Dynamic GI : Getting the Most out of LPV ( Light Propagation Volume )

[Datarecovery09]

Thanks for the fast reply! That’s interesting and I actually didn’t know about the .ini thing, but I doubt that it’s causing this issue.
I have both 4.12 and 4.14 installed, so I tried both to convert the test project from 4.12 to 4.14 and to create it completely from scratch. The result was all the same: Black shadows/no GI in 4.14.
Also when I visualize the LPV, the editor shows me that LPV is active.

[Frozenfire]

@anonymous_user_66f7a81309;637172

Thanks for the fast reply! That’s interesting and I actually didn’t know about the .ini thing, but I doubt that it’s causing this issue.
I have both 4.12 and 4.14 installed, so I tried both to convert the test project from 4.12 to 4.14 and to create it completely from scratch. The result was all the same: Black shadows/no GI in 4.14.
Also when I visualize the LPV, the editor shows me that LPV is active.

@Datarecovery09
Active visualize is a sure thing that the ini is correctly configured. All you have to do after that is make sure you are using movable skylight , and movable directional light ( with bUseDynamicIndirectLighting turned on )

[Datarecovery09]

Hi,
Yes I tried adding a skylight - didn’t work. The skylight (movable, static… all the same result) made it look a bit brighter (of course), but that’s no GI and doesn’t come close to the result I’ve got from 4.12.

Here’s a picture of what it looks like right now:

[Frozenfire]

@Datarecovery09;637480

Hi,
Yes I tried adding a skylight - didn’t work. The skylight (movable, static… all the same result) made it look a bit brighter (of course), but that’s no GI and doesn’t come close to the result I’ve got from 4.12.

Here’s a picture of what it looks like right now:

this seems like a very project specific thingy. I have in mind a few other solutions. Maybe you can PM me on UnrealSlackers i’ll help you out on that over that.

[Thunderstruck]

Hi, thanks for this!
It make a big difference for me…
I also noticed that LPV works with process volume both, bound and unbound at least in UE 4.14

[Frozenfire]

@Thunderstruck;637982

Hi, thanks for this!
It make a big difference for me…
I also noticed that LPV works with process volume both, bound and unbound at least in UE 4.14

@Thunderstruck

it works both . but unbound is better because you expect them to be everywhere. bUnbound boolean basically make the effect appears globally instead of only when you’re in the volume

[Datarecovery09]

Hi,

Just a quick update:
My issue is a problem with my UE4.14 installation. Today I had the chance to try it on a different workstation and there it worked perfectly fine. Well, then I have to re-install UE4, it seems.

Nontheless, thanks for your help!

[Rhynedahll]

Hopefully someone might have encountered this issue.

Our LPV works in the editor and in PIE but does not work at all in an independent Client. We checked the consolevariables .ini and it is apparently correct.

Setting the variable in the console also has no effect.

Any suggestions?

[Frozenfire]

@Rhynedahll;639204

Hopefully someone might have encountered this issue.

Our LPV works in the editor and in PIE but does not work at all in an independent Client. We checked the consolevariables .ini and it is apparently correct.

Setting the variable in the console also has no effect.

Any suggestions?

Could the console variable we somehow overwritten? Just to clarify you overwrite the console variable in the ENGINE folder right? ( not the project )

@Rhynedahll

[Rhynedahll]

@Frozenfire;641141

Could the console variable we somehow overwritten? Just to clarify you overwrite the console variable in the ENGINE folder right? ( not the project )

Yes, in the Engine folder of the compiled game.

We have it working in a compiled client now, but the odd thing is that we have had to uncheck Enable and save it that way to get it to work. Seems like an Engine bug at this point or something odd going on in our project.

[mittense]

Yeah, so, LPVs are great. They are wonderful. I love them. But they’re also only really one component of getting GI into a fully-dynamic scene. Distance Field GI (VPL meshes) has gone the way of the dodo. But! Heightfield GI is also fantastic. It does have the brief bake period where it generates color values to approximate the terrain, but other than that there’s no baking involved, and you get some good results from it for not too hefty a render thread price.

But, yeah, LPVs + Heightfield GI + Dynamic Skylight + Dynamic atmospheric directional light. ALL OF THOSE THINGS KIND OF APPROXIMATE A REAL-TIME GI SOLUTION.

