Re: [Plib-users] ssgRoot node

[Curtis L. O. <cu...@fl...>]

Steve Baker writes:
> That was the *original* intention when I wrote SSG - however, the system
> works reasonably well when you have multiple roots and multiple calls to
> ssgCullAndDraw in a single frame.
> 
> The thing you lose is the ability to sort by transparency.
>
> Each call to ssgCullAndDraw sorts it's polygons into translucent and opaque
> bins so that translucent surfaces can be rendered last.  If you have two
> calls, then the translucent polygons in the first scene graph will be
> drawn before the opaque polygons of the second.

Note: to avoid confusion, as far as I know, plib can separate out the
opaque geometry from the translucent geometry and draw them in
separate passes.  However, plib cannot sort the translucent polygons
back to front (and patches submitted to optionally do this have been
explicitely rejected.)

Regards,

Curt.
-- 
Curtis Olson   HumanFIRST Program               FlightGear Project
Twin Cities    curt 'at' me.umn.edu             curt 'at' flightgear.org
Minnesota      http://www.menet.umn.edu/~curt   http://www.flightgear.org