public DifferentialGeometry(Point point, Vector dpdu, Vector dpdv,
Normal dndu, Normal dndv, float u, float v, Shape shape)
{
Point = point;
Normal = (Normal) Vector.Normalize(Vector.Cross(dpdu, dpdv));
DpDu = dpdu;
DpDv = dpdv;
DnDu = dndu;
DnDv = dndv;
U = u;
V = v;
Shape = shape;
if (shape != null && shape.ReverseOrientation != shape.TransformSwapsHandedness)
Normal *= -1.0f;
}
public static AreaLight MakeAreaLight(string name, Transform lightToWorld,
ParamSet parameters, Shape shape)
{
switch (name)
{
case "area":
case "diffuse":
{
var l = parameters.FindSpectrum("L", new Spectrum(1.0f));
var scale = parameters.FindSpectrum("scale", new Spectrum(1.0f));
var numSamples = parameters.FindInt32("nsamples", 1);
return new DiffuseAreaLight(lightToWorld, l * scale, numSamples, shape);
}
default:
throw new ArgumentException("Unknown area light: " + name);
}
}
public DiffuseAreaLight(Transform lightToWorld, Spectrum lemit, int numSamples, Shape shape)
: base(lightToWorld, numSamples)
{
}
public GeometricPrimitive(Shape shape, Material material, AreaLight areaLight)
{
_shape = shape;
_material = material;
_areaLight = areaLight;
}