public bool IntersectP(Ray ray, out double hitt0, out double hitt1)
{
double t0 = 0, t1 = ray.TMax;
for (int i = 0; i < 3; ++i)
{
// Update interval for _i_th bounding box slab
double invRayDir = 1 / ray.Direction[i];
double tNear = (MinPoint[i] - ray.Origin[i]) * invRayDir;
double tFar = (MaxPoint[i] - ray.Origin[i]) * invRayDir;
// Update parametric interval from slab intersection $t$ values
if (tNear > tFar)
{
double temp = tNear;
tNear = tFar;
tFar = temp;
}
// Update _tFar_ to ensure robust ray--bounds intersection
tFar *= 1 + 2 * PbrtMath.Gamma(3);
t0 = tNear > t0 ? tNear : t0;
t1 = tFar < t1 ? tFar : t1;
if (t0 > t1)
{
hitt0 = 0.0;
hitt1 = 0.0;
return(false);
}
}
hitt0 = t0;
hitt1 = t1;
return(true);
}
public Point3D ExecuteTransform(Point3D p, out Vector3D pError)
{
double x = p.X, y = p.Y, z = p.Z;
// Compute transformed coordinates from point _pt_
double xp = M[0, 0] * x + M[0, 1] * y + M[0, 2] * z + M[0, 3];
double yp = M[1, 0] * x + M[1, 1] * y + M[1, 2] * z + M[1, 3];
double zp = M[2, 0] * x + M[2, 1] * y + M[2, 2] * z + M[2, 3];
double wp = M[3, 0] * x + M[3, 1] * y + M[3, 2] * z + M[3, 3];
// Compute absolute error for transformed point
double xAbsSum = (Math.Abs(M[0, 0] * x) + Math.Abs(M[0, 1] * y) +
Math.Abs(M[0, 2] * z) + Math.Abs(M[0, 3]));
double yAbsSum = (Math.Abs(M[1, 0] * x) + Math.Abs(M[1, 1] * y) +
Math.Abs(M[1, 2] * z) + Math.Abs(M[1, 3]));
double zAbsSum = (Math.Abs(M[2, 0] * x) + Math.Abs(M[2, 1] * y) +
Math.Abs(M[2, 2] * z) + Math.Abs(M[2, 3]));
pError = PbrtMath.Gamma(3) * new Vector3D(xAbsSum, yAbsSum, zAbsSum);
//CHECK_NE(wp, 0);
if (wp == 1.0)
{
return(new Point3D(xp, yp, zp));
}
else
{
return(new Point3D(xp, yp, zp) / wp);
}
}
public bool IntersectP(Ray ray, Vector3D invDir, bool[] dirIsNeg)
{
// Check for ray intersection against $x$ and $y$ slabs
double tMin = (this[dirIsNeg[0] ? 1 : 0].X - ray.Origin.X) * invDir.X;
double tMax = (this[dirIsNeg[0] ? 0 : 1].X - ray.Origin.X) * invDir.X;
double tyMin = (this[dirIsNeg[1] ? 1 : 0].Y - ray.Origin.Y) * invDir.Y;
double tyMax = (this[dirIsNeg[1] ? 0 : 1].Y - ray.Origin.Y) * invDir.Y;
// Update _tMax_ and _tyMax_ to ensure robust bounds intersection
tMax *= 1.0 + 2.0 * PbrtMath.Gamma(3);
tyMax *= 1.0 + 2.0 * PbrtMath.Gamma(3);
if (tMin > tyMax || tyMin > tMax)
{
return(false);
}
if (tyMin > tMin)
{
tMin = tyMin;
}
if (tyMax < tMax)
{
tMax = tyMax;
}
// Check for ray intersection against $z$ slab
double tzMin = (this[dirIsNeg[2] ? 1 : 0].Z - ray.Origin.Z) * invDir.Z;
double tzMax = (this[dirIsNeg[2] ? 0 : 1].Z - ray.Origin.Z) * invDir.Z;
// Update _tzMax_ to ensure robust bounds intersection
tzMax *= 1.0 + 2.0 * PbrtMath.Gamma(3);
if (tMin > tzMax || tzMin > tMax)
{
return(false);
}
if (tzMin > tMin)
{
tMin = tzMin;
}
if (tzMax < tMax)
{
tMax = tzMax;
}
return((tMin < ray.TMax) && (tMax > 0.0));
}
