Re: [Plib-users] ssgEntity::getBSphere() strange results

[Steve B. <sjb...@ai...>]

"McEvoy, Nick" wrote:
> 
> I have drawn a sphere in AC3D (a 3D modelling tool) of radius 10 and centred
> at 0,0,0 ... I load the sphere model (ssgLoadAC3D) and check its bounding
> sphere ... getBSphere().
> 
> Why does the bounding sphere radius return 17.9544 ???  And the centre is
> -1.27190,-0.726630,0.303701 ???

Well, I'm a little puzzled - but one thing I've noticed is that AC3D is
rather 'fuzzy' about when it creates a transform node in it's internal
scene graph and when it actually transforms the vertices in place.

Hence, it's possible that you did something like create the sphere with
it's center at -1.27,-0.72,0.30 - and then dragged it so that it was
centered over 0,0,0.  If that's what happened, then the *vertices* of the
sphere would contain numbers that placed the center at -1.27,-0.72,0.3 - but
then the SSG loader would generate an ssgTransform above the sphere to
move it back to the origin.  Hence, the bounding sphere's center could be
where you see it.

That's a guess though.

----------------------------- Steve Baker -------------------------------
Mail : <sjb...@ai...>   WorkMail: <sj...@li...>
URLs : http://www.sjbaker.org
       http://plib.sf.net http://tuxaqfh.sf.net http://tuxkart.sf.net
       http://prettypoly.sf.net http://freeglut.sf.net
       http://toobular.sf.net   http://lodestone.sf.net