private Vector3D GetColor(Ray r, HitableList world, Hitable lightShape, int depth)
{
HitRecord hRec;
/*这里的0.001不能改为0，当tmin设0的时候会导致，遍历hitlist时候，ray的t求解出来是0，
* hit的时候全走了else，导致递归到50层的时候，最后return的是0，* attenuation结果还是0。
* 距离越远，散射用到random_in_unit_sphere生成的ray误差越大
*/
if (world.Hit(r, 0.001f, float.MaxValue, out hRec))
{
ScatterRecord sRec;
Vector3D emitted = hRec.matPtr.Emitted(r, hRec, hRec.u, hRec.v, hRec.p);
if (depth < 50 && hRec.matPtr.Scatter(r, hRec, out sRec))
{
if (sRec.isSpecular)
{
Vector3D c = GetColor(sRec.specularRay, world, lightShape, depth + 1);
return(new Vector3D(sRec.attenuation.X * c.X, sRec.attenuation.Y * c.Y, sRec.attenuation.Z * c.Z));
}
PDF p;
if (lightShape != null)
{
HitablePDF p0 = new HitablePDF(lightShape, hRec.p);
p = new MixturePDF(p0, sRec.pdfPtr);
((MixturePDF)p).MixRatio = scene.MixRatio;
}
else
{
p = sRec.pdfPtr;
}
//CosinePDF p = new CosinePDF(hRec.normal);
Ray scattered = new Ray(hRec.p, p.Generate(), r.Time);
float pdfVal = p.Value(scattered.Direction);
Vector3D color = GetColor(scattered, world, lightShape, depth + 1); //每次光线衰减之后深度加一
return(emitted + hRec.matPtr.ScatteringPDF(r, hRec, scattered)
* new Vector3D(sRec.attenuation.X * color.X, sRec.attenuation.Y
* color.Y, sRec.attenuation.Z * color.Z) / pdfVal);
}
else
{
return(emitted);
}
}
else
{
if (isSky)
{
Vector3D unitDirection = r.Direction.UnitVector();
float t = 0.5f * (unitDirection.Y + 1f);
return((1 - t) * new Vector3D(1, 1, 1) + t * new Vector3D(0.5f, 0.7f, 1));
}
return(new Vector3D(0, 0, 0));
}
}
private Vector3D GetColor(Ray r, HitableList world, int depth)
{
HitRecord rec;
/*这里的0.001不能改为0，当tmin设0的时候会导致，遍历hitlist时候，ray的t求解出来是0，
* hit的时候全走了else，导致递归到50层的时候，最后return的是0，* attenuation结果还是0。
* 距离越远，散射用到random_in_unit_sphere生成的ray误差越大
*/
if (world.Hit(r, 0.001f, float.MaxValue, out rec))
{
Ray scattered;
Vector3D emitted = rec.matPtr.Emitted(r, rec, rec.u, rec.v, rec.p);
Vector3D albedo;
float pdfVal;
if (depth < 50 && rec.matPtr.Scatter(r, rec, out albedo, out scattered, out pdfVal))
{
Hitable lightSphape = new XZRect(213, 343, 227, 332, 554, new Lambertian());
HitablePDF p0 = new HitablePDF(lightSphape, rec.p);
CosinePDF p1 = new CosinePDF(rec.normal);
MixturePDF p = new MixturePDF(p0, p1);
scattered = new Ray(rec.p, p.Generate(), r.Time);
pdfVal = p.Value(scattered.Direction);
Vector3D color = GetColor(scattered, world, depth + 1); //每次光线衰减之后深度加一
return(emitted + rec.matPtr.ScatteringPDF(r, rec, scattered)
* new Vector3D(albedo.X * color.X, albedo.Y * color.Y, albedo.Z * color.Z) / pdfVal);
}
else
{
return(emitted);
}
}
else
{
//Vector3D unitDirection = r.Direction.UnitVector();
//float t = 0.5f * (unitDirection.Y + 1f);
//return (1 - t) * new Vector3D(1, 1, 1) + t * new Vector3D(0.5f, 0.7f, 1);
return(new Vector3D(0, 0, 0));
}
}
