[osg-users] normal vectors aren't causing culling

[Robert Osfield]

Hi Jim, Paul et. al,

On Sat, Nov 28, 2009 at 4:32 PM, Paul Martz <pmartz at skew-matrix.com> wrote:
> Right. OSG does not do _face_ culling (culling of individual primitives)
> based on the normal.
>
> However, OSG can do _Drawable_ culling based on a normal. This is how VPB
> databases cull away the back half of the planet. There is a custom cull
> callback (in osgTerrain, I think) that does this. You need to explicitly
> attach it; OSG doesn't use it by default.

Just for clarity, the form of culling that Paul is talking about here
is a technique called cluster culling in graphics literature.  On the
OSG side it's called osg::ClusterCullingCallback.

Robert.