On 25 Apr 2012, at 14:22, Stuart Buchanan wrote:

> Perhaps I should be using a QUAD_STRIP instead. Don't know if that
> would make much difference though.

Doubtful, I'd say, if they are already in a single primitive set.

> 
> The extra 300 Drawables are from the quadtree that is generated to a)
> make culling fast b) to provide a mixture of LOD so that buildings
> don't all appear in big blocks.  That code is taken directly from the
> random vegetation,  and I could look at reducing the size of the quad
> tree, at the expense of worse cull performance and/or less fade-in.
> 
> (I must own up to not looking at the OSG stats before now

Okay, this seems way too many drawables to me. Recalling Robert's target of 
about 4000 drawables maximum per scene, which we regularly blow out of the 
water.... What's the gain of so many drawables vs one LOD node per tile?

I'm firmly in the 'small, compact scene graph with massive leaves' camp, you 
see. If part of the tile is visible, great, submit the whole damn lot and I'm 
confident the card will cope :) You could quad tree down a couple of levels if 
you insist, but I'd be thinking no more than a 2 or 3. (And the same for random 
vegetation)

In fact, could you make the quadtree depth a config option? With 0 as a 
permissible value?

> The relevant code for the random buildings is in
> scene/tgdb/SGBuildingBin.cxx (IIRC), and would be pretty easy to hack
> into not very pretty triangles by simply commenting out the fourth
> vertice in each block, if you didn't mind living in an abstract house
> :)

Will give it a go.

Cheers,
James


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