Hello Andrew,
I am trying to implement something like this, in order to compute hit
tests on a line. I don't need to know which objects intersected the
line, or get a list of objects/intersections out, just need to know "Is
there an intersection or not".
The original posts are included below. Would anyone know how I might go
about implementing this?
I think I had mentioned the files to check in that thread, but if not,
have a look at the code in osgUtil::IntersectionVisitor,
osgUtil::LineSegmentIntersector and associated classes (some of which
are in the source files only). It should be pretty simple to use those
as guidance and just return true whenever it can be decided without
error that the intersection will succeed. Also if you remove all the
calculations that are done in the case an intersection was successful
(node path copy, local intersection point and normal, etc.) you might
gain a bit too.
Note that if you can survive by doing an approximate test, then you
could also implement your own subclasses of
LineSegmentIntersector/IntersectionVisitor that would only check
bounding volumes. That would be much quicker than testing the geometry.
If you do need exact tests, then make sure you enable kd-trees for your
geometries, this will help greatly.
If you end up doing this, please do it in a way that can be
re-integrated into OSG since I expect other people will be interested in
using this kind of test.
Hope this helps,
J-S
--
______________________________________________________
Jean-Sebastien Guay [email protected]
http://www.cm-labs.com/
http://whitestar02.webhop.org/
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