Does anyone know Tutorials on how to make GOOD lighting in unreal? (LONG)

Count Vader

So, there's a wealth of tutorials out there on how to light in Unreal, but all of them focus on stuff like, how to lay out your lightmaps, what the difference is between a static or movable light, what lightmass actually does and the different parameters and lighting settings.

I can't be the only one, who, having armed myself with this knowledge proceeded to move on to light a scene in Unreal, only to promptly end up with utter trash. I know this probably verges on more abstract/artistic than technical, but I'm posting it here because I don't have a relevant scene to show right now, and generally stuff I post in the art forum mostly gets ignored anyway :P

So, yeah, are there tutorials out there that address concerns like:

How many lights is it sensible to have in a scene? I am aware of the 3-point lighting principle, so with that in mind, do you try to only place lights where there are 'real' light sources in your scene, or wherever you want/looks better? If you want good rim lighting for a specific object, do you assign it its own light that is excluded from all the other actors? How do you deal with the inevitable mess of maintaining lighting continuity/web of lies in a scene like that?

How to treat emmisive objects such as lamps and lights (aka objects that would be generating light in real life)? How much to rely on the 'emissive' contribution from their textures, and how much on the light actors you are placing where those objects are? Do you supplement emmisive textures with light actors? If so, how does one determine how much contribution each respective lighting method makes?

How to just generally have 'physically correct' lighting in a scene. Is it mandatory to use specific IES profiles? Do IES profiles do anything beyond changing the shape of light cone? Do they enable 'more physically correct' falloff? Do you need to work within specific units for IES profiles to meaningfully improve your scene, or do they work with the default unreal units (aka assuming ~96 player height or whatever it is)

I realise that, as lighting artist is its own job, that to a degree, this is kind of like asking 'how do I create great game art' when in fact doing so takes tons of practice and knowledge, but there's gotta be some sources that address all this stuff to a point where you can get out a decent lighting bake.

So, TL;DR
how do i get a level of quality in my lighting comparable to this :

Ootrick

Agreed! I'd love to see some practical tutorials that show how use use lights for situations. I've seen tons of tutorials on X light does this, without much application. I've torn through lots of tutorials / forums burning cash and looked at Demo scenes in unreal. I haven't noticed much consistency when it comes to formulas and applications of lighting  for large or small, interior or exterior scenes.  Of the scenes I've checked out in engine the lighting setups have been so different. Some large amounts of lights and low captures/environment, others the exact opposite for the same type of scene. I'll post what I come across, if anyone knows of some good material please share! 

McGreed

Yeah, I was looking for tutorials as well on https://wiki.unrealengine.com/Videos, and funny enough there is none about lighting. I do have a tutorial disc from Eat3D about lighting for UDK, which I guess would work for U4 as well; http://eat3d.com/udk_lighting

cman2k

I am only just beginning to dip my toes into this subject as well.  However, the example you posted is from Koolas, and he has a thread on the Unreal forums where he posts some details.  It's almost become an ongoing discussion of how to achieve these types of results, with lots of people asking the same questions you are.  Have you taken a look?

Not a tutorial per-se, but the info may well be out there if you can parse through and find it.
https://forums.unrealengine.com/showthread.php?28163-ArchViz-Lighting

Count Vader

@McGreed Yeah, I actually remember watching the eat 3d one some time ago, think I still have it. I don't remember getting much out of it, but I might go back and take a look, I could have just zoned out on it since eat3d stuff usually puts me right to sleep lol.

@cman2k Good call haha, I saw the thread, but didn't go through every post. As far as what I got out of it, the guy just cranks his lightmass settings way the hell up, but I suspect there's more to it than that. I will go through it more thoroughly and see what else I can get out of it.

ZacD

From my experience, how you approach a scene really varies depending on your goals, is it indoor or outdoor? Dynamic or static? Time of day? Arch vis? Mobile? VR? High end pc? 

If you are using light mass, download Koola's scene from the market place. Those bounce cards work well, use them if you need some lighting. use emissive materials for baked lighting is a bit hit or miss, I would either not use it, or combine it with actual lights most of the time. Baked skylighting by itself can look really nice. Avoid having too many seams, especially if they aren't in natural places or covered up by textures or meshes. Lightmass can leave seams even if you try to do everything right, if you you want to do something modular, have pillars or corners or texture seams where there could be lightmass seams. Or use one giant mesh for a wall instead of 10 repeating ones. Don't be afraid to use tons of lights and unrealistic lights, use them to make light follow your will. IES profiles are really only needed for arc vis and can be added at the end, they wont make the lighting better, but they can make it more interesting. For a lamp, make the bulb a separate mesh, set it to not cast shadows, and put the light in it. Or you can put it over or in front of the actual light if no one is going to be able to tell the difference. You don't need to worry much about having "physically correct" lighting, but there are a few physically correct suggestions on the UE4 forums for values to use for certain wattage lights, the sun, and the skylight for emulating real life. 

