private Vector3D GetColor(Ray r, HittableList world, int depth)
{
HitRecord rec;
if (world.Hit(r, 0.001, double.MaxValue, out rec))
{
Ray scattered;
Vector3D attenuation;
if (depth < 50 && rec.matPtr.Scatter(r, rec, out attenuation, out scattered)) //只递归50次，避免无谓的性能浪费
{
Vector3D color = GetColor(scattered, world, depth + 1); //每次光线衰减之后深度加一
return(new Vector3D(attenuation.X * color.X, attenuation.Y * color.Y, attenuation.Z * color.Z));
}
else
{
return(new Vector3D(0, 0, 0));
}
}
else
{
Vector3D unitDirection = r.Direction.UnitVector();
double t = 0.5 * (unitDirection.Y + 1);
return((1 - t) * new Vector3D(1, 1, 1) + t * new Vector3D(0.5, 0.7, 1));
}
}
private Vector3D GetColor(Ray r, HittableList world)
{
HitRecord rec;
if (world.Hit(r, 0, double.MaxValue, out rec))
{
return(0.5 * new Vector3D(rec.normal.X + 1, rec.normal.Y + 1, rec.normal.Z + 1));
}
else
{
Vector3D unitDirection = r.Direction.UnitVector();
double t = 0.5 * (unitDirection.Y + 1);
return((1 - t) * new Vector3D(1, 1, 1) + t * new Vector3D(0.5, 0.7, 1));
}
}
private Vector3D GetColor(Ray r, HittableList world)
{
HitRecord rec;
if (world.Hit(r, 0.0000001, double.MaxValue, out rec))
{
Vector3D target = rec.p + rec.normal + RandomInUnitShpere( ); //击中点加法线向量得到击中点单位球的球心，球心加上
//随机向量得到反射的方向。
return(0.5 * GetColor(new Ray(rec.p, target - rec.p), world)); //每次碰撞都使光线强度减半
}
else
{
Vector3D unitDirection = r.Direction.UnitVector();
double t = 0.5 * (unitDirection.Y + 1);
return((1 - t) * new Vector3D(1, 1, 1) + t * new Vector3D(0.5, 0.7, 1));
}
}
