Achieving photorealistic renders in Unreal Engine 5 often means long render times. This guide, presented by TUF, details the essential project settings and Movie Render Queue configurations needed to maximize Path Tracing quality while dramatically boosting rendering speed.
Path Tracing in Unreal Engine 5 is a phenomenal tool for artists seeking unbiased photorealistic results. Unlike traditional real-time rendering, this physically based Monte Carlo renderer meticulously simulates thousands of light bounces to achieve cinematic quality, especially regarding complex reflections and global illumination. However, this precision often comes at the cost of speed.
Fortunately, expert creator TUF (The Unreal Forge) has shared a comprehensive tutorial demonstrating exactly how to optimize settings to get fast, high-quality Path Tracing renders without compromising realism. This guide is critical for anyone looking to push the graphical limits of UE5.
Setting Up Path Tracing for Performance
Path Tracing is built upon Unreal Engine’s ray tracing stack, meaning practical performance necessitates an RTX-class GPU. Before diving into optimization, artists must ensure their project is properly configured.
Initial Project Requirements
To enable this high-fidelity rendering mode, open Project Settings and confirm that both Path Tracing and Support Hardware Ray Tracing are enabled. It is also crucial to verify that SM6 is active under D3D12 shader formats, which typically requires an engine restart.
Once active, you can switch to Path Tracing mode via the Lit mode button in the viewport, which immediately reveals a progress bar tracking the progressive rendering status.
Essential Volume Controls
The core performance controls reside within the Post Process Volume or the Camera settings. Search for “path tracing” in the details panel to access three major performance settings:
1. Max Bounces: Controls the maximum number of light ray bounces per pixel path (default is 32). Lowering this (e.g., to 8 for testing) can speed up initial loading but may compromise realism in complex scenes.
2. Samples Per Pixel (SPP): Dictates the number of rays traced per pixel. This is the single biggest factor affecting image cleanliness and noise reduction. For testing, a lower number like 512 is acceptable, but final renders often require significantly more.
3. Max Path Intensity: Limits path brightness to prevent flickering. Be cautious not to set this too low, as it can dull overall scene lighting.
TUF advises against using the integrated denoiser for Path Tracing, citing potential performance hits and often unsatisfactory visual results, especially for high-quality cinematic exports.
Mastering the Movie Render Queue (MRQ)
For high-resolution, sequence-based output, the Movie Render Queue is indispensable. This powerful tool allows precise control over render quality and includes options for integrating cutting-edge upscaling technology.
Configuring MRQ for Speed and Quality
First, ensure the Movie Render Queue plugin is enabled. If you are using an Nvidia GPU, enabling Movie Render Queue DLSS support is highly recommended, while AMD users should enable FSR. These settings are key to achieving faster, cleaner results.
When setting up the MRQ configuration, remove the default Deferred Rendering and JPG sequence options. Instead, add a PNG sequence (or preferred format) and ensure the following settings are added:
- DLSS: Set this to Quality mode.
- Anti-Aliasing
- Path Tracer preset
The creator notes that while you can keep Game Overrides to ensure cinematic texture quality, it should be removed if you need to exclude UI elements from the final render.
Sample Counts and Warm-Up Frames
Optimizing sample count is critical. The combination of Spatial Sample Count (in the Anti-Aliasing settings) and Temporal Sample Count determines the total samples per frame (Spatial x Temporal).
In the tutorial, the expert achieves excellent results using a Spatial Sample Count of 69 and a Temporal Sample Count of 10, totaling 690 samples per frame. This balance dramatically speeds up the render compared to relying solely on a massive Spatial Sample Count.
To ensure consistent results from the start of your sequence, enable Override Anti-Aliasing and set warm-up frames by enabling Use Camera Cut for Warm Up and Render Warm-Up Frames (the creator recommends 256).
Insight: If DLSS or FSR are unavailable, you must drastically increase the Spatial Sample Count (e.g., to 159 or higher) to compensate for noise, which will inevitably extend the render time significantly (potentially 5 to 6 minutes per frame, based on testing).
Conclusion
Optimizing Path Tracing in Unreal Engine is a delicate balancing act between speed and fidelity. By understanding how to manipulate key settings in the Post Process Volume and leveraging the power of the Movie Render Queue—especially with DLSS/FSR integration—artists can achieve stunning, photorealistic results efficiently. Remember, every scene is unique, so experimenting with your specific sample counts is always necessary to find the perfect balance.
If you want to support TUF’s work or access the specific rendering presets he uses, check out his available resources on Ko-fi.
To continue enhancing your knowledge of game engine production, explore more of our content on Unreal Engine Lighting & Rendering and stay current on the latest features via Unreal Engine Updates & Releases.
Source:
Maximize your Path Tracing Render Quality and speed with these Settings in Unreal Engine 5
