Many Textures/Slow Draw
Dwight Meglan (dwight++at++ht.com)
Sun, 18 Feb 1996 20:55:43 -0400
Have a small problem and I am not too sure what it is. We have an app which
loads
52 textures (totalling about 3.4 Mb) on a High Impact (with 4Mb of TRAMS). The
scenegraph was built in Designer's Workbench, and the app is built around
perfly.
The problem is this:
The draw phase has become very slow (70-100 msec) and we are down about
12 fps. Looking at the gfx stats, it *appears* that all 52 textures are being
continually reloaded (the loads line goes from 0 to ~1300 by 52's and the Mbytes
line increments accordingly).
Load statistics say that we are using about 85% of our 4Mb texture mem.
Then, if I go through the scenegraph and delete some of the textures,
performance
improves slightly. Finally, when I have deleted textures down to about 1.8Mbyte
(less that 50%) performance improves radically, and the multiple loads behavior
disappears.
So, what is going on, and how can we fix it? Is the behavior a function of
having
many different texture sizes? Since we have enough texture memory to load the
textures once and save them, why is it (apparently) reloading them
constantly? Only
some of the textures are not powers of two, but all of the numbers that I
have given
here are after the automatic texture expansion behavior. Oh, several of the
textures
are reused a number of times, but they are all small (either 32x32 or 128x128).
Any help would be appreciated.
Thanks,
Dwight
dwight++at++ht.com
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dwight Meglan, PhD | Developers of complete surgery simulation
Engineering Coordinator | training systems and surgery simulation
High Techsplanations, Inc. | creation software tools
6001 Montrose Rd., Suite 902 |
Rockville, MD 20852-4874 | "Witty, yet erudite saying goes here..."
301 984 3706 x38 |
301 984 2104 : FAX |
dwight++at++ht.com | http://www.ht.com
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