Ark: Survival Ascended: Best DefaultEngine.ini for RTX GI Tweaks

The primary goal is to optimize the Screen Probe Gather—the system Lumen uses to sample light—and to adjust the Update Speed so your GPU isn’t overwhelmed by the game’s dynamic day/night cycle and dense foliage shadows.

File Path & Setup

1. Navigate to: [Ark Install Path]\ShooterGame\Saved\Config\Windows\Engine.ini
2. Open with: Notepad++ or a similar text editor.
3. Pro Tip: If you are using an RTX 40 or 50 series card, ensure you have Frame Generation active in-game. Our config specifically optimizes the underlying latency that Frame Gen can sometimes amplify.

Optimized “Lumen-Focus” Configuration Table

Parameter	Recommended Value	Technical Purpose
r.Lumen.HardwareRayTracing	0 (Software)	The Stability Fix. Prevents crashes on 8GB-12GB VRAM cards.
r.Lumen.SceneLighting.UpdateSpeed	2	Slows down lighting updates to reclaim ~10% GPU overhead.
r.Lumen.ScreenProbeGather.MaxRayIntensity	1.0	Eliminates “Light Leaks” and blinding white flashes in caves.
r.Lumen.Reflections.Allow	0	Disables Lumen reflections to save massive FPS while keeping GI active.
r.Nanite.MaxPixelsPerEdge	4	Optimizes Nanite meshes to reduce the geometry load on the GI solver.

[SystemSettings]
r.Lumen.HardwareRayTracing=0
r.Lumen.DiffuseIndirect.Allow=1
r.Lumen.Reflections.Allow=0
r.Lumen.SceneLighting.UpdateSpeed=2
r.Lumen.ScreenProbeGather.MaxRayIntensity=1.0
r.Lumen.ScreenProbeGather.ScreenTraces.HZBTraversal=0
r.Lumen.ScreenProbeGather.Temporal.DistanceThreshold=0.2
r.Nanite.MaxPixelsPerEdge=4
r.VolumetricCloud=0
r.VolumetricFog=0

HowTo: Engineering the Ultimate ASA Lighting Balance

Follow these GameEngineer.net technical steps to achieve a stable 60+ FPS experience:

1. The Software Lumen Secret: Even on high-end RTX cards, ASA’s implementation of Hardware Ray Tracing can be unstable. By setting r.Lumen.HardwareRayTracing=0, you switch to Software Lumen. This still looks incredible but uses the GPU’s shaders more efficiently, often resulting in a more consistent frame time ($T_{frame}$).
2. Stopping the “Cave Flicker”: If caves look washed out or flicker wildly, the MaxRayIntensity is the culprit. We’ve set it to 1.0 to normalize the light bounces. If the scene still looks too dark, you can increase this to 2.0.
3. Update Speed Optimization: The world of Ark is constantly moving. By setting r.Lumen.SceneLighting.UpdateSpeed=2, the engine takes slightly longer to “settle” the lighting when the sun moves. This is nearly invisible to the eye but prevents the GPU from spiking every few seconds.
4. The Reflection Trade-off: Global Illumination is what makes Ark look “next-gen,” but Lumen Reflections are the “FPS Killer.” Keeping r.Lumen.Reflections.Allow=0 keeps the beautiful bounced light on the ground and trees while saving enough power to run at higher resolutions.
5. Volumetric Removal: For pure performance, we’ve included r.VolumetricCloud=0 and r.VolumetricFog=0. These are the two heaviest visual features. If you must have them for immersion, change them to 1, but expect a 20-30 FPS drop.

Technical Explanation: Screen Probe Gather ($SPG$)

In Ark: Survival Ascended, Lumen uses a technique called Screen Probe Gather. The engine places “probes” across your screen to sample the surrounding light and color ($C_{light}$).

By adjusting the Temporal.DistanceThreshold, we are telling the engine how much a probe can move before it has to be completely recalculated. A value of 0.2 provides a “tight” threshold that reduces ghosting on moving dinosaurs while maintaining a high Light Cache Hit Rate. This ensures that the global illumination stays grounded and responsive without the “shimmering” effect that plagues many default UE5 configurations.