[ODE] Regarding CSG

[gl]

The subtractive CSG thing ocurrs to most ODE users sooner or later (it did 
to me once : ), but there's one fatal flaw: subtraction creates all kinds of 
funky shaped edges - and these edges need to be collided against.  So 
disregarding contacts inside a 'negative' geom is not enough.

I doubt it can be done without triangulating.
--
gl

----- Original Message ----- 
From: "Peter" <twentyseven at urbanterror.net>
To: <ode at q12.org>
Sent: Tuesday, October 05, 2004 3:38 AM
Subject: [ODE] Regarding CSG


> For whoever asked this a couple of days ago, CSG is Constructive Solid
> Geometry.  Theres really two operations in CSG, addition and subtraction,
> adding objects together to create volume, or subtracting one object from
> another to remove volume.  Addition is supported natively in ODE via
> clumping multiple geoms together via the use of GeomTransforms, so you 
> could
> make the ODE docs example of a table with 4 legs by creating 5
> geomTransforms, 5 boxes, and positioning them all on one body.
>
> As far as CSG subtraction goes, well, it's not supported natively, but you
> could probably create "negative" geoms that remove contacts that fall 
> within
> them, so say you wanted to use a sphere to cut a hole in a box - if the
> contact falls within the sphere, cancel the contact.  No idea if it'd work
> and you're probably better off with using meshes and doing mesh based csg
> externally of ode.
>
> Just wanted to chime in with the geom stuff though.
>
>
>
>
> _______________________________________________
> ODE mailing list
> ODE at q12.org
> http://q12.org/mailman/listinfo/ode
>