DOOM3, 3Dc, DXT5 and more

[Richard]

I mailed Robert Duffy (id Software programmer) asking three questions. One of which was if DOOM would support 3Dc. Here's what he replied:

We do not support 3Dc but for medium quality mode we do swizzle the red and alpha components and use DXT5 compression. In high quality mode we use uncompressed normal maps. In most cases the swizzled compressed versions do a really good job apart from hard angles or curved edges. It was a good trade off for lower memory video cards. ATI has a good write up on various methods of normal map compression on their site.

You can also check the other two replies here:

http://www.forumplanet.com/planetdoom/topic.asp?fid=5733&tid=1413239

 

[AlNom]

how much vid card memory would be good then?


(for uncompressed normal maps)

 

[DSN2K]

Dont think ID will be making any effort to support new stuff like 3Dc, SM3.0 etc. (at least until its shipped)

I think getting things right on existing hardware in gamers hands is more important.

 

[991060]

Then the quality of Cg compiler affects the performance? Hmm, I can smell another flame war coming soon.

 

[LeStoffer]

Then the quality of Cg compiler affects the performance? Hmm, I can smell another flame war coming soon.

Huh?

We don't do anything in DOOM 3 using Cg but we have support for it ( though I am not sure how much it has been tested lately and that is not a guarantee it will work).

Sounds like old code not in play anymore to me.

 

[Cryect]

Well cg support will be nice for mod makers considering how easy it is to work with cg at least. Heh, how many mod makers do you think will be working real hard at having their shaders be optimized to the max. Actually what will likely happen of course is a few guys will make a bunch of shaders that everyone else ends up using in addition to the ones that come with the game (though its going to be interesting to see how mod makers respond to everything with mods will be open source in Doom 3).