How to set up Global Illumination?

Hi everyone,

I am fairly new to the use of the Global Illumination feature (LPV, to be more accurate.). I know that I will need to edit the config file in order to enable the feature and restart the engine. I also I know that I will need to adjust my World Properties accordingly as well. My question is once I have done these things does this kill the need for running LightMass when building my level? Since I am not using Static Light Maps. (To be more clear: Does lighting need to be built with LightMass/Swarm or does it become disabled essentially?)

It just seems too easy to set up. I want to be sure to set it up properly the first time by making sure I am doing this correctly.

Is there anything that I am missing or do I basically understand what I need to do already?


Edit: A new, community-hosted Unreal Engine Wiki - Announcements and Releases - Unreal Engine Forums

If I follow this correctly I’ve essentially answered my own question?

Hi DocRogers,

Here is a simple video I made a while back when someone was having trouble setting it up.

This is the process.

Any other information can be found here in the documentation: Light Propagation Volumes | Unreal Engine Documentation

This is NOT a production ready tool yet. There are going to be some known issues with it, but there are some changes coming from Lionhead Studios that should be implemented in the future to make it better overall.

With regards to Lightmass. It is not “disabled” per se, but it won’t do anything. If you click the build button it will still start swarm agent and finish very quickly since there is no static lighting to be built.

If you’re going to use a fully dynamically lit project, you will want to go into the Settings > World Settings > set Force No Pre-Computed to True. This will disable any static lighting.

I hope this helps.


Hey Tim, I was unable to find Force No Pre-Computed check box. The only thing I’ve been able to find similar to that is under Project Settings and to uncheck Use Static Lighting. Is this the same thing? [Edit.] I found the right setting. It was hidden under the advanced options. So what does the Project Settings one do?

Thanks for clearing up the Swarm thing too. I was curious as to why it would open up and the build would complete instantly. I’m just used to having to build light with LightMass so I thought something was wrong.

I’m not worried about it not being production ready, but I do like the effect. I’m just working on a portfolio piece so I think the risk is worth it in an effort to learn a new tool.

I will check out your other links to help me get going.

Thank you.

Edit: I believe I got it right, but all of my shadows have the “Preview” text all over it. Is this going to show in the Editor and PIE only?

Edit Again: Oh yeah, this is what I want. This works so much better for my large outdoor landscape. Just need to figure out why it’s giving me the preview sampling.