public abstract Spectrum SampleL(Point p, double pEpsilon, LightSample ls, double time, ref Vector wi, ref double pdf, ref VisibilityTester visibility);
