[sldev] Why does the simulator do object culling for clients?

[John Hurliman]

Argent Stonecutter wrote:
>
> Unless there's going to be some kind of genuine privacy scheme 
> implemented in SL (which is another topic near and dear to my heart, 
> but not one I'm going to go into now), I don't think there's much that 
> the client can't see in the sim it's in. The longest diagonal in the 
> building zone of a sim is 849 meters, which means that an agent at 
> <128,128,384> with a draw distance of 512 can see any object in the 
> sim. Worst case, you can see well over 50% of the volume of the sim 
> from any point in the sim, and from a corner you can see well over 50% 
> of the volume of four sims at once.
>
> I think the only consideration given to the "privacy" issues of this 
> scheme are that a sim should kill objects for clients in sims more 
> than two sims away. That's a *cheap* calculation, and more an 
> optimization than anything else.

You can actually have sim-culled privacy if you have a large enough plot 
with ban lines and build everything very very small. The simulator won't 
send *everything* in your draw distance, it culls small enough objects 
that are far away enough from your avatar, putting a damper on 
implementing good pathfinding code in libsecondlife.