For anybody that loves/wants FULL dynamic light & shadows in their UDK game!

[shuriken88]

I always thought, and was told, that it was pretty much impossible to have true dynamic light and shadows in UDK/UE3, which was one of the most disappointing things I'd ever heard about the engine. I dont know about you, but I've always believed that dynamic shadows are one of the most important and immersion enhancing graphical features in gaming, ever. You take ANY game, especially a game with an edge of horror or suspense, and add dynamic shadows, and it instantly becomes twice as deep and atmospheric. A game like Deadspace, Condemned or even Skyrim (if it were feasible) with full dynamic light would be unbelievable IMO!

Anyway enough of that. A while ago, a guy on youtube proved all the skeptics wrong and showed that it WAS possible to make EVERYTHING cast dynamic, moving shadows, (even BSP ffs!). All you have to do is create a light that will move and cast the dynamic shadows, then go into the properties and untick "cast static shadows", then under "channels", make sure "dynamic" is ticked. Finally, goto "LIGHT SHADOW MODE" and change it from modulated, to "NORMAL" (this is the key), now tweak the resolutions to your liking. I tend to go no lower than 1024 for all 3, but I haven't tried lower so just experiment. You will also need to setup any static meshes to cast dynamic shadows too (basically the same process as the light).

Now make sure your light is attached to your player, or setup in a way that it will move in some way if it isn't a flashlight (like maybe a swinging light, or a passing car etc), and hit test. Now you've got FULLY dynamic shadows in UDK, and the performance doesn't even take any major hits!!

I couldn't find the original youtube video that I learn't this from, so I cant credit him here, but I cant thank him enough, because he basically showed me how to circumvent the biggest gripe I have with UE3. The guys a legend! I just want to pass on what he taught me to anyone else who thinks dynamic shadows are a nessecity in creating a believable atmosphere!

peace

[darthviper107]

You're misunderstanding the caution against dynamic shadows--UDK can do dynamic shadows just fine, the problem is it can't do a lot of them, and in most cases you don't need to with lights that don't move. Doing a main light and a flashlight both with dynamic shadows is just fine, doing every light with dynamic shadows is not.

[shuriken88]

Yea I've only been using a single dynamic light in my maps so far, but I just find it almost mouthwatering how everything you can see, is capable of casting moving shadows. I love it! Sometimes its a little bit glitchy, but I put that down to my own errors, like my light intersecting with meshes causing shadows to vanish and reappear.

I made a map using meshes I made purely in Max, which is a huge castle (so far only the front face of the castle), with a partially finished interior made of a maze like set of modular, claustrophobic corridors with staircases, junctions, rooms etc, and the character has a "fire coloured" light attached to him, and it looks great walking around the corridors, especially in 3rd person. I did another map set in a garden in a futuristic japanese city where you have a path surrounded by tall trees, leading up to a throne, and along the path there's shrines and those "Japanese arches" (forgot what they're called), and those little oriental bridges. In the background theres a few towering futuristic buildings with lit up windows. Right now I'm trying to make a horror themed level. Being able to use dynamic light like this is so much more inspiring! I could post some screens of the levels so far cos I really enjoy modelling everything then seeing it come to life in UDK!

[Crusha K. Rool]

Or just uncheck "Use Precomputed Lighting" in the properties of the StaticMeshActors that you want to cast dynamic shadows. In the WorldInfo properties under "Lightmass" can you then also check "Force No Precomputed Lighting", rebuilt once and get an optimized result for levels with full dynamic light.

[Neongho]

I think that a good game is made of code , not of images .
As more things can heppend on it better game is.
That's a 1 % of what you can make happend on your game, with this engine you can make easily get in your game a lot of diverse and dynamic gameplay.
Example , Minecraft. slender... and mucch others that they don't have Crysis graphics , people thinks that just because graphics are awsome a game it's meant to be good or bad... lol.
Timers and states and other functionality are awsome , enough to leave without importance that fact of the "dynamic Light".

