Quake engine differences?

[frag.machine]

Quake 3 uses md3 not skeletal skeletal first made its apperance in id tech 4 (doom 3 etc.)

first engine to implement megatexture was enemy territory quake wars, the code was allready in doom3 but not used and in a very early stage.

model formats by engine.

Quake 1: mdl.
Quake 2: md2
Quake 3: md3
Doom 3/Quake 4: md5 (some say skeletal tbh im not sure).

as far as i know no game by ID ever used the md4 format but i remember a thirdparty game using it (title illudes me atm).

RTCW ?

[goldenboy]

megatexture only needs to keep the same image in memory resulting in some substantial speed gains and less stress on hardware.

If that is true, it's even more amazing that ETQW runs noticeably slower than both Doom 3 and Quake 4.

[revelator]

RTCW used md4 ? hmm ok didnt know that.

if i read it right enemy territory only uses megatexture for 2D passes not for the entire thing so still a lot of texture operations going on.

there does seem to be quite a bit of different explanations out there though so my word aint the word of god a reliable source would be carmack himself.

i guess we will know when rage goes live

[daemonicky]

Megatexture

I will try to classify it:
1. there is technique of texture atlas

• this atlas is part of megatexture technique
• even old games from 80ies used it http://www.icemark.com/downloads/index.html#Spectrum
• In case megatexture is composed of several textures: packing of several textures into one is nothing new.
• In case megatexture is just one continuous texture: there are techniques "draw texture directly on 3d model", for example Photoshop can do it, Blender can do it, 3D Studio Max can do it too ...

2. Carmack developed technique how to efficiently upload parts of texture if the texture is very huge (does not fit into card)

• it is the other part of megatexture technique
• I may be wrong, but it is possible that some of these old games used similar techniques of uploading parts of image atlas.

Speed:

• There are no texture state changes, right
• But there must be a cost of uploading new texture data into graphic card, right
• So, the cost of uploading that data is smaller than cost of real texture state change

Animations

Are all animations keyframe based By keyframe based I mean that you set key frame to either whole model or part of it.

From what part is involved in animation there are 2 classes, animation on all vertices at once and animation with groups of vertices. Animation on groups of vertices is either Forward or Inverse Kinematics. Is this correct Thanks.

[revelator]

collection of links about the feature.

upcomming versions -> id tech 5

http://en.wikipedia.org/wiki/MegaTexture

versions atm ETQW etc.

http://en.wikipedia.org/wiki/Id_Tech_4

perpetual drawback (holy hell) i suspect i will need a new harddrive

http://www.giantbomb.com/id-tech-5/92-1385/

[ArchAngel]

A question occurs to me... most texture formats use referential compression, so how do you read part of a mega texture? Does that mean you can't have any kind of compression on the image?

[revelator]

as far as i could read by using UV mapping and some other tricks.

i may be wrong though (not the first time).