Armagon917: don't know about that. Both idTech 3 and 4 haven't been very successful w.r.t. licensing to 3rd parties.
idTech 4: only 1 3rd party game: Prey
idTech 3: not more than 15
Maybe idTech5 will change that.
Also the difference between Doom 3 and GoW1 is quite large. But yes, id and epic seem to alternate in engine generations. UE3 is getting mature, and the new kid on the block will be idTech5. But right now, there is no idTech5 to be licensed, and UE3 is here to be used. I don't know how well idTech5 will cater the next generation of console hardware. But by the time idTech5 is released the next generation of consoles will be in development, and so will UE4.
id tech 3, 18 actually, lol.
i see what you're saying between DOOM 3 and GoW1. there are a slew of features that GoW is using that id Tech 4 doesn't support. motion blur, HDR i think, Parallax and occlusion mapping which for us artists is the big one IMO.
i know that Unreal Engine 3 has much more under the hood than id tech 4 but if you were to look at the assets used and real world application id Tech 4 is not far behind in the terms of how Unreal Engine 2 completely sunk id Tech 3. well I guess its a matter of perspective being difficult to guage and compare the leapfrog for lack of a better term of the last generation engines.
i actually think that id Tech 5 is aimed at the current generation consoles as it was up and running on both PS3 and 360. id Software has huge development cycles that compete with Blizzard so who knows when the tech will be available. but the reason i am specualting id Tech 5 will become the dominant tech to develope with is mainly because of id Software's behavior on this as well as some of the tools i've seen. in the past id has mainly completed their games and licensing was treated like an afterthought almost. id Tech 4 is a great example of this. obviously an engine made for close quarters high detail environments like DOOM 3 for its time.
the difference is that this is the first time id has come out and shown tools when they first showcased their engine. i can not recall any other time. so they are really marketing this as something they want to license as opposed to near exclusive focus on their own projects. features such as being able to work on a level over a network and have another artist is working in another area and having that show up in realtime allows for really efficient workflow along with other tools i mentioned before. as an artist it appeals more to me. all speculation though how this will turn out.
i think that these engines will be very close with certain strengths to one or the other. i think stability and tools will determine a winner as lame a term as i find that for this, mainly because of increasing development cycles. sorry for the blog.