Hi Robert, I missed the case that the line segment might start or end in the bbox, and there my modification will introduce a bug. The epsilon in the svn tree is 1E-5 while it was 1E-6 in stable, I will test again and maybe propose a different solution. Regards, Laurens.
On Thu, Mar 12, 2015 at 6:58 PM, Robert Osfield <[email protected]> wrote: > Hi Laurens, > > I'm rejecting this submission as it'll introduce a bug of not rejecting > intersected triangles that are outside the line segment - this code you > have commented out exists for a reason. > > If you are not getting intersections with flat objects then this is bug, > but this is absolutely not the way to fix it. If one is hitting up against > numerical errors then the solution is probably to extend the length of the > line segment being used for testing. There is clamping of the line segment > to bounding volumes, which in the past has caused problems with zero flat > objects aligned to X,Y or Z axis, but there is now an epsilon used in the > intersectAndClip method to handle this evantuality. > > Could it be that your input LineSegment needs to be expanded a little? > > If you would like this issue resolved then you'll need to recreate a test > sample code/data that can reproduce the problem. > > Robert. > > > On 12 March 2015 at 16:29, Voerman, L. <[email protected]> wrote: > >> Hi Robert, >> >> attached is a zip with a modified version of: >> OpenSceneGraph\src\osgUtil\LineSegmentIntersector.cpp >> >> Here in the Netherlands we have some very flat land, and we had some >> problems with the picking >> not returning a hit at all. After a lot of debugging I found out that the >> picker optimizes the >> bounding box for the current object, and rejects the pick if it's outside >> the box. However, when the >> box has height zero a lot of picks get rejected on numeric errors. I >> propose a fix by disableing the >> box test, as I think there is no possibility to generate a hit outside >> the bbox except by rounding errors. >> We acutally have been using this fix with the stable tree for quite some >> time now, but I think it should >> only be merged into the svn tree. >> >> Tested with Visual Studio Express 2013 on 64bit windows 7 >> >> This patch applies the svn tree only, the file in the stable tree has >> some differences. >> >> >> Regards, Laurens Voerman. >> >> >> _______________________________________________ >> osg-submissions mailing list >> [email protected] >> >> http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org >> >> > > _______________________________________________ > osg-submissions mailing list > [email protected] > > http://lists.openscenegraph.org/listinfo.cgi/osg-submissions-openscenegraph.org > >
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