How to enable Light Propagation Volumes GI [ WIP AND BETA]

I’ve been able to use it with pointlights, but it’s kinda weird though.

Cannot wait until Epic Games implements LPV officially ! This is going to be breaking news :slight_smile:

Right now fully real-time lighting and translucent screen space reflections are the only thing really missing from UE4, can’t wait until they’re fully implemented.

Kinda feeling like I’m ressurecting this thread from the dead, but it seems appropriate.
I’m running 4.3.0 and for the life of me I cannot get LPV to work. I modified the ini file, i tried it in an empty level, in the default level and the cornell box that was linked in the wiki entry for LPV setup and nothing is working. I’m thinking now there’s something weird with my compile of 4.3 since I can’t find a single user that had any issue with it ( read a lot about crashes - but not about implementation just flat out not working.)

have you followed the instructions on the wiki? There is a bit more to do than just the ini setting. For instance you need to disable Lightmass and you need to turn on "Affect Dynamic Indirect Lighting" on your "Directional Light"

See here for detailed instructions:

Like I stated in my post, I followed all the instructions ( added the r.LightPropagationVolume=1 in the console variable ini file
Set force no precomputed lighting on.
Set a directional light ( only light in level just in case - although the cornellbox example also has a skylight present) and it is affected dynamic indirect light.
I also added a post process volume to check if maybe the GI boost was so miniscule I couldnt see it, but tweaking all those values turned out to accomplish nothing as well.

If it was just me forgetting to disable lightmas, or turning off affect dynamic light, it would be a quick fix, but that’s not it. Plus, if I’m opening up the cornellbox map scene that is linked at the bottom of the wiki entry and out of the blue it’s not working ( even though all the settings on there are correctly checked) I’m thinking there’s an issue with my compile of 4.3. Can’t really ugprade to 4.4 at the moment, so I guess I’ll go compile it from source and try it again.

Edit: Just in case someone mentions it, my card supports shader model 5.0 . So that’s not it either.

This only shows how advanced Cryengine is, they’ve got this tech for years
2014 and UE4 is not yet ready to have GI

I agree, Epic should propose at least a similar realtine GI solution.

First of all the Cryengines uses LPV as their Realtime GI solution which just supports sunlight. As next, the UE4 offers much more control over the LPV than the Cryengine does. And last but not least, developing features like that take time and where often build upon the work of others. One comes up with a technique another refines it until WE have a acceptable solution. Sorry if i sound a bit angry but this constant engine war ******** is annoying as ****. This kind of competition blocks progress instead of encouraging it.

CryEngine uses SVOGI, multiple bounces.

Yep now i know you’ve corrected me in the other thread. Sorry for my mistake, but still except the LPV statement the rest of it stays the same.

I just started messing with the VXGI UE4 build and i have to say it’s very promising, the results are better than pre-baked lightmass and better that what i have seen in CryEngine.

I don’t think it will be a viable real-world solution until DX12 is commonplace but - I do agree that UE4 should have had it’s own native real-time GI implemented by now especially since it was demonstrated with real-time GI before the engine was released and it was a let down when it was released without it.

Are you sure it looks better than lightmass? I doubt it, 2-3 bounces vs 100 bounces of G.I is quite a difference. I don’t think you can get complex shadows with VXGI.

For what it is worth, the default lightmass setting is only 3 bounces and you can get pretty good results with that.

And coming from the arch-viz side, before we had tech that allowed 100+ bounces, 6ish sufficed. Don’t forget the inverse square law. Everyone can spot the difference between 2 and 3 bounces, but I defy anyone to do the same for 99 and 100.

Can LPV enable fully dynamic objects (like a player character or a moving animated enemy) to emit light that will bounce 3-6 times off other fully dynamic objects? Can VXGI do that?

Hi, what’s the state of LPV ? when UE will LPV with cone lights ?

The company that started with the LPV is now closed, not sure if Epic will end this or not tbh.

2 years in 2016, and no a real realtime GI solution in Unreal Engine 4, is not a real problem but would be nice have something.

It is sad that both Fable Legends and Lionhead studio are closed. Lionhead studio was the one who integrated LPV into UE 4 and continued improving it. In UE 4.10, LPV works a lot better than in 4.0. It provides more adjustable features and less light leaking. I am on an exterior ArchViz project and LPV suits it best since Nvidia’s VXGI costs about 40fps and I cannot afford that on a large exterior scene. With LPV and HBAO+, almost none lighting artifacts happen, and there is not a big impact on performance either. Well, I guess probably LPV is a good way to go.


Cryengine SVOGI

Cryengine has nice result in indoor scene but ue4 lpv is … :mad: