• Hey, guest user. Hope you're enjoying NeoGAF! Have you considered registering for an account? Come join us and add your take to the daily discourse.

UDK Thread: Unreal Development Kit

Do you want to make a UT deathmatch map? A simple scene? A game of some sort?

If you provide no stipulations, I'm just going to pick something and be like "RISK BREAKER, make thou a farmyard scene with a barn and a silo. There aren't too many UDK scenes with barns and silos!" So there you go, get modeling. :p

I really have no idea haha, so I'll go with your suggestion, why the heck not :D Besides there are a lot of farms and stuff close to where I live so I'll have some guides.

I'll see what I can do and I'll post back with what I have. Thanks ;P
 
I really have no idea haha, so I'll go with your suggestion, why the heck not :D Besides there are a lot of farms and stuff close to where I live so I'll have some guides.

I'll see what I can do and I'll post back with what I have. Thanks ;P

And if anything about what you're doing confuses you questions can be asked here, or you can find tutorials on the youtubes. Most importantly, have fun.
 

(._.)

Banned
So I officially got to work on my scene today. Didn't do much apart from making my building model modular. Also messing around with units in UDK and 3ds max so this is scale to the character. Looking at that 3d motive tutorial.

RN7Wt.jpg


door shyt and windows are still WIP. Also not sure how to make a modular roof.

DsVyo.jpg


old pic for reference when it was mostly all one model.
 
That looks good :)

So, I have a question. A pretty simple one, I'm sure, but I haven't been able to solve it.

Say I had a Fluid actor emulating a river, I applied a material to it that kinda looks like it's flowing BUT it's flowing from left to right instead of up to down! I have to rotate it, how do I do that? I ended up rotating the whole actor, after trying to find something on the actor properties and after trying to apply the node Rotate (or something like that) to the material itself and it didn't work. It happened as well with the terrain textures and I'm pretty damn sure it's going to happen to everything I apply horizontally.
 

Blizzard

Banned
That looks good :)

So, I have a question. A pretty simple one, I'm sure, but I haven't been able to solve it.

Say I had a Fluid actor emulating a river, I applied a material to it that kinda looks like it's flowing BUT it's flowing from left to right instead of up to down! I have to rotate it, how do I do that? I ended up rotating the whole actor, after trying to find something on the actor properties and after trying to apply the node Rotate (or something like that) to the material itself and it didn't work. It happened as well with the terrain textures and I'm pretty damn sure it's going to happen to everything I apply horizontally.
Maybe it is related to UV coordinates? If you apply the material to BSP then I think you can rotate the UV coordinates in BSP properties itself, but I'm not sure.

For a fluid actor I'm not sure. I would THINK that you could probably make your own material and/or material instance that does the motion in a different direction, and/or has the UV coordinates swapped as the inputs go into the nodes. It's been a long time since I have actually messed with that sort of thing, so hopefully someone else can help you better.
 

Blizzard

Banned
Also, I thought you should all know that last night I dreamed Evilore posted in this thread. He posted screenshots and like, a link to somewhere that I guess had a video.

The screenshots and video demonstrated that a new version of UDK had fixed the portals not rendering through portals problem, and they actually had Portal style oval portals. PLUS, the portals and demonstration level looked exactly like Minecraft. Who knew UDK could render both Minecraft and Portal
in my dreams
!
 
Still haven't tried doing any of that as I've been doing some basic basic modelling on Blender. Once you read how the interface works, it's not that bad... But damn, if I had to figure it out by myself, not in a hundred years.

Cool dream haha, source style portals would be so cool :(
 

Blizzard

Banned
Still haven't tried doing any of that as I've been doing some basic basic modelling on Blender. Once you read how the interface works, it's not that bad... But damn, if I had to figure it out by myself, not in a hundred years.

Cool dream haha, source style portals would be so cool :(
They may be possible, and I'm pretty sure that portals can be rendered if they're static. I don't know if they can move. I can't really look right now but if you search around there are probably some fan attempts already at a portal gun.

I guess I mainly stopped worrying about portals and reflections since the performance cost of them seems to be so huge, making things seem sluggish and stuttery with even one or two reflection or image capture actors last I experimented with them.

There are some things that you might think would be easy, but then you try to do them. I tried to make some sort of X-ray vision effect like Batman detective vision, and it took ages of experimentation. I don't think I ever came up with something I liked, and I don't recall much helpful input from the UDK forum when I tried going there either, c'est la vie.
 
I guess I mainly stopped worrying about portals and reflections since the performance cost of them seems to be so huge, making things seem sluggish and stuttery with even one or two reflection or image capture actors last I experimented with them.

Definitely. I had a couple of those on a testing "map" and I was wondering why I had such crap FPS until I found it. Never again :(
 

Blizzard

Banned
Definitely. I had a couple of those on a testing "map" and I was wondering why I had such crap FPS until I found it. Never again :(
The thing is that you can have decent performance with them...as long as your resolution and/or framerate for the image capture actors is horrible, which in return makes the reflection looks bad. =P There are probably some tricks to optimize it but overall I can definitely see the advantages of cubemaps for that sort of thing unless Epic comes up with something amazing.
 

Plasma

Banned
The thing is that you can have decent performance with them...as long as your resolution and/or framerate for the image capture actors is horrible, which in return makes the reflection looks bad. =P There are probably some tricks to optimize it but overall I can definitely see the advantages of cubemaps for that sort of thing unless Epic comes up with something amazing.

One little trick you can use it to make the floor sort of semi-transparent and duplicate what you want reflected underneath it. You won't get the player reflections but it'll look like the floor is reflecting the room.
 

(._.)

Banned
How do I unwrap something simple like this without messing up how the UVWs look?

The way I know how to unwrap is.

1) select face I want. 2) hit palanr map. 3) unhit planar map 4) drag UVW out of the way so I can repeat steps for next face.

Thing is they UVW looks all skewed when I do that. How do I make them look all neat in uniform scale to the actual model?

bMBOi.jpg
 

Blizzard

Banned
Those look pretty much the same size to me, but I don't know your software at all. In Blender I would probably set some UV seams, eventually unwrap, and end up with a set of islands that are hopefully reasonable sizes.

Do you mean they look the same size, but when a texture is underneath them some surfaces on the model itself have textures that are stretched or compressed?
 

(._.)

Banned
I resized those by hand. When I hit planar map they become squares. I had to resize them myself and they don't really line up and some of them aren't exactly to scale to the face they go to.

I just noticed most UVWs are very neat while mine are messy. I think I'm skipping a step in unwrapping.
 

Blizzard

Banned
I resized those by hand. When I hit planar map they become squares. I had to resize them myself and they don't really line up and some of them aren't exactly to scale to the face they go to.

I just noticed most UVWs are very neat while mine are messy. I think I'm skipping a step in unwrapping.
Ahhh. Is there any sort of UV seam step in the process for your software? In my limited modeling experience you mark some edges as seams so the software knows how to split it up nicely (might be a different option than planar map, too?). I imagine you may have already googled some tutorials about it though.

*edit* Here, give these a shot:
http://waylon-art.com/uvw_tutorial/uvwtut_01.html
http://www.republicofcode.com/tutorials/3ds/texture_stealth/
http://www.republicofcode.com/tutorials/3ds/unwrap_uvw_mapping/
 

(._.)

Banned
I'm really not sure.

I'm a total noob when it comes to texturing/UVWs.

I did though just select every face and in the UVW editor went up to mapping > flatten mapping and it seemed to unwrap them all very quickly and lay'd them out nicely.

EDIT: found a video and he is talking about using stitch selection so there aren't weird breaks in the material.
 
Ugh, I remade my barn basic model and got it right how I want it (more or less, haha), even if it has a few more polys than it should.

Anyway, I kinda forgot about the collision. UDK's collision settings don't seem to work. So what's the easiest/fastest way to set up a simple collision for a static mesh with blender? Do I make the basic shapes I want and set them on the model? Can you simply "duplicate object"? I've seen something about ASE exporting and renaming those shapes as UCX_ but I don't even see where and I have no idea how to do the ASE stuff.
 

Plasma

Banned
Well at the moment it looks as though you're doing them all individually you could try pelt mapping instead and use the quick peel tool to straighten it all out quickly.

So select all your faces and hit the pelt icon.
http://i.imgur.com/NsYFE.jpg

Then when the dialogue pops up just press Start Pelt and then commit.

Then press the quick peel button and it should come out like this.
http://i.imgur.com/gdFx9.jpg

Now you can either resize to fit it in yourself or in the Edit UVWs window you can go Tools>Pack UVs and get it to do it automatically. Most of the time I find it is better to pack it yourself though to make sure you have the biggest space possible for it.
 

