FGFS-4.1/OpenSceneGraph
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Added a small epsilon expansion of the bounding box being clipped/intersected against, to avoid numberic errors causing problems.

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This commit is contained in:
Robert Osfield
2008-08-04 08:45:08 +00:00
parent 268b79d03f
commit fcc8426226
1 changed files with 50 additions and 47 deletions
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97
src/osgUtil/LineSegmentIntersector.cpp
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@@ -287,16 +287,6 @@ void LineSegmentIntersector::intersect(osgUtil::IntersectionVisitor& iv, osg::Dr
if (iv.getDoDummyTraversal()) return;
double epsilon = 1e-8;
if ((s-e).length()<epsilon)
{
osg::Vec3d delta_e_end = _end - e;
osg::Vec3d delta_s_start = _start - s;
double scale = 0.001;
s += (delta_s_start * scale);
e += (delta_e_end * scale);
}
osg::KdTree* kdTree = iv.getUseKdTreeWhenAvailable() ? dynamic_cast<osg::KdTree*>(drawable->getShape()) : 0;
if (kdTree)
{
@@ -460,43 +450,56 @@ bool LineSegmentIntersector::intersects(const osg::BoundingSphere& bs)
return true;
}
bool LineSegmentIntersector::intersectAndClip(osg::Vec3d& s, osg::Vec3d& e,const osg::BoundingBox& bb)
bool LineSegmentIntersector::intersectAndClip(osg::Vec3d& s, osg::Vec3d& e,const osg::BoundingBox& bbInput)
{
osg::Vec3d bb_min(bbInput._min);
osg::Vec3d bb_max(bbInput._max);
#if 1
double epsilon = 1e-4;
bb_min.x() -= epsilon;
bb_min.y() -= epsilon;
bb_min.z() -= epsilon;
bb_max.x() += epsilon;
bb_max.y() += epsilon;
bb_max.z() += epsilon;
#endif
// compate s and e against the xMin to xMax range of bb.
if (s.x()<=e.x())
{
// trivial reject of segment wholely outside.
if (e.x()<bb.xMin()) return false;
if (s.x()>bb.xMax()) return false;
if (e.x()<bb_min.x()) return false;
if (s.x()>bb_max.x()) return false;
if (s.x()<bb.xMin())
if (s.x()<bb_min.x())
{
// clip s to xMin.
s = s+(e-s)*(bb.xMin()-s.x())/(e.x()-s.x());
s = s+(e-s)*(bb_min.x()-s.x())/(e.x()-s.x());
}
if (e.x()>bb.xMax())
if (e.x()>bb_max.x())
{
// clip e to xMax.
e = s+(e-s)*(bb.xMax()-s.x())/(e.x()-s.x());
e = s+(e-s)*(bb_max.x()-s.x())/(e.x()-s.x());
}
}
else
{
if (s.x()<bb.xMin()) return false;
if (e.x()>bb.xMax()) return false;
if (s.x()<bb_min.x()) return false;
if (e.x()>bb_max.x()) return false;
if (e.x()<bb.xMin())
if (e.x()<bb_min.x())
{
// clip s to xMin.
e = s+(e-s)*(bb.xMin()-s.x())/(e.x()-s.x());
e = s+(e-s)*(bb_min.x()-s.x())/(e.x()-s.x());
}
if (s.x()>bb.xMax())
if (s.x()>bb_max.x())
{
// clip e to xMax.
s = s+(e-s)*(bb.xMax()-s.x())/(e.x()-s.x());
s = s+(e-s)*(bb_max.x()-s.x())/(e.x()-s.x());
}
}
@@ -505,36 +508,36 @@ bool LineSegmentIntersector::intersectAndClip(osg::Vec3d& s, osg::Vec3d& e,const
{
// trivial reject of segment wholely outside.
if (e.y()<bb.yMin()) return false;
if (s.y()>bb.yMax()) return false;
if (e.y()<bb_min.y()) return false;
if (s.y()>bb_max.y()) return false;
if (s.y()<bb.yMin())
if (s.y()<bb_min.y())
{
// clip s to yMin.
s = s+(e-s)*(bb.yMin()-s.y())/(e.y()-s.y());
s = s+(e-s)*(bb_min.y()-s.y())/(e.y()-s.y());
}
if (e.y()>bb.yMax())
if (e.y()>bb_max.y())
{
// clip e to yMax.
e = s+(e-s)*(bb.yMax()-s.y())/(e.y()-s.y());
e = s+(e-s)*(bb_max.y()-s.y())/(e.y()-s.y());
}
}
else
{
if (s.y()<bb.yMin()) return false;
if (e.y()>bb.yMax()) return false;
if (s.y()<bb_min.y()) return false;
if (e.y()>bb_max.y()) return false;
if (e.y()<bb.yMin())
if (e.y()<bb_min.y())
{
// clip s to yMin.
e = s+(e-s)*(bb.yMin()-s.y())/(e.y()-s.y());
e = s+(e-s)*(bb_min.y()-s.y())/(e.y()-s.y());
}
if (s.y()>bb.yMax())
if (s.y()>bb_max.y())
{
// clip e to yMax.
s = s+(e-s)*(bb.yMax()-s.y())/(e.y()-s.y());
s = s+(e-s)*(bb_max.y()-s.y())/(e.y()-s.y());
}
}
@@ -543,36 +546,36 @@ bool LineSegmentIntersector::intersectAndClip(osg::Vec3d& s, osg::Vec3d& e,const
{
// trivial reject of segment wholely outside.
if (e.z()<bb.zMin()) return false;
if (s.z()>bb.zMax()) return false;
if (e.z()<bb_min.z()) return false;
if (s.z()>bb_max.z()) return false;
if (s.z()<bb.zMin())
if (s.z()<bb_min.z())
{
// clip s to zMin.
s = s+(e-s)*(bb.zMin()-s.z())/(e.z()-s.z());
s = s+(e-s)*(bb_min.z()-s.z())/(e.z()-s.z());
}
if (e.z()>bb.zMax())
if (e.z()>bb_max.z())
{
// clip e to zMax.
e = s+(e-s)*(bb.zMax()-s.z())/(e.z()-s.z());
e = s+(e-s)*(bb_max.z()-s.z())/(e.z()-s.z());
}
}
else
{
if (s.z()<bb.zMin()) return false;
if (e.z()>bb.zMax()) return false;
if (s.z()<bb_min.z()) return false;
if (e.z()>bb_max.z()) return false;
if (e.z()<bb.zMin())
if (e.z()<bb_min.z())
{
// clip s to zMin.
e = s+(e-s)*(bb.zMin()-s.z())/(e.z()-s.z());
e = s+(e-s)*(bb_min.z()-s.z())/(e.z()-s.z());
}
if (s.z()>bb.zMax())
if (s.z()>bb_max.z())
{
// clip e to zMax.
s = s+(e-s)*(bb.zMax()-s.z())/(e.z()-s.z());
s = s+(e-s)*(bb_max.z()-s.z())/(e.z()-s.z());
}
}