In this lesson, you will learn how to lock in your Lumen lighting consistency by applying final quality overrides and console variables to ensure your visual targets remain stable across different hardware configurations.
As you move from development to production, relying solely on the Project Settings menu is often insufficient. To guarantee that Lumen behaves identically on a developer’s high-end workstation and your target consumer hardware, you must leverage Console Variables (CVar). These variables act as the final authority, overriding dynamic scalability settings that might otherwise degrade your lighting quality during gameplay.
Defining Your Quality Baseline
When finalizing, you should create a DefaultScalability.ini file in your project’s Config folder. This ensures your intended Lumen settings are enforced the moment the game launches. For instance, if you have meticulously tuned your Lumen Scene Quality and Final Gather settings, you want to prevent the engine's automated scalability system from dropping these values if it detects a frame-rate dip.
You can force high-fidelity settings by adding these commands:
[ScalabilitySettings]
r.Lumen.DiffuseIndirect.Allow=1
r.Lumen.Reflections.Allow=1
r.Lumen.DiffuseIndirect.Quality=4
r.Lumen.Reflections.MaxRoughnessToTrace=1.0
r.Lumen.Scene.FullPrecision=1
Ensuring Consistency
By explicitly setting r.Lumen.DiffuseIndirect.Quality to 4 (or your validated production value), you eliminate the variability of the "Epic" vs. "Cinematic" scalability presets. This is critical for production because it guarantees that the light bounces, occlusion, and reflection stability you saw in the editor are exactly what the player experiences.
Furthermore, verify your Hardware Ray Tracing (HWRT) state for production. If your project depends on HWRT for lighting accuracy, ensure r.DynamicGlobalIlluminationMethod=1 and r.ReflectionMethod=1 are locked in your configuration. This prevents the engine from falling back to Software Ray Tracing (SWRT) on compatible systems, which would cause a noticeable shift in light bounce accuracy and contact shadow fidelity.
Always test these overrides on your target minimum-spec hardware; while forcing high quality ensures visual consistency, it shifts the responsibility of performance optimization entirely onto your mesh density and scene complexity management.
Key Takeaway: Use project-level console variable overrides in your DefaultScalability.ini to bypass dynamic scalability and enforce a locked, consistent Lumen quality baseline for your final shipping build.