Re: [Quesa-develop] TriMesh colours going to the wrong face

[Tom S. <to...@as...>]

>When the view orientation is such that some faces of a cube lie in a
>plane exactly perpendicular to the window plane, Quesa seems to have
>trouble matching the correct colour specified to the face.

>Hmm, does the problem vary depending on the viewing angle? I.e., if you
>rotate the cube it appears to work at some angles but not others?

Yes. The problem always occured (colours
swapping back and forth between the faces) at angles where a face was in
a plane perpendicular to the screen. Other angles (eg. an 'isometric view')
were much more stable.

I have done more experimenting and have found 2 workarounds:

1) Turning Backface Culling off
2) Use a triMesh cube with 24 vertices, four per face
I had been using 8 vertices for (I had assumed) max. efficiency.

In testing I found that using the 24-vertex trimeshes made no
difference whatsoever to the frame rate over using 8-vertex trimeshes,
so for my purposes, this workaround is perfect.


>Could you extract the cube into a 3DMF model that can be loaded up into
>Geom Test? That would be of great help in debugging it, as we can then
>look at just the geometry independently of anything else that's been
>submitted.

>If you could log a bug with these details, it can go on the todo list to
>look at.

Ok, would you still like the bug to be logged in light of the
two work-arounds suggested above?

Tom