Problem displaying objects that are sub-pixel size

New Message Reply Date view Thread view Subject view Author view

Charles Seberino (seberino++at++or_lab.tu.hac.com)
Tue, 3 Feb 1998 10:39:02 -0700

I am having a problem displaying small polygons, which when viewed at long
distances, don't (or rarely) appear on the screen. Here is what I am trying to
do:

Creating several hundred OPENGL GL_QUADS with the same texture applied to each
of them. The polygons are drawn so that they are always facing the
display(billboarded). The problem I get is when I view the polygons(1 in^2
each) from far away, the individual polygons only take up from 1-4% of a screen
pixel. The polygons are all close to each other so I should be seeing the
cumulative effects of all the objects(a particle cloud), but I only get a pixel
every so often. I am using a luminance-alpha texture to display the square as
a sphere. I have tried changing the minification filters, but none give the
correct result.

What can I do to get these objects to appear as they should?

I decided not to go the route of creating several hundred pfGeoSets/pfGeodes
(maybe pfBillboards) because I thought it would be more time consuming and not
give any added benefit.

Running on Onyx2 IR pf2.1

Any suggestions?

Charles

-- 
-----------------------------------------------------------------------
Charles Seberino                    Raytheon Missile Systems Company
seberino++at++or_lab.tu.hac.com          phone: (520) 794-7078
                                    fax:   (520) 794-8625
=======================================================================
List Archives, FAQ, FTP:  http://www.sgi.com/Technology/Performer/
            Submissions:  info-performer++at++sgi.com
        Admin. requests:  info-performer-request++at++sgi.com

New Message Reply Date view Thread view Subject view Author view

This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:56:43 PDT

This message has been cleansed for anti-spam protection. Replace '++at++' in any mail addresses with the '@' symbol.