Thoughts on Stencil not working on NVidia

[Baker]

[Spike]

if glGetIntegerv(GL_STENCIL_BITS) is returning 0, then you messed up your context creation.
commonly your depth+stencil buffers are a single buffer 24.8.
of course, gl treats them separately which results in some fun...
some hardware actually supports 32bit depth buffers!...
but of course, depth+stencil buffer then means that this then means that you have 0bit stencil buffers.

so make sure you're actually requesting a stencil buffer at context creation.

that's my guess.

[Baker]

[mh]

Modern hardware should be able to support 32-bit depth with stencil in it's own buffer, so it would probably also depend on which NV it was failing on.

In truth 24/8 is the format that's most likely to work on everything, so it's the safest default.

Another way of drawing sky is, IIRC, to draw all the sky polys with colormask 0 and depthmask 1, then draw a sky box or sphere with z-fail, depthrange 1,1 and depthmask 0, then draw everything else, which will ensure that sky is only where it should be. Z-fail is not particularly hardware-friendly though, but this way doesn't require stencil at all.

The best way is of course to just draw the sky polys in-place with a shader.

[Baker]

I have the ability to draw mirrors, so I can't control when in the rendering it will draw the sky. At least not for the mirror.

And for fairness purposes, since I can't control when I draw the sky for the mirror, I made it so the sky gets drawn a bit later and should Z-fail to catch things like this problem without any rendering issues only cropping up when mirrors are visible (I mean, what uses mirrors? Nothing currently, hehe. So if I want the feature to work, I want the general usage of non-mirrors to fail so the mirrors feature can be trusted. )

There is the chance that I'm not zfailing the sky on NVidia somehow.

Because on bugged screenshots, the sky is stomping foreground brushes/surfaces.

I will find out what is doing this. Perhaps I may solve in the next 2 days. I mostly need to have the hardware available because every Windows and Mac I have is either ATI or Intel.

[ericw]

I have two laptops with NVidia (9400m, 650GT) I can offer for testing if you need it.

With the Dec 24 OSX build, sky looks fine, but if I set r_oldwater to 0, liquids are rendered solid white. Not sure if that is related or a different issue.

[Baker]

[ericw]

This was solved, right? Was it due to not clearing the stencil buffer at the start of sky drawing, or interference from the shadow code?

[Baker]

[ericw]