when experimenting with the 3DCoreSim, I observed the following: When switching the model to "wireframe cube" and rotating it automatically or by hand, some definitely invisible faces are not discarded properly. Then sometimes they ARE discarded.

Is that proper behaviour, or just a problem with the normals, or an actual bug? If it were a bug, this would effectively impact the performance since invisible faces would still render to the screen before being rendered over by frontmost pixels. When watching the wirframe sphere you can also see that there are definitely invisible faces not being discarded. The other models are too complex so I can't see it very well.

What do you think?

- Claudio

Hi Claudio,

Depending on the model its sometimes needed not to remove some back facing surfaces which are close ton the visible edge. Depending on how your backfacing algorithm works for certain types of complex models you can sometimes see parts of halve backfacing surfaces. Therefore the backfacing code which is used in the DEMO allows setting a "safety-margin" of backfacing percentage to allow surfaces on the "edge" to be recognized as backfacing but still be drawn.
The demo code was just setting this safety margin relative high.

BTW the demo that you saw is relative old we have newer 3D support libraries now which work slightly different - but we did not yet prepare another simulator release.

Cheers

Btw, have you already looked at my proposals for some new AA behaviour (and more!) under Features/"Economy" 4x Antialiasing? I would be glad to hear your opinion about my ideas. Maybe one of them could actually be realized?

Regards,
Claudio

PS: I'll try to have a look at the economy anti-aliasing too.