Angus Dorbie (dorbie++at++sgi.com)
Fri, 17 Jul 1998 09:46:13 -0700
This probably doesn't save as much texture memory as you think.
When CLIP texturing, even the levels of MIP smaller than the CLIP size
take up a CLIP sized area of texture memory. This means that your 2K by
2K image has 11 levels each 512 by 512 = 2.88 Mtexels one 2048x2048 MIP
mapped texture uses 5.5 Mtexels. So CLIP textures really help most when
you have larger image data sets, something this small is only about a
2:1
saving unless you reduce the CLIP region size. Your 11 CLIP textures
will
use at least 2 bytes per texel, so texture memory useage will be
11 textures * 2.8836 mega texels per texture * 2 bytes per texel = 63.4
MB
of texture memory useage. So, it's likely that you are running out of
texture
memory when you try to add your eleventh CLIP texture. The numbers don't
quite
add up to greater than 64 MB but it's not far off. Do you have other
textures
in the scene?
Cheers,Angus.
-- "Only the mediocre are always at their best." -- Jean GiraudouxFor advanced 3D graphics Performer + OpenGL based examples and tutors: http://www.dorbie.com/ ======================================================================= List Archives, FAQ, FTP: http://www.sgi.com/Technology/Performer/ Submissions: info-performer++at++sgi.com Admin. requests: info-performer-request++at++sgi.com
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