[ODE] SAP space (was: Large physics worlds...)

[Eric Froemling]

Sweet! Thanks much.  I applied it to my local build and speeds were 
improved over simple and hash spaces for my initial tests.
Anyone want to submit this to unstable or whatnot?

Eric

On Apr 25, 2005, at 1:57 AM, Aras Pranckevicius wrote:

>>> Should I package the patch again, and maybe submit/upload it 
>>> somewhere?
>>>
>> I know I for one would love to try it out...  Are there any major
>> issues with it?
>
> Ok, here goes the sweep-and-prune space for ODE:
> http://nesnausk.org/nearaz/files/ode-sapspace-050425.zip (30kb).
>
> It's not a patch, as I don't have diff/patch right now and am too lazy
> to get them. Some readme is included; basically it's one new cpp file
> and a couple of lines added to ODE include files. Should be pretty
> basic to integrate.
>
> Now, about it:
>
> * Does complete re-sort on each collide call. That is, no temporal
> coherence of any kind. The good side of this is that it handles very
> fast moving things well.
>
> * Has no collide2 implemented :(
>
> * Depends on Opcode sources being present (collision_sapspace.cpp
> includes Opcode.h and uses radix sorter from there).
>
> * Uses radix sort for the sweep phase. Uses single precision floats
> internally (ODE can still use doubles), which I think must be standard
> IEEE floats (Opcode's radix sorter assumes IEEE floats). I think
> that's not a problem on most platforms.
>
>
> In my own usage scenarios, I've seen SAP either beating other spaces
> by large amount, or beating them by small amount :) YMMV.
>
>
> -- 
> Aras 'NeARAZ' Pranckevicius
> http://nesnausk.org/nearaz | http://nearaz.blogspot.com
>
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