(._.)

Banned
Well at the moment it looks as though you're doing them all individually you could try pelt mapping instead and use the quick peel tool to straighten it all out quickly.

So select all your faces and hit the pelt icon.
http://i.imgur.com/NsYFE.jpg

Then when the dialogue pops up just press Start Pelt and then commit.

Then press the quick peel button and it should come out like this.
http://i.imgur.com/gdFx9.jpg

Now you can either resize to fit it in yourself or in the Edit UVWs window you can go Tools>Pack UVs and get it to do it automatically. Most of the time I find it is better to pack it yourself though to make sure you have the biggest space possible for it.

damn, this makes things go a lot faster. unwrapping aint so scary anymore. thanx
 

Blizzard

Banned
Ugh, I remade my barn basic model and got it right how I want it (more or less, haha), even if it has a few more polys than it should.

Anyway, I kinda forgot about the collision. UDK's collision settings don't seem to work. So what's the easiest/fastest way to set up a simple collision for a static mesh with blender? Do I make the basic shapes I want and set them on the model? I've seen something about ASE exporting and renaming those shapes as UCX_ but I don't even see where and I have no idea how to do the ASE stuff.
I think you can do the crazy export and renaming stuff, but the absolute fastest way to just get SOME collision working will be experimenting with the menu options in UDK in the static mesh properties/preview window. You can make it generate collision meshes of various degress from the simple (box shape) to the complex (mesh that will try to follow the shape of your mesh).

Eventually you will probably want to figure out how to export a collision mesh from Blender, and I might have written some super simple tutorial kinda thing on that, but I can't remember for sure. I would have to dig around the UDK forums searching for Blender (you might try doing that as well since I may not have time until after new year's).

*edit* I don't know if you can have more than one collision mesh for a single object. If anyone has advice about that please share it -- maybe it's better to make smaller modules and try to put them together, each with simpler collision meshes.
 
I think you can do the crazy export and renaming stuff, but the absolute fastest way to just get SOME collision working will be experimenting with the menu options in UDK in the static mesh properties/preview window. You can make it generate collision meshes of various degress from the simple (box shape) to the complex (mesh that will try to follow the shape of your mesh).

Eventually you will probably want to figure out how to export a collision mesh from Blender, and I might have written some super simple tutorial kinda thing on that, but I can't remember for sure. I would have to dig around the UDK forums searching for Blender (you might try doing that as well since I may not have time until after new year's).

I will do both, thanks :) I tried playing around with all the UDK options but even though some looked like were right, they wouldn't let me walk through the doors at all... I'll keep trying anyway.
 

Blizzard

Banned
I will do both, thanks :) I tried playing around with all the UDK options but even though some looked like were right, they wouldn't let me walk through the doors at all... I'll keep trying anyway.
You'd have to post screenshots of the UDK static mesh window with collision mesh preview toggled on (experiment with toggle buttons and menu options) to be sure, but I wouldn't be surprised. I think most/all of those default collision meshes don't work with convex shapes or shapes with holes in them so I really don't know the proper advice to give there. I'm hoping Mik will chime in with input on some of this when he wakes up. :p

*edit* I can't check youtube right now, but try these links:
www.youtube.com/watch?v=EcRzxKg-cGM
www.youtube.com/watch?v=spYVAlXgcSo

If that fails, you might try these search results:
http://www.google.com/#hl=en&q=+sit..._pw.,cf.osb&fp=4987996f857d60&biw=631&bih=670

Read this thread: http://forums.epicgames.com/threads/771315-How-do-I-set-up-a-collision-mesh-inside-Blender

It sounds like you should be able to have multiple collision meshes per overall static mesh, but it sounds like they should also be simple and non-convex (no holes, no C shapes) if that makes sense. I don't know the theory as to why though. I hope some of this helps!
 

Blizzard

Banned
Some quick additional searching seems to indicate that concave collision detection either would be more expensive and so the UDK doesn't do it, or else it wouldn't work with their algorithms. Anyway. Check out this page for some general stuff that may be useful about asset creation: http://www.chrisalbeluhn.com/UT3_Asset_Creation.html

Specifically, search for UCX and you can read what it says about collision.

