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tolerance to triangle intersection

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This commit is contained in:
mattijs
2009-04-07 13:49:33 +01:00
parent deb7abdd4d
commit 1f19d13b5a
2 changed files with 48 additions and 82 deletions
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7
src/OpenFOAM/meshes/primitiveShapes/triangle/triangle.H
View File

@ -169,12 +169,15 @@ public:
//- Fast intersection with a ray.
// For a hit, the pointHit.distance() is the line parameter t :
// intersection=p+t*q. Only defined for VISIBLE, FULL_RAY or
// HALF_RAY.
// HALF_RAY. tol increases the virtual size of the triangle
// by a relative factor - can be used to compensate for
// limited precision.
inline pointHit intersection
(
const point& p,
const vector& q,
const intersection::algorithm alg
const intersection::algorithm alg,
const scalar tol = 0.0
) const;
//- Return nearest point to p on triangle

123
src/OpenFOAM/meshes/primitiveShapes/triangle/triangleI.H
View File

@ -439,7 +439,8 @@ inline pointHit triangle<Point, PointRef>::intersection
(
const point& orig,
const vector& dir,
const intersection::algorithm alg
const intersection::algorithm alg,
const scalar tol
) const
{
const vector edge1 = b_ - a_;
@ -457,99 +458,61 @@ inline pointHit triangle<Point, PointRef>::intersection
if (alg == intersection::VISIBLE)
{
// Culling branch
if (det < SMALL)
if (det < ROOTVSMALL)
{
// return miss
// Ray on wrong side of triangle. Return miss
return intersection;
}
/* calculate distance from a_ to ray origin */
const vector tVec = orig-a_;
/* calculate U parameter and test bounds */
scalar u = tVec & pVec;
if (u < 0.0 || u > det)
{
// return miss
return intersection;
}
/* prepare to test V parameter */
const vector qVec = tVec ^ edge1;
/* calculate V parameter and test bounds */
scalar v = dir & qVec;
if (v < 0.0 || u + v > det)
{
// return miss
return intersection;
}
/* calculate t, scale parameters, ray intersects triangle */
scalar t = edge2 & qVec;
scalar inv_det = 1.0 / det;
t *= inv_det;
u *= inv_det;
v *= inv_det;
intersection.setHit();
intersection.setPoint(a_ + u*edge1 + v*edge2);
intersection.setDistance(t);
}
else if (alg == intersection::HALF_RAY || alg == intersection::FULL_RAY)
{
// Non-culling branch
if (det > -SMALL && det < SMALL)
if (det > -ROOTVSMALL && det < ROOTVSMALL)
{
// return miss
// Ray parallel to triangle. Return miss
return intersection;
}
const scalar inv_det = 1.0 / det;
/* calculate distance from a_ to ray origin */
const vector tVec = orig - a_;
/* calculate U parameter and test bounds */
const scalar u = (tVec & pVec)*inv_det;
if (u < 0.0 || u > 1.0)
{
// return miss
return intersection;
}
/* prepare to test V parameter */
const vector qVec = tVec ^ edge1;
/* calculate V parameter and test bounds */
const scalar v = (dir & qVec) * inv_det;
if (v < 0.0 || u + v > 1.0)
{
// return miss
return intersection;
}
/* calculate t, ray intersects triangle */
const scalar t = (edge2 & qVec) * inv_det;
if (alg == intersection::HALF_RAY && t < 0)
{
// return miss
return intersection;
}
intersection.setHit();
intersection.setPoint(a_ + u*edge1 + v*edge2);
intersection.setDistance(t);
}
else
const scalar inv_det = 1.0 / det;
/* calculate distance from a_ to ray origin */
const vector tVec = orig-a_;
/* calculate U parameter and test bounds */
const scalar u = (tVec & pVec)*inv_det;
if (u < -tol || u > 1.0+tol)
{
FatalErrorIn
(
"triangle<Point, PointRef>::intersection(const point&"
", const vector&, const intersection::algorithm)"
) << "intersection only defined for VISIBLE, FULL_RAY or HALF_RAY"
<< abort(FatalError);
// return miss
return intersection;
}
/* prepare to test V parameter */
const vector qVec = tVec ^ edge1;
/* calculate V parameter and test bounds */
const scalar v = (dir & qVec) * inv_det;
if (v < -tol || u + v > 1.0+tol)
{
// return miss
return intersection;
}
/* calculate t, scale parameters, ray intersects triangle */
const scalar t = (edge2 & qVec) * inv_det;
if (alg == intersection::HALF_RAY && t < -tol)
{
// Wrong side of orig. Return miss
return intersection;
}
intersection.setHit();
intersection.setPoint(a_ + u*edge1 + v*edge2);
intersection.setDistance(t);
return intersection;
}