The primary goal for Icarus tree optimization is Foliage Culling and Shadow Stability. Unreal Engine 5 uses a system that handles thousands of individual leaf and branch shadows, which can overwhelm even modern GPUs. This configuration focuses on adjusting the FoliageQuality and ViewDistance to ensure that while the forest remains lush, the engine isn’t over-rendering trees that are miles away, preserving precious VRAM for your immediate surroundings.
Hardware Compatibility & Expectations
- The VRAM Barrier: Icarus is notorious for high VRAM usage. At 1440p or 4K, having 10GB+ VRAM is recommended. These settings help reduce memory “thrashing.”
- SSD Requirement: Because UE5 streams assets constantly, an NVMe SSD is mandatory to prevent the “stuttering” that occurs when moving through dense forests.
- DLSS/FSR/XeSS: For UE5 games like Icarus, using upscaling is almost mandatory. This profile is designed to complement DLSS Quality or FSR Quality modes.
File Location
You can find the Icarus configuration files in the following directory:
%USERPROFILE%\AppData\Local\Icarus\Saved\Config\WindowsNoEditor\GameUserSettings.ini
Technical Configuration (Code Block)
Open the GameUserSettings.ini file and look for the [ScalabilityGroups] section. Adjust the following values to optimize the rendering of trees and dense vegetation:
[/Script/Engine.GameUserSettings]
# Core Display Settings
bUseVSync=False
FullscreenMode=1
FrameRateLimit=0.000000
[ScalabilityGroups]
# Foliage and Tree Performance
sg.ViewDistanceQuality=2 ; 2 (Medium) prevents distant tree pop-in issues
sg.AntiAliasingQuality=3 ; High AA is needed to prevent "leaf shimmering"
sg.ShadowQuality=2 ; Reduces the cost of leaf shadows significantly
sg.PostProcessQuality=2
sg.TextureQuality=3 ; High textures keep bark and leaves crisp
sg.EffectsQuality=2
sg.FoliageQuality=2 ; 2 provides the best density-to-performance ratio
sg.ShadingQuality=2
# Advanced UE5 Overrides (Manually add if missing)
r.Shadow.DistanceScale=1.0
r.Foliage.LODDistanceScale=0.8 ; Slightly brings forward the LOD for faster rendering
r.Tree.DistanceScale=1.0Strategy for Unreal Engine 5 Trees
To ensure the forests of Icarus feel alive without killing your FPS:
- Foliage Quality (The Sweet Spot): Setting
sg.FoliageQuality=2is the ideal compromise. In UE5, “Epic” foliage renders individual blades of grass and leaves at extreme distances. “Medium” (2) maintains the “Deep Forest” look but culls the invisible geometric complexity that you can’t see through the thick canopy anyway. - Shadow Cascades: Trees in Icarus are the primary shadow casters. Setting
sg.ShadowQuality=2lowers the resolution of shadows from distant trees while keeping the ones directly next to your character sharp. This is often the difference between 45 FPS and 60 FPS in the Forest biome. - Anti-Aliasing vs. Shimmering: One of the biggest issues in UE5 forests is “shimmering” on thin branches. Keeping
sg.AntiAliasingQualityat 3 (High) or using DLSS/FSR is essential to stabilize the image, making it easier to spot predators hiding in the brush.
Key Performance Parameters
| Parameter | Recommended Value | Impact |
| sg.FoliageQuality | 2 | Reduces the sheer number of rendered plant actors. |
| sg.ShadowQuality | 2 | Lowers the GPU cost of the dense forest canopy. |
| r.Foliage.LODDistanceScale | 0.8 | Forces lower-detail models earlier for a speed boost. |
| sg.ViewDistanceQuality | 2 | Ensures trees don’t “pop” out of thin air too close. |
Frequently Asked Questions (FAQ)
Why does my frame rate drop when a tree falls?
When a tree is chopped, it becomes a dynamic physics object with its own collision and shadow data. If you experience heavy lag here, lower your EffectsQuality and ShadowQuality in the .ini.
Does “Lumen” affect tree performance?
If you have “Global Illumination” (Lumen) enabled in the in-game settings, it calculates light bouncing off every leaf. For most players, setting ShadingQuality to Medium (2) provides a more stable experience in forest biomes.
How do I fix the “blurriness” in the forest?
This is often caused by DLSS/FSR being set to “Performance.” Switch to “Quality” or “Balanced,” and ensure sg.AntiAliasingQuality is set to 3 in your configuration.
Can I remove the grass entirely to see items better?
While you can lower sg.FoliageQuality, Icarus is designed around its environment. Removing grass completely via .ini is often blocked by the developers to maintain the game’s survival balance (e.g., finding dropped items or small prey).
Conclusion and Expected Results
By manually refining your GameUserSettings.ini to prioritize foliage LOD scaling and shadow resolution, you are mastering the demanding Unreal Engine 5 environment of Icarus. You can expect more stable FPS during storms, smoother transitions between biomes, and a forest that feels dense and immersive without compromising your hardware’s longevity.