Geb Thomas (gthomas++at++w-ie24.icaen.uiowa.edu)
Mon, 17 Feb 1997 12:56:26 -0600
I'm writting an application in which I hope to change 4 512x512 color textures
as often as six times a second. The trouble is that the new images will arrive
as the application is running, so they can not be pre-loaded as a movie.
Can you help me find the best approach?
Right now I load the first set of images with the geometry in an Inventor file.
This seems to make them mipmapped, so I reformat each one with the following
commands:
tex->setFormat(PFTEX_FAST_DEFINE, PF_ON);
tex->setFormat(PFTEX_GEN_MIPMAP_FORMAT, 0);
tex->setFilter(PFTEX_MINFILTER, PFTEX_POINT);
tex->format();
They have an Internal Format TX_RGB_5 (full speed), an External Format
TX_PACK_8 and a subload format. The load modes are:
PFTEX_LOAD_SOURCE = 0
PFTEX_LOAD_BASE = 0
PFTEX_LOAD_LIST = 0
Each image buffer is 524288 bytes large.
I don't have the external image source connected to the machine
(eventually it will be a network connection). Instead, on every fourth frame
I manipulate each image pixel by pixel and call tex->load(). The stats say
the O2 is going 9.5 loads on average or 5308416 bytes.
I understand that the Reality Engine will subload the textures much faster.
Can I expect to load 3 Mbytes per second and still have an interactive
application? Are there other options I could pursue for my O2 or Onyx
machines? Are there games I might play with the video framebuffer?
Many thanks in advance for taking the time to consider my troubles.
Geb Thomas
The GROK Lab
The University of Iowa
gthomas++at++icaen.uiowa.edu
_____________________________________________________________________
Geb Thomas, PhD
Assistant Professor of Industrial Engineering, The University of Iowa
Phone: (319) 335-5936 Fax: (319) 335-5424
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