You don't really need to play around with all of the lightmass settings and values, the main thing is putting Indirect quality to 4 for your final bake. If you want to just tweak specific things playing with those settings may help, but it's not going to change bad lighting to good lighting. It's follow the scale units in UE4, otherwise the lighting wont behave as it should.

Distance Field AO/GI and Height-fields are really only ideal for outdoor scenes like the Kite Demo or Fortnite.

Count Vader

ZacD said:

From my experience, how you approach a scene really varies depending on your goals, is it indoor or outdoor? Dynamic or static? Time of day? Arch vis? Mobile? VR? High end pc? 

If you are using light mass, download Koola's scene from the market place. Those bounce cards work well, use them if you need some lighting. use emissive materials for baked lighting is a bit hit or miss, I would either not use it, or combine it with actual lights most of the time. Baked skylighting by itself can look really nice. Avoid having too many seams, especially if they aren't in natural places or covered up by textures or meshes. Lightmass can leave seams even if you try to do everything right, if you you want to do something modular, have pillars or corners or texture seams where there could be lightmass seams. Or use one giant mesh for a wall instead of 10 repeating ones. Don't be afraid to use tons of lights and unrealistic lights, use them to make light follow your will. IES profiles are really only needed for arc vis and can be added at the end, they wont make the lighting better, but they can make it more interesting. For a lamp, make the bulb a separate mesh, set it to not cast shadows, and put the light in it. Or you can put it over or in front of the actual light if no one is going to be able to tell the difference. You don't need to worry much about having "physically correct" lighting, but there are a few physically correct suggestions on the UE4 forums for values to use for certain wattage lights, the sun, and the skylight for emulating real life. 

You don't really need to play around with all of the lightmass settings and values, the main thing is putting Indirect quality to 4 for your final bake. If you want to just tweak specific things playing with those settings may help, but it's not going to change bad lighting to good lighting. It's follow the scale units in UE4, otherwise the lighting wont behave as it should.

Distance Field AO/GI and Height-fields are really only ideal for outdoor scenes like the Kite Demo or Fortnite.

I was trying to find Koola's scene in market place, I'm not even sure what it's called or what section to look in Is it free or do you have to pay for it?

But yeah, for all intents and purposes, let's assume my target platform is High End PC, and Indoor. I might as well come clean and provide the concept art I am currently working from:


So yeah, this is a scene that would rely HEAVILY on bounced/diffuse lighting. Koola seems to do a really awesome job at that, which is why I referenced his work specifically.  But yeah, my concern isn't so much avoiding seams or anything like that , but just getting that super high end look Koola has.

ZacD

Koola's scene is under Arc Vis, Lightroom: Interior Daylight. I would use a bounce card like from his scene for that light coming from the top on the right door. You could probably use a very dim dark red light from behind the camera to get that fill you see on the top ceiling, and a cool soft blue light floating in the middle of that door opening on the right to add a bit more lighting. Just start playing with it and doing very quick bakes to make sure you are getting the mood right, you don't need to worry about having sharp shadows or avoiding artifacts early on. 

Count Vader

Thanks for the advice, that's pretty helpful. I guess by bounce card you mean those quads he has with a light shining directly at them? I'm still kinda confused as to what exactly those accomplished, is it just like a hack to get the light to diffuse more?

ZacD

Yeah it's just a hack to get the softer lighting, like that desk chair referece picture from your first post, there's probably bounce cards along with that directional light.

Count Vader

Hmm, ok. This is definitely something I'll have to look into more. By the way, do you know why the same effect can't be achieved by just setting a large radius to your light? (That is to say the 'visible radius' where it behaves as if the light were a physical object with limited dimensions instead of a point or an infinite tube or something) LOL I Mean i'm sure if it could be then he would do it that way, I'm just wondering why that is.

Anyways, it seems like this effect can only be done with lights shining through  windows? LIke, it is used to supplement skylight? IE the reflector quad has to be basically floating in space, since if there's too many other objects around it, they can interfere with the light? Like would it make sense for me to do the same reflector technique on the light fixtures that are on the far back wall in my scene, or would that be dumb?

ZacD

I'd mostly use those bounce cards for windows, they mostly make up for the lack of flat directed area lights. I don't think I would ever use them in the middle of a room, they might work for square ceiling lights though.