[shuriken88]

You misunderstand me man, because I'd be the LAST person to judge a game, purely on a visual basis. I wasn't saying that graphics are everything, but in this thread I'm only talking about the graphical elements of a game, because the topic of the thread has nothing to do with gameplay mechanics, so theres no point talking about something irrelevant. Those games I mentioned are great as it is, but with dynamic lighting, the atmosphere would improve immeasurably IMO. If you disagree, thats your perogative, but I for one love the effect, and if a particular games engine can handle it without choking, then it should use it, to the fullest extent.

In any conversation or discussion about graphics VS gameplay, you'll find that the only view I have on the subject, is that if you haven't struck a succesful balance between the two, then its not going to happen. I also consider myself a retro gamer, and retro gamers & graphics whores are like polar opposites, so there you have it.

Minecraft (I can take it or leave it, it didn't really appeal to me), and Slender man, well, if we're thinking about the same slenderman indy-game (theres more than one), then it was okay from what I could see. To prevent confusion, I'll say that what I'm making isn't a game, its a collection of maps & scenes that started off as visualisations in my head. Im not a programmer, Im an artist per say, because I only deal in the visual side of things, whether it be level design, character/weapon/vehicle design, and also game design in the written sense, and story/script/plot writing.

[Neongho]

Why you write so many sentences ?

Why don't you say , Hey i think like you , then Yep minecraft and slender they're good , and then im oldschool gamer man i hate reading sentences with no value.

The point im defending it's this one , if they haven't added it yet it's because they probably have some problems ... with whatever.
Probably performance , "unrealscript" it's slow .... i don't remember why but yep some times more than direct c++ , i'd like to certanly know why .

[JessieG]

Dynamic shadows have performance limitations. Plain and simple. Is it doable? Absolutely. Will it run good? Probably not.

[Shindawg]

Why you write so many sentences ?

Why don't you say , Hey i think like you , then Yep minecraft and slender they're good , and then im oldschool gamer man i hate reading sentences with no value.

The point im defending it's this one , if they haven't added it yet it's because they probably have some problems ... with whatever.
Probably performance , "unrealscript" it's slow .... i don't remember why but yep some times more than direct c++ , i'd like to certanly know why .

Maybe it's a translation thing, but you're being kind of a ****. He writes so many sentences because he's trying to actually make sense and get a point across. If you can't manage to read 3 short paragraphs then you're in serious trouble. However, I agree with the point others have made - that it's always been possible to do dynamic lights but it's never been advisable due to the fact it can make your game seriously chug if not done properly (basically what JessieG said).

[ambershee]

Unreal's renderer doesn't like having a lot of dynamic lights. With one or two sources, you're usually fine, but in my experience once you have more than that, performance begins to wax very quickly. I suspect Dx11 rendering doesn't have quite the same performance hit using standard dynamic lights.

[Ehamloptiran]

Unreal's renderer doesn't like having a lot of dynamic lights. With one or two sources, you're usually fine, but in my experience once you have more than that, performance begins to wax very quickly. I suspect Dx11 rendering doesn't have quite the same performance hit using standard dynamic lights.

As per this UDN entry http://udn.epicgames.com/Three/DeferredShadingDX11.html The DX11 renderer uses a Deferred rendering approach, which allows for a lot more dynamic non shadow casting lights. Your still limited by the number of dynamic shadow casting lights than can be placed in a scene before performance drops big time. The important line to read in the above UDN entry is:

"Lights rendered with deferred shading are about 10x faster than lights rendered with forward lighting. In the GDC 2011 tech demo, the intro scene had 123 dynamic lights, and all lighting was done using deferred except on character skin and hair. Note that deferred shading does NOT speed up dynamic shadowing, which is already deferred in UE3, so this does not allow you to have hundreds of dynamically shadowing lights."

I have created a scene that used 85 non shadow casting lights and one shadow casting light with a good amount of geometry and post processing with good performance. That was on a Intel Core i7 2.66Ghz with 16GB ram and a NVidia 590Gtx graphics card

[ambershee]

Good info there - cheers