I started making levels a few weeks after seeing Doom for the first time... I didn't have a Doom-capable machine at home yet (94-95), so this all happened at my school that had just got two new P90's...
I pretty much stopped making Doom stuff when I learned Quake editing in late 1996 (Bought a new computer that X-mas, too).. I didn't completely "break up" with Doom, though.. For example I did two levels for GothicDM when I was already getting fame for my Quake maps.
2) I've seen your and Adelusions name in several add-on's. When did you start working with Adelusion?
Early, very early... I had just released my first ever single player Doom2 level (mines.wad) to the net, and Adel was searching for another good author for Dystopia3... He saw the level on Thomas Giboney's Doom2 Project page and asked me to join. (Mines is still one of my favorite maps of my own, btw)
3) Adelusion said that if he has a value of best DooM level designer, then you should share that value with him. Any comments about that?
When I last saw a voting for the best Doom level author, we two did share the first place. :-) Well, I guess I wouldn't call myself the best Doom level designer now that I'm no more active on the scene.
4) You moved away from DooM editing. What were the main reasons?
I was very impressed by the virtual limitlessness of Quake engine. Contrary to my earlier fears, it allowed good level detailing on acceptable speed despite the more complicated nature of the engine. Also it made more different combat situations, connections between places, etc possible than in earlier engines... (Although id maybe didn't make perfect use for all the new possibilities)
Also, I can't leave QuakeC unmentioned. With QC, people could virtually make their own games out of Quake engine (Which was what I wanted to do, and eventually did [AirQuake]).
5) Do you still play DooM?
Very rarely... I have been checking out some new Doom versions like the Doom Legacy, though. And taking a look at Gothic2 was a must, of course... :)
6) Are you going to release any DooM levels in future? Or _any_ non-commercial levels?
I have one unfinished Doom2 deathmatch level on my hard disk, we'll see how it turns out :) For other non-commercial levels, I sometimes do Quake2 levels on my spare time. (Released my latest deathmatch map ikdm4 a few weeks ago at http://www.planetquake.com/ikq/levels.htm)
7) When you make a level, do you just start it from the scratch and edit it until you are finished, or do you plan it before actually starting editor?
When I was making stuff for Doom, I often planned the level precisely on graph paper before even touching the computer... Due to the 3d nature of later engines, it's not that easy to plan them on paper anymore, but I roughly plan the layout, connections between places, player's moving path and sometimes some details or a room...
8) Some of us can make a good level in less than week and some of us take over month for one level. How long it usually took from you to make a DooM level? Or Quake level?
It depends on the size and style... My fastest Doom DM level took 14 minutes to make, and I guess my largest single/coop took a month or so. Actually there's not much difference between the time it takes me to do levels for different games. Although Quake engine levels need more complicated geometry, the editors are more visual and have a lot of helpful features that speed up the editing..
9) Which one of those DooM add-on's that you have been making levels to you consider to be the best?
Requiem. It was the ultimate episode... Unfortunately we got stuck with the last 2 or so levels that combined with other problems delayed the release by almost a year. :(
10) Was it just my imagination or did I see one of your levels in two different add-on's?
Hmm, could you please tell me what level and what add-ons? As far as I remember, I only re-used Mines by myself... (first a single map, then map07 in dyst3 with added monsters)
(I propably just saw the mines.wad and dystopia3.wad :) )
11) What do you think that are the most common mistakes of new level designers?
Trying too little or too much... Typically beginners either make something completely plain and undetailed (and don't align their textures), or start making "the ultimate cathedral level" after their first one-room test map, and run into engine limits when the first space is half done... There are also some things you can only learn by experience, such as sense of scale and proportions, consistent texturing and architecture style, etc.
(That's VERY true... Reminds me of my first own level experimentings :) )
12) What's your tip for those level designers that would like to earn some money with their talents?
I suggest getting in touch with the latest engines like Quake2 and Unreal. Those are what companies are using now, and they hire people who can use these engines rather than ones who would have to learn everything from the basics first.
(I recommend Unreal... It has so powerful engine that nobody will be interested in Quake 2 engine anymore :) )
Last question: What would you like to say for those DooM level designers that are still around?
I think you're all damn freaks sticking to Doom like that, but I guess you love it so who am I to say anything? :)
(True. We are quite freaks, ain't we? I know that I am... Just can't stop DooMing :) )