public Point3D OffsetRayOrigin(Vector3D pError, Normal3D n, Vector3D w)
{
double d = n.Abs().Dot(pError);
// We have tons of precision; for now bump up the offset a bunch just
// to be extra sure that we start on the right side of the surface
// (In case of any bugs in the epsilons code...)
d *= 1024.0;
Point3D offset = d * n.ToPoint3D();
if (w.Dot(n) < 0.0)
{
offset = -offset;
}
Point3D po = this + offset;
// Round offset point _po_ away from _p_
for (int i = 0; i < 3; ++i)
{
if (offset[i] > 0.0)
{
po[i] = PbrtMath.NextFloatUp(po[i]);
}
else if (offset[i] < 0.0)
{
po[i] = PbrtMath.NextFloatDown(po[i]);
}
}
return(po);
}
public static Normal3D Max(Normal3D a, Normal3D b)
{
return(new Normal3D(Math.Max(a.X, b.X), Math.Max(a.Y, b.Y), Math.Max(a.Z, b.Z)));
}
public Normal3D FaceForward(Normal3D n2)
{
return((Dot(n2) < 0.0) ? -this : this);
}
public double AbsDot(Normal3D b)
{
return(Math.Abs(Dot(b)));
}
public double Dot(Normal3D b)
{
return(X * b.X + Y * b.Y + Z * b.Z);
}
public Normal3D AddScaled(Normal3D b, double scale)
{
return(new Normal3D(X + scale * b.X, Y + scale * b.Y, Z + scale * b.Z));
}
public Vector3D FaceForward(Normal3D n)
{
return((Dot(n) < 0.0) ? -this : this);
}
public Vector3D Cross(Normal3D b)
{
return(new Vector3D(Y * b.Z - Z * b.Y, Z * b.X - X * b.Z, X * b.Y - Y * b.X));
}