What's the plan for giant open world games if....

Development Rendering
1

What is Epic’s plan for giant open world games if you have to bake in lighting?

If you have a something even as small as a 4k map, wouldn’t it be next to impossible to bake in all the lights and wouldn’t the lightmap texture memory get too large?

I’m aware of the LPV system that you can enable, however, I’ve read that Epic isn’t moving forward with that solution…

2

Every big game has to deal with that problem, most of the time they use dynamic lighting. The engine can manage the lightmaps, but it would still take a huge amount of storage space, plus you’d need a lot of RAM to be able to build the lighting.
There’s a few things that can be improved with LPV but it’s pretty much finished.

3

Give LPV a go, it isnt as bad as you might think. With increased scale it handles distant views as well and you can disable or resize it with post process volumes for interior sections of the game where GI bleed would be obvious.

4

I ported my (VR) game to 4.5 to check out LPV along with the distance field shadows… it’s pretty awesome. I figured it would tank performance but it’s actually quite good, even in VR, with a bunch of lights casting shadows too.

5

Yeah, there is also DFAO to support LPV. I still havent been able to use it though, it keeps crashing on me and they didnt know the reason the last time Daniel Wright mentioned it. :\ Hopefully it will be magically fixed with the official release of 4.5.

6

DFAO didn’t work for me in the Rift (just doesn’t show up) from what I could tell.

7

What’s DFAO and how do you activate it?

8

Distance Field Ambient Occlusion(DFAO)

9

Also see here for setting up LPV GI - A new, community-hosted Unreal Engine Wiki - Announcements - Epic Developer Community Forums

10

Thanks for all the info guys.

So, I got it working and it runs fine on my machine (around 40-50fps a second).

I built my machine last year, I’m running an AMD Radeon HD 7900 series. Nothing too beefy.

I keep hearing how LPV is slow and buggy, it looks and runs fine to me??

Is something that Epic plans to move forward with in the upcoming releases? Or will it be baking lights instead?

11

It is slow compared to static lighting, but for a large and open map when you consider the things darthviper mentioned it may be worth it depending on your project.

There is only one bug that i know of and there is a workaround for it which you can see here. Other than that it just has limitations like not enough volume resolution for thin walls which can cause GI bleeding. Also check out Daedalus’s posts in thread to improve LPV lit environments even more.

12

LPV is the low end of the dynamic GI solutions so it’s not as slow as the more comprehensive systems. As far as development goes, there’s not all that much more to be done to improve it, other systems will be much better depending on what they eventually decide to integrate into the engine.

13

Is it possible that someone could make a plugin for better realtime GI and sell it on the market place? I think I’ve heard about the Unity store having something like that…

Or is UE4 more “closed” for that kind of thing?

14

People can do that, and there’s someone in the WIP section working on something though I don’t know if their approach will end up working out, but it’s definitely possible. I think it’s likely Epic will add a better solution in the next few years, but if not I’d hope for maybe Nvidia to release their VXGI integration.

15

You have full access to the source code for a reason. No reason why you can’t develop your own plugin for if you think you can. As far as I’m aware, at least one person is working on one, in addition to Nvidia working on VXGI for the UE4.

16

Good to know :). I’m coming from the Cryengine so I’m accustomed to having my hands tied when it comes to source code and what not…

About VXGI, will that be exclusive to just Nvidia. Kinda like Mantle is with ATI? (I’d hate to see the PC industry divide itself like that…)

17

More info on VXGI here: Looks like VXGI and Apollo 11 Demo Is Coming Officially To UE4 - Community & Industry Discussion - Epic Developer Community Forums

Apparently it isnt limited to Nvidia hardware but it still needs work. Somewhere in that video they say that Apollo 11 demo is running at around 40FPS on that GTX 980 which is supposedly optimized for VXGI, so…