shadow volumes and portals.. anyone ?

[Julien Cayzac]

How can I render proper shadows using shadow volumes inside a portal? If the stencil buffer is used to clip a portal, I can't use it while rendering the portal itself...

Any suggestion?

[NicholasFrancis]

Have you considered using the stencil bit-masks (glStencilMask

I haven't tried this, but you should be able to use one bit for the portal and the remaining 7 for the stencilled shadows...

What exactly are you trying to do?

Good luck,
nich

[ToolTech]

It is quite simple to use recursive stencil masks. Just render your portal stencil e.g. with ref number x and then reder your shadows in your portal with ref values >x.