From: Tomlinson, Gordon (GORDON.TOMLINSON++at++ca.com)
Date: 02/15/2001 08:10:46
HI
If your read the man page it does tell you why you
need pfHit **[], basically you need an entry in the
array for each segment you have.
Gordon.
_________________________________________________________________
Gordon Tomlinson
Manager Urban Simulation Products.
MultiGen-Paradigm Inc
"a Computer Associates Company"
Suite 400, 14900 Landmark Blvd Dallas Texas 75240 USA
Tel: 972 960 2301 ext 309 Fax: 972 960 9049
Email: gordon.tomlinson++at++cai.com <mailto:gordon.tomlinson++at++cai.com>
______________________________________________________________
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NOTE:
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-----Original Message-----
From: Boris Mansencal [mailto:boris.mansencal++at++inria.fr]
Sent: Thursday, February 15, 2001 2:18 AM
To: Angus Dorbie
Cc: info-performer++at++sgi.com
Subject: Re: Intersection testing
Angus Dorbie wrote:
>
> Looks like I was wrong the hit array is for multiple segments (as you
> suggest).
>
> Looks like you'd need to use callback to get access to all the segments.
I don't really understand your answer. Why would I need to use callback
?
With the current behavior, I can access to the 'closest' intersection of
each segment with the scene. But what I need is all the intersections
of
a given segment with the scene.
I thought that it was possible because we pass a pfHit **[] to isect,
but
it seems it is not.
So I don't understand why we do not pass only a pfHit *[] ?
Is it for a coming feature ?
Is the behavior that I expected present in the 2.4 release ?
If not, do you think to a clever way to do this ?
Thanks a lot,
Boris.
>
> Cheers,ANgus.
>
> Boris Mansencal wrote:
> >
> > Angus Dorbie wrote:
> > >
> > > Boris Mansencal wrote:
> > > >
> > > > Hi,
> > > >
> > > > I would like to get all the geometries intersected by a segment.
> > > > It is not possible with pfNode::isect(pfSegSet *segSet, pfHit **hits[],
> > > > isn't it ?
> > > >
> > >
> > > It is possible.
> > >
> > > > So, why do we need to give a pfHit **[] and not only a pfHit *[] if we
> > > > get only
> > > > one intersection point by segment ?
> > >
> > > Because it's possible :-)
> > >
> >
> > So, as isect returns n the number of intersections, I will have n pfHit*
> > from hits[0], right ?
> > Is it still working with several segments ? How do I know the number of
> > intersections for a given segment ?
--
Boris Mansencal
INRIA Rocquencourt (France) - projet i3D
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