[sldev] Optimus Prim vs. Megatrim: "The Big Prim Problem"

Andre Roche roamingryozu at gmail.com
Wed Oct 17 10:44:00 PDT 2007


On 10/17/07, Kelly Linden <kelly at lindenlab.com> wrote:
>
>  Callum Lerwick wrote:
>  On Wed, 2007-10-17 at 11:06 -0500, Argent Stonecutter wrote:
>
>
>  On 17-Oct-2007, at 09:15, Dzonatas wrote:
>
>
>  What to do with the megaprims?
>
>  Keep them, let people create and rez new megaprims up to 256 meters,
> don't make it a complex operation to do so, don't magically convert
> prims into linksets, just ignore them in the physics engine.
>
>  Well, you can't completely ignore them in the physics engine.
> Disallowing them from being set physical would be reasonable. Forcing
> them phantom would dramatically reduce their utility. I use them to make
> floors. Why use up 9+ precious prims for a floor when I can just use a
> single megaprim? :)
>
> Using invisiprims for collisions would defeat the whole point of using
> megaprims for prim-scrimping...
>
> You need to perform collision detection on megaprims. The fact that the
> megaprim itself is not physical however should prevent the need to merge
> "simulation islands" in the physics engine, which was previously cited
> as a major performance concern.
>
>
>  This last bit is not true.  Large prims, even if they are "static", still
> effect the simulation islands.
>
>   - Kelly
>
>

It's true that even "static" and "phantom" objects are handled by the
physics engine, hence collision detection via llVolumeDetected and
physical phantom prims, etc.

But that does beg the question:  If a megaprim is not dynamic, does it
really need to collapse simulation islands it touches?  Would it be
possible to simply prevent that?


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