Chris Henderson (ch++at++paradigmsim.com)
Thu, 07 Jan 1999 08:23:02 -0600
I've used this function to implement a 'preCull' algorithm to generate
pfDisplayLists containing all the geometry that is visible in a given
viewing condition. It works well.
ch.
Simon Gerblich wrote:
> Hi,
>
> Take a look at glFeedbackBuffer. You can use it to get back a list of
> all of the polygons in the visible scene. You can then go through each
> polygons vertex list and see its x, and y value and its depth and color
> value.
>
> Simon
>
> > Hi,
> > I want to know whether there is an easy way
> > (or a way at all) to find which all triangles are visible
> > (at least partialy) in a scene, given a model, viewpoint and direction.
> > There are of course methods to intersect line segments of different
> > lengths for each pixel, check the closest point, find the corresponding
> > triangle etc. That seems to take too long to compute for each view.
> > I want to know if there are any faster ways taking advantage of
> > some Performer feature or other ...
> >
> > Thanks in advance!
> >
> > Anoop.
> >
> > =======================================================================
> > List Archives, FAQ, FTP: http://www.sgi.com/software/performer/
> > Submissions: info-performer++at++sgi.com
> > Admin. requests: info-performer-request++at++sgi.com
>
> --
> ================================================
> Simon Gerblich
> Acacia Research Phone (08) 8272 9455
> 153 Greenhill Road Fax (08) 8272 6899
> Parkside SA 5063 Int. +61 8 8272 xxxx
> mailto:simong++at++acres.com.au
> ================================================
> =======================================================================
> List Archives, FAQ, FTP: http://www.sgi.com/software/performer/
> Submissions: info-performer++at++sgi.com
> Admin. requests: info-performer-request++at++sgi.com
-- ------------------------------------------ Chris Henderson ~ Multigen-Paradigm Inc (972) 960-2301 FAX (972) 960-2303 mailto:ch++at++paradigmsim.com http://www.paradigmsim.com
You can test the bounding sphere of a particular subtree for inclusion in a supplied channel with the function pfChanContainsSphere().
I've used this function to implement a 'preCull' algorithm to generate pfDisplayLists containing all the geometry that is visible in a given viewing condition. It works well.
ch.
Simon Gerblich wrote:
Hi,Take a look at glFeedbackBuffer. You can use it to get back a list of
all of the polygons in the visible scene. You can then go through each
polygons vertex list and see its x, and y value and its depth and color
value.Simon
> Hi,
> I want to know whether there is an easy way
> (or a way at all) to find which all triangles are visible
> (at least partialy) in a scene, given a model, viewpoint and direction.
> There are of course methods to intersect line segments of different
> lengths for each pixel, check the closest point, find the corresponding
> triangle etc. That seems to take too long to compute for each view.
> I want to know if there are any faster ways taking advantage of
> some Performer feature or other ...
>
> Thanks in advance!
>
> Anoop.
>
> =======================================================================
> List Archives, FAQ, FTP: http://www.sgi.com/software/performer/
> Submissions: info-performer++at++sgi.com
> Admin. requests: info-performer-request++at++sgi.com--
================================================
Simon Gerblich
Acacia Research Phone (08) 8272 9455
153 Greenhill Road Fax (08) 8272 6899
Parkside SA 5063 Int. +61 8 8272 xxxx
mailto:simong++at++acres.com.au
================================================
=======================================================================
List Archives, FAQ, FTP: http://www.sgi.com/software/performer/
Submissions: info-performer++at++sgi.com
Admin. requests: info-performer-request++at++sgi.com-- ------------------------------------------ Chris Henderson ~ Multigen-Paradigm Inc (972) 960-2301 FAX (972) 960-2303 mailto:ch++at++paradigmsim.com http://www.paradigmsim.com
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