Here are some more tutorials from that guy: http://udkc.info/index.php?title=Category:Chris_Albeluhn
 
Wow, thank you very much Blizzard. I've read your post and the forums thread, I'll check out all the other sources tomorrow as it's quite late here. But yes, it seems it doesn't go well with meshes with holes and mine has quite a few.

I think Mik was taking a plane to Spain these days, I hope he comes back soon too. Thanks once again! If I get it fixed tomorrow I'll post the results.
 

(._.)

Banned
yay. painted my first texture ever. one of many to come!

224c1.jpg


very simple piece of stone work. Does this look like stone?

The texture is 2048x2048

will I run out of space with textures that size?
 

Blizzard

Banned
yay. painted my first texture ever. one of many to come!

very simple piece of stone work. Does this look like stone?

The texture is 2048x2048

will I run out of space with textures that size?
Very cool. Looks stony. 2048x2048 sounds quite large for a small piece texture to me, but if you are using it in lots of places where the player will be near it, might be OK. I am guessing 1024x1024 or 512x512 is more typical for tiling material textures but I'm basically pulling numbers out of my hat. =P 4096x4096 or 8192x8192 might be theoretically possible but that's getting HUUUUGE and I wouldn't be surprised if some graphics cards had problems with those sizes.

At any rate just go with what you have for now. I'm guessing this is a fun/learning project for you and it's not set in stone anyway. If you run into performance or file size/memory size problems and want smaller textures, keep the original full-size image stuff on hand in case you change your mind, and just create downsized versions for experimentation.
 
Meh, after trying to install the ASE exporting addon for blender it made it crash and it wouldn't start up. I uninstalled and installed different versions, tried again and same thing. Soooo... I'm not feeling like blendering again any time soon, I'll just focus on the terrain and materials for now :/

I have a big question, how do I apply two UV modifiers to a texture on the material editor? Say, I want to apply rotate and bumpoffset but I can only use one of the two. I should keep things simple and I most likely won't use those two but I really want to know how can you do that.
 

Blizzard

Banned
Meh, after trying to install the ASE exporting addon for blender it made it crash and it wouldn't start up. I uninstalled and installed different versions, tried again and same thing. Soooo... I'm not feeling like blendering again any time soon, I'll just focus on the terrain and materials for now :/

I have a big question, how do I apply two UV modifiers to a texture on the material editor? Say, I want to apply rotate and bumpoffset but I can only use one of the two. I should keep things simple and I most likely won't use those two but I really want to know how can you do that.
Did you try exporting as FBX or whatever? I seem to recall there are two ways to do it and that might have worked fine for me. Just remember that with learning 3D modeling, especially with Blender, it takes some grief and learning pains to get started in my opinion. :(

Also, post a screenshot of your material node setup, since it might be as simple as chaining nodes, to answer your question.
 

charsace

Member
Meh, after trying to install the ASE exporting addon for blender it made it crash and it wouldn't start up. I uninstalled and installed different versions, tried again and same thing. Soooo... I'm not feeling like blendering again any time soon, I'll just focus on the terrain and materials for now :/

I have a big question, how do I apply two UV modifiers to a texture on the material editor? Say, I want to apply rotate and bumpoffset but I can only use one of the two. I should keep things simple and I most likely won't use those two but I really want to know how can you do that.

You tried the zip version of blender instead of the install?
 

Mik2121

Member
yay. painted my first texture ever. one of many to come!

224c1.jpg


very simple piece of stone work. Does this look like stone?

The texture is 2048x2048

will I run out of space with textures that size?

What is that supposed to be? It looks more la some dark grey metal or concrete, and you can quite tell apart the tiling, even though the texture is so large and the object itself looks fairly small.

For one, you should get rid of the light/dark value differences. You need some for the darker areas, of course, and also some slight variation.. but in your texture you got big dark spots that are what makes the tiling texture so easy to tell (ie. you can see it goes from 'light' to 'dark', then light again, then dark, then light, then dark).

You also need to work on the material itself (spec and normal) to make it look more like stone or whatever you are aiming for.

Oh and yeah, 2048x2048 for an object that doesn't seem to be that big, seems like a waste. It all depends on what the prop is, and whatnot. But if it's some sort of support frame, you'd like to add some wear details, etc.. and yeah.. take the texture size down most likely :p
Again though.. it depends on the scale of your level, how are you using that prop, etc.. there's no pre-made sizes and polycount.
 
You tried the zip version of blender instead of the install?

