Hi Alberto, With glDrawArrays the driver should treat all the vertex data is independent, and shouldn't care about vertices being cooincident. Using repeared vertices to create zero area triangles is even a trick that one can use to join trip strips together. I would expect this work, and have certainly used this quite recently and it worked fine, at least on my Nvidia/linux laptop where I was doing this testing.
The only area where perhaps the driver could be coming into play might be if the the display listing of the data is resulting in the driver trying to optimize away duplicate data and getting it wrong. I haven't heard of driver problems with zero area triangles so perhaps it'd be worth checking with Nvidia to see if there is a bug report fitting this description. The other route is to check your app and tools to see if the problem isn't being introduced elsewhere, but the symptom only appearing once you send the data to OpenGL to cope with. Robert. On 10/24/06, Alberto Jaspe <[EMAIL PROTECTED]> wrote:
Hello, we have seen that some nvidia cards, with some drivers, and sometimes, break doing a glDrawArrays when any of the triangles has the three vertex in the same place. In our pipeline we use several softwares, and file conversions, and maybe any of those makes this kind of triangles. I need to do a visitor (or maybe a functor) that travel thrugh VertexArrays, and checks triangle's area one by one, removing corresponding index when area is smaller than a threshold. Any little advice or reference would be great ! Thanks in advance, Alberto Jaspe _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
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