Doom3world

Some time ago I decide to play this game and I must admit that I like singleplayer even with all those console style features like glowing shit, tips, and giant hud medallion - but it is not the subject of my question (I will have to try neurowolf mod).
I would like to ask You, do You know why and how, idtech engine in this game is bit faster than same engine in other games like D3,Q4? and why textures are sometimes sharp and sometimes just after entering new room very blurry low quality?

The speed increase is due to the use of differed shading, and the blurry textures are a result from the use of texture streaming (think UE3).

so it is like Doom3 load all textures to computer memory from playing level while Wolfenstein first load level map geometry and after start load more textures depend on what player see?

D3 & Prey are the only D3 based games that I know of to load all the textures in to memory. ETQW, Q4 (I believe, not 100% sure) & Wolf use progressive loading. I'm assuming Brink (the newest D3 tech game) will be the same.

Wolf SP Was a blast imho. But to easy & no mecha-Hitler.

I didn't find it any faster in FPS compared to D3, Prey, Q4 or ETQW. The reason I would say it's faster is because the min requirements were higher then D3/Prey, it came out years later &, most likely, you have a better computer then when you first played D3.

I play all those games (D3,Q4,Prey and now Wolf) on my Lenovo laptop and believe me - it's not powerful machine. Last time I add some memory and noticed that now loading screens are shorter in D3. It also look like Rage will also use that technique with quick loading textures. It's hard to say is it good or bad, for me it's bit different from what I was used to. I like when game load all stuff fast, but I do not like when game show me often graphic glitches.

Texture streaming is mainly done because of console memory limitations, hence why it's prevalent in UE3 games and is used in Wolf (UE3 also streams geometry. Dead Space 2 used this well to make the entire game seamless). Q4 doesn't use texture streaming and neither does ETQW (the megatexture is streamed, of course, but it's a little different). In in the case of Rage, when you virtualize everything, there's no other way to do it.

Thanks for answer, now I know what I was curious about.

etqw didn't have streaming

Pretty sure Q4 had a hard budget too.

Megatexture is streamed, ETQW uses Megatexture, ETQW has streaming of terrain textures. The only use of streaming something is if it's not being used, with majority of everything else being always on screen it's not much use to stream characters, vehicles, model, etc. textures.