Attached is a fixed version of OverlayNode.cpp. I fixed CustomPolytope::cut( osg::Plane ) method. Bug was apparent in such scenario:
Let P1 be some random frustum polytope
Let P2 be the polytope that was created from P1 bounding box (P2 contains P1 entirely)
Then ignoring precision errors: P1.cut( P2 ) == P2.cut( P1 ) == P1. But this condition was not always met. Cut failed when some of the polytope reference points happened to lie exactly on some intersecting planes in both P1 & P2 (plane distance was = 0).
I only use CustomPolytope for my shadowing stuff so I did not test how this affects rest of OverlayNode.cpp.
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Also attached is a minor precision improvement for osg::Plane intersect method (double version).
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I have also one observation regarding osg::Plane - There are two intersect vertices methods (float and double flavour):
inline int intersect(const std::vector<Vec3>& vertices) const
inline int intersect(const std::vector<Vec3d>& vertices) const
I guess osg::Plane won't compile when someone changes default vec3 typedef to vec3d. Shouldn't the first method be changed to use vec3f explicitly ? Ie:
inline int intersect(const std::vector<Vec3f>& vertices) const"
to bugfixes in osg::Polytope.setToUnitFrustum and setToBoundingBox It was
sent at beginning of december. I read it when purging my Thrash emails and
found it there this because it was wrongly classified as SPAM.
What stroke me in this email was the fact that there was once an error in
Polytope class. Since I adopted CustomPolytope (osgSim OverlayNode.cpp) for
my minimal shadow area computations I checked my code for this error. And I
found it in CustomPolytope::setToUnitFrustum method.
CustomPolytope::setToBoundingBox seemed OK.
So I went back to the origin and fixed this error in OverlayNode.cpp as
well. I have not tested it in OverlayNode though (I don't know how) so
please look at this carefully. But it seems to work fine with my shadow
calculations."
of the OverlayNode.
I change the overlay subgraph dynamically and when I remove all the
subgraph nodes that is inside the current main camera FOV (others
outside still exist), the overlay texture does not update because of the
early return in the traversal. I then get a kind of ghost texture moving
around the terrain.
The attached file fixed the problem for me, but I'm not sure if it is
the best way to address the problem."
if continuous updating is set to false.
The problem was being caused by the camera update call never being made
if continuous updating was not set to true. This fix adds a flag that
is set when dirtyOverlayTexture() is called and checked in the update
visitor section of the traversal to determine if the camera should be
updated.
I tested the fix by making some changes to the osgAnimate example
program so it has continuous updating off and calls dirtyOverlayTexture
for each frame. The overlay texture now displays properly."