Yeah, I tried once but it didn't work either. I'll just delete everything except my .blend tomorrow and start from scratch :) Perhaps I should try the 32bits version.

Did you try exporting as FBX or whatever? I seem to recall there are two ways to do it and that might have worked fine for me. Just remember that with learning 3D modeling, especially with Blender, it takes some grief and learning pains to get started in my opinion. :(

Also, post a screenshot of your material node setup, since it might be as simple as chaining nodes, to answer your question.

I tried with FBX and I got the mesh itself on UDK and it's sitting there without collisions for now, as placeholder. I know about the grief and suffering, don't worry :p I'll get over it.

Let's see about that screenshot...

matupkl5.png


The river layer is linked to the diffuse and normal just to see the effects without updating the material. I want to have that rotator applied to both the normal and diffuse of the river layer but I can't do that if I use bumpoffset... applying rotator the bumpoffset node doesn't change the texture sample as expected.

Thanks in advance.
 
Hm, got an email and apparently the UDK December beta is available. Seems like the biggest change is a texture paint tool, "Allows you to paint textures on static meshes interactively in the level viewport".
 

Blizzard

Banned
The river layer is linked to the diffuse and normal just to see the effects without updating the material. I want to have that rotator applied to both the normal and diffuse of the river layer but I can't do that if I use bumpoffset... applying rotator the bumpoffset node doesn't change the texture sample as expected.

Thanks in advance.
Give this thread a shot:

http://www.polycount.com/forum/showthread.php?t=87261

It LOOKS like you should be able to chain the two UV nodes, and you might have to do one first and then the other if the result isn't what you want, but I probably haven't used the bump offset one much specifically.
 
Give this thread a shot:

http://www.polycount.com/forum/showthread.php?t=87261

It LOOKS like you should be able to chain the two UV nodes, and you might have to do one first and then the other if the result isn't what you want, but I probably haven't used the bump offset one much specifically.

Oh my god, you are right. I read that thread a couple of hours ago but I didn't fully understand, duh. I can just link the bump offset output to the rotator coordinate input and it works ;______; I can even use TexCoord!! *tears of joy*

This was a small step for mankind but a huge leap for a man. :D
 

Blizzard

Banned
Oh my god, you are right. I read that thread a couple of hours ago but I didn't fully understand, duh. I can just link the bump offset output to the rotator coordinate input and it works ;______; I can even use TexCoord!! *tears of joy*

This was a small step for mankind but a huge leap for a man. :D
Good work, soldier! It makes me happy when anyone gets things done, almost inspires me to go back to my project(s). :p
 

Domino Theory

Crystal Dynamics
Would this tool be good for someone like me who has no knowledge whatsoever about scripting, modelling, and so on (basically everything having to do with actual game design), but wants to self-teach?

I feel like just messing around with the engine, learning as I go on how to create MP maps, create actual encounters, etc.
 

Mik2121

Member
Would this tool be good for someone like me who has no knowledge whatsoever about scripting, modelling, and so on (basically everything having to do with actual game design), but wants to self-teach?

I feel like just messing around with the engine, learning as I go on how to create MP maps, create actual encounters, etc.

It's as good as the use you give to it. You can learn the basics of UDK (it will take you one or two days tops) and then use the BSPs (you will learn about them really soon) to create maps.
It's a very good tool for level designers that want to demonstrate their skills in an actual 3D environment. Just go ahead and start placing boxed to create all the floors and walls, set the lighting also if you're into that too, and then create a build out of it and start to test it out. You don't even need to put materials on it (it all has a default check pattern) so you can jump straight into level design.

Adding enemies and creating encounters is a bit trickier, but it can be done as well.

Of course, you could also try and use the assets that come with UDK, but if you don't want to, you can just build everything out of boxes as I said. It shouldn't take very long. Though you will want to first plan everything out on paper so you don't get stuck all the time.

Oh, and work on the grid! Much easier to have everything fit nicely, and if the level were to be populated by actual 3D assets, it would be much faster.

Anyway, go to the videos I put on the OP and check the first few '3D Buzz' videos (User Interface, Simple Level, Lighting and Geometry Mode)
 

Blizzard

Banned
Yeah, even someone unfamiliar with everything should be able to put together some simple BSP geometry with lighting, and throw in a few of the default assets, within a couple of days as long as they are patient and reasonably comfortable with using a computer. :p

When you get into actually making a game, or doing complex scripting, or adjusting game mechanics, or doing advanced effects, or (especially) making lots of custom 3D models, THOSE can become very time-consuming. You can learn them all too but I recommend the basics as Mik said first.
 
