I’m currently working on a small project in Unreal Engine 5, and I’ve been experimenting with different lighting setups. My goal is to get a good balance between visual quality and performance, especially for mid-range Mobile and PC hardware in 2025.
Right now, I’m using Lumen for global illumination, a mix of dynamic and static lights, and virtual shadow maps. The results look great, but the frame rate takes a noticeable hit in certain areas of the map.
I’d like to ask:
What’s your go-to approach for optimizing lighting without losing too much quality?
Are there specific UE5 settings or console commands that help maintain stable performance?
Would switching some lights to baked lighting make a big difference in performance?
Any tips, workflows, or resources would be greatly appreciated. I’m aiming for the latest version of Unreal Engine to look good but still run smoothly on Android and desktop platforms.
The first, best practice is to verify your lighting solution will actually work with the hardware you’re targeting. Lumen has almost no mobile support. The only devices it works on are high-end Androids that employ Vulkan SM5, and even that support is still in the experimental stage.
Next, if you’re hitting performance snags, you’d need to profile your performance with Unreal Insights to pinpoint your congestion. Couple that with familiarizing yourself with console commands like stat unit/stat gpu to get timings in realtime. Lumen is almost certainly contributing a lot to your performance woes, it’s not cheap. But to be honest, it’s probably way too early for performance profiling to give you meaningful context as it relates to your final vision.
There are no magic switches to boost performance. You’ll need to research the performance implications of everything you’re using so you can effectively assess what you can afford with your performance budget. Nothing is free. E.g. shadows aren’t cheap, especially distance field shadows. Disable shadows entirely for lights that aren’t adding meaningful substance to a scene. Dynamic lights aren’t cheap either. Multiple dynamic lights affecting a single object increase shader complexity and gpu load quickly. You’ll also want to rely on things like lighting channels to avoid unnecessary calculations.
Other stuff is going to come at a cost too, beyond lighting. Post-process effects like temporal anti-aliasing aren’t free either. Ultimately, it’s about prioritizing what truly matters. Start with cheaper alternatives (static lights over stationary/dynamic ones, FXAA over TAA, etc. etc.), and only upgrade to a more expensive alternative where it adds meaningful substance to a scene. Even then, you’ll probably need to compromise later on down the road once you’re able to profile in a meaningful way.