Yeah, I had to.
I know not everything about Unity3 has been revealed yet.
But I am personally excited at the prospect of creating Pro-Quality games with Unity 3’s new features.
I know this can be done NOW, but any additions of course make the deal even sweeter.
How about you?
Unity 3 vs. UDK.
Go!
Well you are asking it on the Unity official forums, what do you expect? 
Unity because it has never seen before cross platform and deployment options. Is very easy and fun to use. Has a variety of scripting options. Can import almost all the well known files for every media. Continously improved. Unity staff, they are the nicest guys I have ever seen in game dev. business. Every update makes me say “I wanted this since I started game development!”
I can list more and more things I love with Unity though so much love can get some people sick…
There is no vs for me.
If I would do a shooter or multiplayer shooter it would be Torque VS UDK, where you go depends on your need of low level access and your willingness to invest the money into a team to usefully unleash and utilize something like UDK as you can no longer handle a monster like that with a 2 person dream for more than “prototype” / “indie contest” usage out of my sight
For anything else its Unity, especially when its about more than just windows only distribution, as that is the only thing you can do with UDK
I personally care only little about the deferred rendering of Unity 3. For me the upgrade of mono to finally get professional development functionality and the required stability, the upgrade of physx and the integration of beast but especially umbra (PVS is the major optimization aspect ignored in Unity 2.x, closely followed by the UI, but there GUIX closes the gap easily)
you can learn a lot from this thread too
Is Unity any easier than UDK?
http://forum.unity3d.com/viewtopic.php?t=36040
Is difficult to compare Unity and UDK because they are extremely different, unity is a indie engine for iPhone, Apps, web Apps and stand alone mac and window applications therefore made with low quality settings in mind, UDK is a resource heavy, state of the art engine subset of the 1 Million dollar worth unreal 3 engine and UDK is only available for high end pcs. As you can clearly see they are completely different beasts.
The BIG problem about UDK is that is not designed for small teams with small budgets, if you want to create a free modification or minigame of sorts using it and you have every intention to make it completely FREE then you should definetily try it, specially if you are interesting in entering the proffesional (not indie) developer industry later on.
However if you even think in releasing a commercial game with it, you should reconsider, the price of entry is almost the same than unity pro ($99), but you have to pay 20% royalties of ANY MONEY made from the game, not just directly from sales, that includes: advertising (google ads), grants, publisher deals, loans EVERYTHING pretty much is like adding epic to the pay roll. Unless you have a cool million lying around to buy the whole thing, so you can stop paying royalties.
Probably for a large company thats no problem but for a small team barely making a living 20% of your revenue can and probably will break you. (you could even end up in debt)
If you are an accounting/manager god with a team than knows their way with ease around the engine, and you have a great idea that can profit a LOT from its use, then by all means. Otherwise stay away.
And the UDK licence - 25% !!!
Hmmmm …
Unity 3 should have the new lightmapping features and render-to-texture in the indie version tho
The reason I stopped using the UDK is because it’s practically undocumented. When I use Unity I just open up the API reference in a browser window, #unity3d in my chat client, and I’m set.
When I use the UDK it’s like I’m all alone in a maze of features.
Unity Indie ceased to exist in autumn 2009
There is only one free license (Unity) and one payed license (Unity Pro)
UDK != Intuitive
I took a course at college in computer graphics that used the Unreal editor and the UT2004 version of the Unreal Engine(Unreal Engine 2?) Anyhow, that software is crazy, ctrl-s does not save your level, it subtracts the current geometry from the level with no undo! There are numerous other wonky things that hopefully they fixed, but when I used the old Unreal Editor it was a nightmare.
UDK is good for big budget large team developments that can invest in such technology and only want to produce games for top of the line pc’s.
Unity is allowing me as a single person and no money create a game! How awesome is that! I can even sell it and take all the profit so long as I dont exceed $100,000/yr(anything more requires pro license) if I remember correctly. And all the tools are easy to learn/very intuitive. Unity is great for small to single person dev teams. It also has cross platform and web deployment. It’s growing to support more and more platforms and runs on almost any hardware configuration.
Unity is the do all run almost anywhere game engine.
UDK is the high end gaming pc only market.
I’m sorry but look again, you clearly were not looking close enough! The one major thing that the UDK has over every other 3D engine out their is docs. May be you looked when it was first released I do not know, but now it has eclipsed unity, torque etc many times i.e buzz 3D, eat3D, the udn and 100’s of hours on youtube and scattered on private web sites across the net.
I like the editor in Unity much more than the UDK (which I find a bit clunky) and the asset pipeline is really easy to work with, my major gripe with unity is networking and lack of docs for scripting. These are big head aches for me (may be not for you 
) but I have found the opposite to be true of the UDK. I am not saying any engine is better, both have strengths and weakness.
Which you choose will depend entirely on your project but people please stop saying that UDK requires a massive team, has no docs, is only for large commercial games etc this is simply not true! The UDK is just as fast and easy to use as Unity (although will take you a little longer to learn it because their is so much). $100 and 25% on anything over $5000 might be too much for some. In these cases Unity is def the best option and you should run with it, the guys here do a fantastic job.
Sorry for the rant but these threads are pointless, comparing apples and oranges and filled with miss information. I use both and I am quite happy with both, they each have a place in my heart
Cheers,
Jiff
Just 5 threads down you can find a 23 page thread named : Is Unity any easier than UDK? Ofc, everyone compares the two instead of offering tips. NO need to go there again.
http://forum.unity3d.com/viewtopic.php?t=36040
Just to add something useful to this thread:
As it is right now, leaving all else aside, the UDK has rock solid networking support, a HDR rendering pipeline and integrated Steamworks(darn) over unity. The community is in it’s infancy stages from what I gather over at their forums but is shaping-up quite nicely.
Unity has multi-platform support and an indie-friendly workflow (fancier dynamic lighting system too).
Both binaries have a lot (and by that I mean a lot) of docs, both video and text, free or paid. Both sides should do their homework on this.
Bingo baby
I come from UDK, and I have to say, this is far better. Although, its not impossible to make something good in UDK. The reason I switched, is because in UDK, you have to exit out of your engine, write your script, recompile with frontend, restart the engine, and test. While unity does this all really fast right as I save.
I won’t learn another engine unless I have to (and with unity I had no reason to switch)
This is critical. You will make a better game with a so-so engine that you understand well than a great engine you don’t understand at all.
The difference between Unity and UDK is like the difference between a sailboat and a navy carrier. Yeah, the navy carrier is going to be better than the sailboat, but unless you have a team big enough, and trained enough to man it, its useless. If your team is between 1-6 guys, and you don’t have a huge budget, probably best to use Unity.
That’s a hell of a quote.
I second that!
I don’t get why people say the UDK isn’t friendly for small teams, just look at the unearthly challenge, people had 8 weeks to make a level with the theme end game (and most people had full times job while doing this challenge). I believe most teams used the udk.
Unity 3 wins