@Mustang

Hi,

i wanted to ask what's the best you've (futurecrew) experienced with delivering textures. I guess there are cases where it's better to use a) instead of b) but i would like to know how you think about this.

So are you using straight DXTC? If so any exceptions where you don't us it? Do you limit the usage to the diffuse part and keep normal maps for example away from these? Or are you more using JPGs which you afterwards use as DXTC or as RGB(A) in memory? Did you ever use ATI's 3DC?

...


Regards,

taumel

email->http://www.blitzbasic.com/Account/showuser.php?id=2636

Umm... some ramdom ramblings:

We keep our textures in .TGA format through editing / development phase - JPG's don't work at all because they decompile / compile everytime you load and edit the texture... soon there would be only messy piece of artifacts left. So while editing everything is uncompressed and lossless.

When we start the app it converts the textures automatically to any format artist wants, usual formats being DXTC [1, 3, 5], uncompressed A8R8B8G8, HDR and cubemaps... plus few strage ones for special purposes.

You cannot compress normal maps because compressing alters the image -> screws the normals in the map [clever, eh?]. We do some special tricks to pack normal maps so that they are smaller but not lossy.

Also some textures are better left unpacked like fine color/mask gradients because they show "banding" very easily if you do that... SkySpheres/boxes are like this usually.

Specular, ambient occlusion and lightmaps (we hardly ever use lightmaps anymore) are usually DXTC packed too.

Final install package has usually DXTCs although these create bigger package. Like I said JPG's are handy for "bikini girl images" but texture artists usually think they are evil and bad. Unless you ABSOLUTELY have to create small install package... and there's also question about JPG licences so like .MP3 it's just best to avoid it like plague.

ENAY, it should be safe to post even email addresses here... although I appreciate that you did not. :)

@Mustang

For online distribution i've used jpgs quite often in the areas where they are useful. I just did a few quick tests and saw that depending on the situation you can run quite easily into banding with dxtc and beside of that they are already in a proper gfx-format and so faster to use for the gfx-card they are sometimes bigger and provide less quality than going with jpgs without compression afterwards. Of course i was asking only after the final stage.

Certainly all depends on what you're after (filesize, speed, quality) but i was just thinking what your thoughts are about this so thanks for answering.

By the way why do you prefer TGA instead of TIFF or other losless formats?

And i guess you won't talk about your normal map compression?! ;O)

I think that it was just easiest for our coders to write a .TGA loader module to our engine years ago, so that decided the format and it has stuck. No reason really why it couldn't be .tif or something else with alpha capability (.tif has alpha channel too, right?)



No. :)

...But these should give you some clues:

http://download.nvidia.com/developer/Papers/2004/Bump_Map_Compression/Bump_Map_Compression.pdf

http://www.ati.com/developer/NormalMapCompression.pdf

Regarding TIFF:

Yep. The nice thing about tiff is that it also keeps your photoshop layers intact. Dunno about TGA...

Regarding Compression:

Okay thanks! :O)