In this lesson, you will learn how to define custom scalability presets to ensure your project delivers a consistent experience across diverse hardware, from entry-level PCs to high-end workstations.
The Core Concept: Scalability Tiers
Unreal Engine handles hardware variance through the Scalability system, which groups rendering features into categories like Shadows, Texture, Effects, and PostProcessing. Instead of manually adjusting individual CVars (Console Variables) during gameplay, you define presets (Low, Medium, High, Epic, Cinematic) that act as master switches.
These presets are stored in your project’s Config/BaseScalability.ini (or DefaultScalability.ini). By categorizing your settings, you ensure that low-end hardware disables heavy features like Ray Tracing or complex Volumetric Fog, while high-end machines leverage them to maximize fidelity.
Defining Custom Presets
To implement custom hardware targets, you modify the Scalability.ini files. For instance, to force a specific shadow resolution on Low settings, you define it in the configuration file like this:
[ShadowQuality@0]
r.ShadowQuality=0
r.Shadow.MaxResolution=512
r.Shadow.RadiusThreshold=0.06
[ShadowQuality@3]
r.ShadowQuality=5
r.Shadow.MaxResolution=2048
r.Shadow.RadiusThreshold=0.01
Here, @0 represents the Low preset, and @3 represents High. When a user selects "Low" in your game menu, the engine automatically injects these specific r. console variable values.
Why This Matters
If you have optimized your project using the GPU Visualizer or Unreal Insights, you likely identified which systems (like Lumen or Virtual Texturing) cause the most strain. By assigning these features to the Epic or Cinematic tiers and creating conservative values for the Low tier, you protect the frame rate on weaker GPUs while rewarding players with better hardware.
Always test your presets by toggling them in the Settings > Engine Scalability Settings menu in the Editor. This allows you to observe how your volumetric effects and post-processing stack respond to these shifts in real-time before finalizing your configuration files for deployment.
Key Takeaway: Scalability presets allow you to group complex console variables into defined tiers, ensuring your game maintains performance stability on low-end hardware while enabling premium visual features on high-end systems.