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BwB
03-17-2001, 11:48 PM
Again this is directed primarily at Matt http://www.opengl.org/discussion_boards/ubb/smile.gif

Does keeping all textures the same format provide any benefits? I've discussed this with my artist and he has no problem sticking solely to one format (either 16 or 32) but does it hurt to mix the two? And how big is the cost of using 32bit textures over 16bit textures? Obviously 32bit textures take more bandwidth, but if we go with 16bit textures we'll use twice as many! Hmm... I think I'll start compiling all this information in a faq http://www.opengl.org/discussion_boards/ubb/wink.gif

I cant express enough how much I love you guys!!! You help me SOOOO much!! Thank you!!

mcraighead
03-18-2001, 03:41 PM
16-bit textures help exactly as much as you would expect -- they take half the memory, they take half as long to download, and they require half as much memory bandwidth.

- Matt

zed
03-18-2001, 11:40 PM
>>ive same format provide any benefits? I've discussed this with my artist and he has no problem sticking solely to one format.<<

what graphic file format supports 16bit textures??

Bob
03-19-2001, 02:31 AM
The question is not what fileformat uses 16-bit texture, the question is what parameters you use when uploading the texture. You can load a 32-bit texture as usual, but select the internal format GL_RGBA4 when uploading the texture with glTexImage2D for example. That will upload the texture as 16-bit RGBA.

Humus
03-19-2001, 05:58 AM
Originally posted by zed:
>>ive same format provide any benefits? I've discussed this with my artist and he has no problem sticking solely to one format.<<

what graphic file format supports 16bit textures??

TGA for instance.

kieranatwork
03-22-2001, 09:15 AM
tga's and bitmaps...
...pretty obscure file formats, I know, but useful nonetheless http://www.opengl.org/discussion_boards/ubb/smile.gif

zed
03-22-2001, 11:28 AM
are u sure they support 16 bit textures eg data in R4G4B4A4 or R5G5B5 etc.
i havent checked but i thought they were limited to 8,24,32 + maybe 64 bit.

BwB
03-22-2001, 12:48 PM
I just checked and photoshop allows saving targas in a 16bit format. I'm not sure, internally exactly how the alpha is done.

Humus
03-22-2001, 01:10 PM
I think it's R5G6B5.

ikk_flip
03-22-2001, 10:21 PM
the loading time for decreasing the texture color bit data from 32 bit to 16 bit may a thing to consider if you are loading many, many textures at once. Someone mentioned 64bit textures, heheh... 64bit color would take a whole freaking lot of computation. Plus the eye can't see more colors that 32bit. But maybe doing things in 64bit would provide more accuracy.
Another thing about having the alpha channel in 16bit files. There is none, but it tries to use colors that are close to the original ones in the alpha channel. So pictures with a lot of alpha and normal color would appear worse quality in 32 bit.

Serge K
03-23-2001, 07:57 PM
Originally posted by Humus:
I think it's R5G6B5.
16bit TGA - 5:5:5