Re: [Plib-users] Performance Benchmarks

[Steve B. <sjb...@ai...>]

> Aaron Drew wrote:
> 
> I'm just wondering if any performance benchmarks have been done with plib?

No - when I first wrote it, the overheads in PLIB were *negligable* compared to the
time consumed in OpenGL doing vertex transforms - so there wasn't much point in leaning
on the optimisation.

Now we have hardware T&L, it would be interesting to see where the cycles are going.

Informal testing I've done at work suggest that even with a GeForce-2, providing you
have an 'equivelently modern' CPU (say a 450MHz or so), PLIB is still not the bottleneck.

> From the website its hard to see if plib comes with any standard visibility algorithm support
> like portals, bsp trees or octrees.

No portals - although it would be moderately easy to add a portal mechanism...we discussed that
a couple of days ago.

No BSP trees - the thing that PLIB implements is better (unless you are trying to
render without a Z buffer - in which case I don't think you should be using PLIB
at all).

Octrees are really just a way of using what PLIB already does.

> If I were to implement an octree using plib, would it typically be a single
> ssgNode object or rather a separate node for each octree volume with some
> sort of a custom intelligent (much more complex than the class I think is
> called ssgSelector) branch class that would look after these issues?

You could either have a single ssgBranch node - with (up to) eight other
ssgNode's beneath it - and allow SSG to do FOV culling...or you could derive
a class from ssgBranch that would do fancier culling given that it has more
information about the structure of the model than ssgBranch does.
 
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