(But it’s all pretty manageable for any game targeting a year out).

That’s what I’m using here:

https://cartrdge.com/s/images/unsafe/0x975/filters:no_upscale()/https://cartrdge-east.s3.amazonaws.com/uploads/post/image/4f58d3c6-935c-483a-9b6c-f460e6846003/hr_atmospherics_vol-lighting_plus_truesky.png

[Frozenfire]

@mittense;641290

Yeah, so, LPVs are great. They are wonderful. I love them. But they’re also only really one component of getting GI into a fully-dynamic scene. Distance Field GI (VPL meshes) has gone the way of the dodo. But! Heightfield GI is also fantastic. It does have the brief bake period where it generates color values to approximate the terrain, but other than that there’s no baking involved, and you get some good results from it for not too hefty a render thread price.

But, yeah, LPVs + Heightfield GI + Dynamic Skylight + Dynamic atmospheric directional light. ALL OF THOSE THINGS KIND OF APPROXIMATE A REAL-TIME GI SOLUTION.

(But it’s all pretty manageable for any game targeting a year out).

That’s what I’m using here:

https://cartrdge.com/s/images/unsafe/0x975/filters:no_upscale()/https://cartrdge-east.s3.amazonaws.com/uploads/post/image/4f58d3c6-935c-483a-9b6c-f460e6846003/hr_atmospherics_vol-lighting_plus_truesky.png

Great to see that.
Though I got one question,
Why would you overlap LPV with Heightfield GI? is that how it’s meant to be use?
I thought Heightfield GI was another version of LPV that uses DistanceField to calculate.
I haven’t used Heightfield GI at all though

[Galeon]

@Frozenfire;635389

Hi All,
I decided to write a little guide about getting the mode out of LPV as a Dynamic GI solution. I believe we have achieve a very solid use-case with Dynamic GI and have gained some insight into the usage. With this we would like to give back to the community, there were very little guide on using LPV properly in Unreal Engine 4. I hope this would help someone along the way. Note that this is something I continue expand on as I learn more about LPV , so right now it might be a very long guide.

Your guide is very much appreciated
I use 4.14 and there is no “Affect Dynamic Indirect Lighting” for directionnal lights, also there is no more “Force No Precomputed Lighting” for Lightmass in world settings.
Does LPV works on 4.14 ?

[anonymous_user_6476f099]

I thought I’d give this a go to see how usable it is. Any ideas why I get different results in the viewport from PIE?

Look at this:

But as soon as I click play(PIE) I get this result instead.

I assume this is not normal. This is with 4.14.1.

Here’s my post volume settings.

I have visualised LPV and it’s definitely enabled.

[anonymous_user_6476f099]

@Galeon;642548

Your guide is very much appreciated
I use 4.14 and there is no “Affect Dynamic Indirect Lighting” for directionnal lights, also there is no more “Force No Precomputed Lighting” for Lightmass in world settings.
Does LPV works on 4.14 ?

I just checked and both those options are present in 4.14.1. Your eyes must be skipping over them.

[anonymous_user_6476f099]

Nevermind, I figured out my problem. I had the bias set at 10 for some reason.

[mittense]

@Frozenfire;642527

Great to see that.
Though I got one question,
Why would you overlap LPV with Heightfield GI? is that how it’s meant to be use?
I thought Heightfield GI was another version of LPV that uses DistanceField to calculate.
I haven’t used Heightfield GI at all though

Heightfield GI is astounding, but the lighting only gets applied to static objects. Light Propagation Volumes affect all objects except for translucent materials.

[Galeon]

@xuri;642583

I just checked and both those options are present in 4.14.1. Your eyes must be skipping over them.

http://i.imgur.com/mt4VrWr.jpg

http://i.imgur.com/oSqGQKl.jpg

Thank you Xuri

Must we change materials to work with LPV like that ?

[anonymous_user_6476f099]

@Galeon;642766

Must we change materials to work with LPV like that ?

No. That’s just there for artistic control. It’s optional.

[Teapot_Creation]

Hi Frozenfire,

thanks for your tips, they will be usefull… as soon as I get LPV to work in 4.15.
Did you already tried on 4.15 ? I’ve got the same result with and without LPV activated, and/but can’t add r.LightPropagationVolume = 1 in the .ini file without making the editor crash and unable to launch the project again.