[sldev] High-prim vehicles using phantom (Re: Havok4...)

Dale Mahalko dmahalko at gmail.com
Sun Sep 30 18:41:36 PDT 2007


On 9/30/07, Candide LeMay <candide.lemay at gmail.com> wrote:
> What are you guys talking about? Currently you can't have a linkset
> that has some of its prims phantom and others not phantom. Am I
> missing something?


This is a new design concept, that is an extension of prim data that
apparantly isn't currently being used for anything.

When part of a linkset, most likely each individual prim in the
linkset still retains its database storage space for the "phantom"
checkbox when separate prims are linked into a set.

As designed now, the individual phantom checkbox values are all
apparantly being ignored or reset to unchecked, in favor of the one
single linkset setting for phantom or not, which applies to everything
in the linkset.

Linksets could likely contain individual phantom and non-phantom
primitives, by utilizing these data bits that are apparantly currently
going unused.

When such a linkset is set to be physical, we already know that
phantom objects can't be physical so those objects within the set can
simply be ignored for the mass / collision / center-of-gravity
calculations.

Supporting this should not require any changes to how prim data or
linksets are being stored on the server, and so doesn't require a new
prim type or data storage method. It's mainly just a change in that
the act of linking multiple objects together will not remove the
individual phantom settings for objects linked into the set.

Then an engine change is needed to look for this new phantom bit that
individual prims in the set may carry, and to individually disregard
each prim in the linkset that is set to phantom. And also, precheck
any linkset attempting to be set physical to make sure it contains no
more than 31 non-phantom primitives.


This would provide the additional prim capacity people have been
repeatedly requesting in order to improve vehicle detail, while at the
same time allowing LL to stay at 31 physical prims per vehicle and not
increase the engine load to support higher vehicle prim counts. It's
efficient all the way around, and apparantly could work on both
Havok-4 and Havok-1..

- Scalar Tardis / Dale Mahalko


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