[sldev] Re: [ARCH] Render unto Caesar the things that are Caesar's

Argent Stonecutter secret.argent at gmail.com
Mon Sep 24 12:39:23 PDT 2007


On 24-Sep-2007, at 13:54, Mike Monkowski wrote:
> I guess the important thing is to not expect the sim to be a  
> monolith. Allow partitioning of the tasks so that if someone is  
> willing to throw the hardware at it, they could do, e.g., collision  
> detection on custom avatar meshes.  As you pointed out, this has an  
> effect on the communications load, so it's not just a black box  
> partitioned any way you like.

Not just the communications load. You'd have to change the protocol  
to get the client to track the behavior of the sim and vice versa. If  
you're going to do that, it might be more efficient for the client to  
handle that level of collision detection (not full on physics, just  
looking for intersections), and inform the sim when they occur.

You probably wouldn't be using this detailed a level of physics for  
gross physical movements. Games typically have two collision  
envelopes for characters... a coarse one like the SL bounding box to  
control when the character is blocked, and a fine one to allow the  
character to effect objects. Neither of them is detailed down to the  
mesh level, the fine one is usually based on a stick figure made of  
convex surfaces around each bone.

So walking along, the client would detect that your left foot has hit  
a box on the ground, and it'll let the sim know that it's occurred  
and what the impulse vector should be. If the client's updates aren't  
recent, then the sim would fall back on the coarse bounding box for  
both purposes.


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