bool Foam::octreeDataBoundBox::findTightest
(
const label index,
const point& sample,
treeBoundBox& tightest
) const
{
// Get furthest away vertex
point myNear, myFar;
allBb_[index].calcExtremities(sample, myNear, myFar);
const point dist = myFar - sample;
scalar myFarDist = mag(dist);
point tightestNear, tightestFar;
tightest.calcExtremities(sample, tightestNear, tightestFar);
scalar tightestFarDist = mag(tightestFar - sample);
if (tightestFarDist < myFarDist)
{
// Keep current tightest.
return false;
}
else
{
// Construct bb around sample and myFar
const point dist2(fabs(dist.x()), fabs(dist.y()), fabs(dist.z()));
tightest.min() = sample - dist2;
tightest.max() = sample + dist2;
return true;
}
}
bool Foam::treeLeaf<Foam::octreeDataPoint>::findNearest
(
const octreeDataPoint& shapes,
const point& sample,
treeBoundBox& tightest,
label& tightestI,
scalar& tightestDist
) const
{
// Some aliases
const pointField& points = shapes.points();
point& tMin = tightest.min();
point& tMax = tightest.max();
scalar minDist2 = sqr(tightestDist);
label minIndex = -1;
forAll(indices_, i)
{
label pointi = indices_[i];
scalar dist = magSqr(points[pointi] - sample);
if (dist < minDist2)
{
minDist2 = dist;
minIndex = pointi;
}
}
bool Foam::treeLeaf<Foam::octreeDataTriSurface>::findNearest
(
const octreeDataTriSurface& shapes,
const point& sample,
treeBoundBox& tightest,
label& tightestI,
scalar& tightestDist
) const
{
// Some aliases
const treeBoundBoxList& allBb = shapes.allBb();
point& min = tightest.min();
point& max = tightest.max();
point nearest;
bool changed = false;
forAll(indices_, i)
{
label faceI = indices_[i];
// Quick rejection test.
if (tightest.overlaps(allBb[faceI]))
{
// Full calculation
scalar dist = shapes.calcNearest(faceI, sample, nearest);
if (dist < tightestDist)
{
// Update bb (centered around sample, span is dist)
min.x() = sample.x() - dist;
min.y() = sample.y() - dist;
min.z() = sample.z() - dist;
max.x() = sample.x() + dist;
max.y() = sample.y() + dist;
max.z() = sample.z() + dist;
tightestI = faceI;
tightestDist = dist;
changed = true;
}
}
}
void Foam::treeDataPoint::findNearestOp::operator()
(
const labelUList& indices,
const linePointRef& ln,
treeBoundBox& tightest,
label& minIndex,
point& linePoint,
point& nearestPoint
) const
{
const treeDataPoint& shape = tree_.shapes();
// Best so far
scalar nearestDistSqr = GREAT;
if (minIndex >= 0)
{
nearestDistSqr = magSqr(linePoint - nearestPoint);
}
forAll(indices, i)
{
const label index = indices[i];
label pointi =
(
shape.useSubset()
? shape.pointLabels()[index]
: index
);
const point& shapePt = shape.points()[pointi];
if (tightest.contains(shapePt))
{
// Nearest point on line
pointHit pHit = ln.nearestDist(shapePt);
scalar distSqr = sqr(pHit.distance());
if (distSqr < nearestDistSqr)
{
nearestDistSqr = distSqr;
minIndex = index;
linePoint = pHit.rawPoint();
nearestPoint = shapePt;
{
point& minPt = tightest.min();
minPt = min(ln.start(), ln.end());
minPt.x() -= pHit.distance();
minPt.y() -= pHit.distance();
minPt.z() -= pHit.distance();
}
{
point& maxPt = tightest.max();
maxPt = max(ln.start(), ln.end());
maxPt.x() += pHit.distance();
maxPt.y() += pHit.distance();
maxPt.z() += pHit.distance();
}
}
}
}
}
// Intersect triangle with bounding box. Return true if
// any of the faces of bb intersect triangle.
// Note: so returns false if triangle inside bb.
bool Foam::triangleFuncs::intersectBb
(
const point& p0,
const point& p1,
const point& p2,
const treeBoundBox& cubeBb
)
{
const vector p10 = p1 - p0;
const vector p20 = p2 - p0;
// cubeBb points; counted as if cell with vertex0 at cubeBb.min().
const point& min = cubeBb.min();
const point& max = cubeBb.max();
const point& cube0 = min;
const point cube1(min.x(), min.y(), max.z());
const point cube2(max.x(), min.y(), max.z());
const point cube3(max.x(), min.y(), min.z());
const point cube4(min.x(), max.y(), min.z());
const point cube5(min.x(), max.y(), max.z());
const point cube7(max.x(), max.y(), min.z());
//
// Intersect all 12 edges of cube with triangle
//
point pInter;
pointField origin(4);
// edges in x direction
origin[0] = cube0;
origin[1] = cube1;
origin[2] = cube5;
origin[3] = cube4;
scalar maxSx = max.x() - min.x();
if (intersectAxesBundle(p0, p10, p20, 0, origin, maxSx, pInter))
{
return true;
}
// edges in y direction
origin[0] = cube0;
origin[1] = cube1;
origin[2] = cube2;
origin[3] = cube3;
scalar maxSy = max.y() - min.y();
if (intersectAxesBundle(p0, p10, p20, 1, origin, maxSy, pInter))
{
return true;
}
// edges in z direction
origin[0] = cube0;
origin[1] = cube3;
origin[2] = cube7;
origin[3] = cube4;
scalar maxSz = max.z() - min.z();
if (intersectAxesBundle(p0, p10, p20, 2, origin, maxSz, pInter))
{
return true;
}
// Intersect triangle edges with bounding box
if (cubeBb.intersects(p0, p1, pInter))
{
return true;
}
if (cubeBb.intersects(p1, p2, pInter))
{
return true;
}
if (cubeBb.intersects(p2, p0, pInter))
{
return true;
}
return false;
}
