Lighting From Octane Into Unreal?

We are looking to get a little more quality out of our project, is it safe to say baking all the lighting in octane and bringing into ue4 would be best? Every time I look up baked lighting I only get stuff about lightmass. This is all obviously new to me. I tried it on a couple objects in my scene, but then I don’t get the shadows when I change it to movable. But then when I change the lights to stationary, or movable, I get the red x through them all and it screws up the lighting on the other objects…

I am just trying to figure out the best way to do this for like a walk through type level… Is it possible to do some baking in unreal and some with octane? Or is is more resourceful to do all the baking in unreal and none in octane. What is the best way to go about it to get the true best looking results? I have seen some stuff on youtube that looks really amazing…

Or am I better off baking the entire scene and everything in it? Or is that more to calculate or is lightmass more to calculate after its built?

Can I still have some type of live reflection with a baked object in octane? I usually try all of this but this is a lot to try, I figured I would at least ask to make sure I am not wasting a ton of time baking everything out and having it lag my game. It is VR btw.

Any input on whats the best method to approach for the best results for a walkthrough I am willing to try. Or a tutorial or video or something that can get me started I would appreciate.


Anyone please?

You would need support from the renderer for UE4 to render to the right format/integration with the UE4 lighting system. Basically, the lightmaps are rendered in a certain way and stored in a certain way and it doesn’t offer a way to simply switch those out for ones that you’ve rendered elsewhere.
You probably just need to learn how to use Lightmass, for baked lighting you need to use stationary or static lights, you can use as many static lights as you want but those lights won’t affect any movable objects, so things like characters or animated doors won’t receive lighting from static lights. For stationary lights the direct lighting is fully dynamic and the indirect lighting is baked so it can cast shadows and affect specularity of dynamic objects, the only limitation is that you can only have 4 stationary lights overlapping an area, just make sure to control the light distance and you’ll be fine.

I remember hearing otoy were going to release a plugin for unreal sometime last year but no news it seems. They did do something for unity but i guess unreal is low priority. Maybe we’ll see something this year who knows?

They show off a lot in talks but rarely deliver as i’ve seen all sorts of plans for ray tracing games, vr, lightfields etc for years now and nothing ever really comes of it sadly.

So far, with stuff like Octane and Vray all they do is allow you to render an image within the game engine, they can’t be used for baking lighting although both renderers have said that they could add the feature in the future.

Most likely though, we’ll get GPU raytracing acceleration added for light baking before then.

Luoshang has been working on a GPU Lightmass baker that is still experimental but actually works very well in my limited experience: Luoshuang's GPULightmass - Unreal Engine Forums

It takes some setup, but the results can be pretty great, and a big improvement over regular Lightmass, in my opinion.

What I mean is that we’ll get something that’s accelerated by the GPU raytracing cores

Yeah that stationary light part is whats hurting me. I have a bunch of can lights around the room that are displaying cones. I wouldn’t need shadows though, if I bake all the shadows in to every object from octane and just apply everything in the scene as diffuse. Man thats a lot of work. Would be nice to know if this was a benefit before I started though. I did try the baking from octane, applied to the diffuse and the shadows did look a lot nicer and crisper, but then the floor was a ue4 asset so I lost the shadow on the floor. So I would have to bake the lighting into the floor from octane to get that shadow back, unless I use stationary lights. I think by doing it all in octane I will get a better result, but like I said, that is a lot of work to bake every single object, create a material for every object to apply the bake to and assign it all. And not have a better idea if I will lose performance or not for the VR…

I know what you mean. They do promise a lot and not deliver as much as promised. The engine is still very fast and accurate so you kind of put up with it. People have called them out on their forums plenty of times, but those comments usually get ignored.

Seems above my head at the moment, but something I will keep as a bookmark as I get more advanced in unreal. Thanks

Thanks everyone, I will just have to try to bake a few things and see if I get a performance hit, or upgrade or what not.

If you have a light that’s not casting shadows you can set it as a movable light and turn off the shadows, the performance won’t be super high without the shadows though you still need to control the number of lights.