Does Ogre, support 'indexed' tga files?

2019 · Post by **2019** » Fri Apr 22, 2005 12:59 pm

It's somehow more efficient, especially when you don't notice the diffrence in colours and don't need the alpha.

I think it should be no problem, but i just want to know it for sure.

(i know that i could load it up to ogre, but in mesh viewer i never been able to see my materials, and in the material editor, the software always crash.)

cheers,
p

Post by **:wumpus:** » Fri Apr 22, 2005 1:10 pm

It supports them if DevIL can load them.

2019 · Post by **2019** » Fri Apr 22, 2005 1:14 pm

DevIL? huh?
is that build in ogre?

sorry my knowledge is zero when come to non content.

Post by **:wumpus:** » Fri Apr 22, 2005 1:16 pm

It's the image library that OGRE uses. If indexed tga won't work, use indexed png, or gif even.. It can be a problem with older versions of ogre though; make sure you use 1.0.1 or 1.0.0

2019 · Post by **2019** » Fri Apr 22, 2005 1:22 pm

Thanks Wumpus

McSwan · Post by **McSwan** » Sat Apr 23, 2005 2:48 am

I'm fairly sure the image format of choice is dds. It takes up less video memory, and is designed for use in games.

2019 · Post by **2019** » Sat Apr 23, 2005 5:25 am

YEs dds is good for games, but i've read that it's limited to the highest map of 256-256 pixels.
We're doing a more game for the future comps, well yea the actual realese is in about couple years, so well look good in to the future and go for 1024-1024 and some 2048-2048 maps.
tgas can get you there, but the size would be rather high, so indexing is a perfect solution, since you won't see the diffrence between a 24bit map.

I wonder why not more games use that indexing in their tga files, it reduces size to 25% and is still good.

Post by **:wumpus:** » Sat Apr 23, 2005 2:20 pm

The man is right!

DDS can do DXT1 (up to 16x saving without alpha!), DXT3/5 (8x saving, with alpha). Because the effect of DXT is local instead of global it is generally deemed better quality than indexed. Also, because cards generally do support compressed textures natively (in the future, even better compression formats might appear), but not indexed textures, this saves a lot of texture memory and bandwidth.

There is also *no* limit on DDS sizes. I don't know how you came up with that.

2019 · Post by **2019** » Sat Apr 23, 2005 2:55 pm

I've read once on a site about it's limitations.\i dunno exatly where.
Well thanks for the information, i'll do some tries with dds.

Post by **sinbad** » Sat Apr 23, 2005 5:57 pm

It would be pretty stupid if DDS was limited to 256x256, since one of the main reasons for texture compression is to use large textures in reasonable texture memory! Be careful what you read...there are a lot of people out there who don't know wtf they're talking about, especially on 'l33t' gaming sites

Deamon · Post by **Deamon** » Sun Apr 24, 2005 5:22 am

:wumpus: wrote:Because the effect of DXT is local instead of global

What does that mean ?

Deamon

Deamon · Post by **Deamon** » Sun Apr 24, 2005 5:25 am

sinbad wrote:Be careful what you read...there are a lot of people out there who don't know wtf they're talking about, especially on 'l33t' gaming sites

BTW: What do 'l33t' stands for ?

Deamon

qsilver · Post by **qsilver** » Sun Apr 24, 2005 9:21 am

"l33t" is what 13-year old AOL chat kids write when they mean "elite" but are too cool to type properly

I can refer you to this excellent reference site: http://www.bbc.co.uk/dna/h2g2/A787917

As for the "DXT is local" comment, :wumpus: was referring to DirectX texture compression. The Direct X compression formats all compress local blocks of pixels, without looking at the rest of the texture.

This means that no matter how much detail or how many colors are in one area of the texture, it will never affect the quality of another area. That's quite a contrast to palette indexed images, where you have a limited number of colors to work with; if one area of the image uses a lot of colors, the rest of the image will suffer because it has less available colors to work with.

Chris Jones · Post by **Chris Jones** » Wed May 04, 2005 11:44 pm

agh, i hate people with all that "l337" rubbish, theyre also people that think hacking is breaking into systems

anyway

about using DDS, blender, i dont think, supports dds, and u have to loads bmp or tga etc, can i get it to use a dds file easily, either blender or the model after export, or do i have to do alot to get it to? btw im not a graphics artist/modeller, this is for a mate that will be doing the graphics for our game

Post by **:wumpus:** » Wed May 04, 2005 11:48 pm

It's not a convient format to use in the modeller or graphics package (lossy compressoin), you should convert the textures from whatever format your texturer uses to DDS just before they go into your game.

Chris Jones · Post by **Chris Jones** » Thu May 05, 2005 5:16 pm

i want to use DDS, just that blender doesnt allow you to use it, when the model is exported, how can i change what texture the model uses? the DDS version instead of tga or bmp etc

McSwan · Post by **McSwan** » Thu May 05, 2005 11:27 pm

Just open the .material file and chang the file name

Vectrex · Post by **Vectrex** » Fri May 06, 2005 5:15 am

doesn't dds only work on a certain generation of gfx card? What about those lame integrated intel 'gfx cards'? What happens when you try a game that uses dds on a non-dds capable card?

Post by **:wumpus:** » Fri May 06, 2005 9:22 am

If your card has no capapbility for compressed textures (very rare these days) Ogre will decompress it for you on load

joshcryer · Post by **joshcryer** » Fri May 06, 2005 3:11 pm

:wumpus: wrote:If your card has no capapbility for compressed textures (very rare these days) Ogre will decompress it for you on load

Cool, I didn't know that. Ogre continues to impress.

Vectrex · Post by **Vectrex** » Fri May 06, 2005 9:20 pm

yeah that rocks. In that case i guess there's no reason at all not to use dds?

2019 · Post by **2019** » Thu May 19, 2005 12:00 pm

The fine thing of .dds is are its mip maps.

But how can it knows at which point it should degrade it self?

McSwan · Post by **McSwan** » Sun May 22, 2005 10:54 pm

I heard a rumour dds don't work when you put a normal map in them. Is this true?