It really is time-consuming, but it also is pretty satisfying. I, for example, want to know how to model, animate, texture, shade, script, UDK-ing :p and even basic sound design. I know it's going to take a looong time but at least you can jump from one thing to the other when you don't feel like doing something in particular.

I remember back when I wanted to learn 3D modelling, you couldn't really do anything with it on a game environment unless you modded some game and even then you needed some kind of deep coding knowledge to even get things running. It seems a lot easier nowadays, and a lot faster to get some direct results.
 

(._.)

Banned
starting 2012 my new years resolution is to do around 1-2+ hours work a day in 3ds max and UDK (or other engines). I am very confident I can become skilled with these softwares but I need to start building my portfolio up for when I apply in two years.

SO yeah, gonna spam this thread up pretty often with preview pics or w/e I'm working on. Hopefully posting stuff here will keep me active cause I haven't worked much over this break (planned to do A TON but haven't so far). was pretty active during the school year in the college forum posting class work and giving feedback to other students so maybe GAF will motivate me.

everybody get active and start workin with me win 2012 :)

BTW how much did you spend modeling in your free time mik before getting a job?
 
everybody get active and start workin with me win 2012 :)

I'll try :p

I have insanely large lightmass building times because of a single mess, a bridge static mesh that comes with UDK on top of a river. It takes up to 46% of the build time and I've tried disabling its shadows just to see if that's the problem but it doesn't work.

I have some ideas to try for the scene but that kind of problem is always slowing me down :p
 

Fezan

Member
starting 2012 my new years resolution is to do around 1-2+ hours work a day in 3ds max and UDK (or other engines). I am very confident I can become skilled with these softwares but I need to start building my portfolio up for when I apply in two years.

SO yeah, gonna spam this thread up pretty often with preview pics or w/e I'm working on. Hopefully posting stuff here will keep me active cause I haven't worked much over this break (planned to do A TON but haven't so far). was pretty active during the school year in the college forum posting class work and giving feedback to other students so maybe GAF will motivate me.

everybody get active and start workin with me win 2012 :)

BTW how much did you spend modeling in your free time mik before getting a job?

When you do also start posting tutorials where you learn from :p
i have taken a project which involves udk & modelling plus scripting.will start working at the end of jan
 

Mik2121

Member
starting 2012 my new years resolution is to do around 1-2+ hours work a day in 3ds max and UDK (or other engines). I am very confident I can become skilled with these softwares but I need to start building my portfolio up for when I apply in two years.

SO yeah, gonna spam this thread up pretty often with preview pics or w/e I'm working on. Hopefully posting stuff here will keep me active cause I haven't worked much over this break (planned to do A TON but haven't so far). was pretty active during the school year in the college forum posting class work and giving feedback to other students so maybe GAF will motivate me.

everybody get active and start workin with me win 2012 :)

BTW how much did you spend modeling in your free time mik before getting a job?

Go ahead and spam the thread, we need more activity around these places!.

As for me.. well, I would sometimes spend 6+ hours starting on the evenings, having done also stuff at school. Not everyday of course, some days I'd spend them just relaxing and whatnot.. trying to prevent any kind of burn-out effect. But yeah, on average something above 3 or 4 hours a day, with some days spending the whole day (usually during summer when it's so hot you can't sleep, and before you know, someone in your house is already having breakfast...), some days I would take a break, go out and get some references or just chill out. But a lot of hours, definitely. Many of them spent practicing things I'd find online (I still do it) instead of actually working on the portfolio itself.
 

Blizzard

Banned
I look forward to seeing the result of people's projects this year. :)

I'm not making a formal resolution but I would like to get back to working on some simple projects, especially the one I made up a schedule/design document for.

As for lightmass build times, that's very unfortunate. It makes me want to completely disable lightmass, and I think I actually did that in the last project I was working on, just so I could have quick build/test times. Of course if you are trying to make a nice-looking level then you will have crazy times...which is why it would be amazing if the UE3 and UDK ever got a Crytek-like dynamic lighting solution...but I suspect that will never happen since it would probably be too huge of an engine change or something.
 
Top Bottom