Performance
Performance Considerations
Section titled “Performance Considerations”Rendering lens flares is a GPU-intensive process that requires a significant amount of VRAM for textures, ray data, and intermediate buffers. Complex lens systems, high render quality, and spectral effects can quickly increase memory usage and render time.
In many cases, a lens system can be optimized without any visible loss in quality by making targeted adjustments.
Reducing Render Quality and Wavelength Count
Section titled “Reducing Render Quality and Wavelength Count”Two of the most impactful performance controls are Render Quality and Wavelength Count.
- Render Quality controls ray density and scales quadratically
- Wavelength Count controls spectral sampling and affects dispersion smoothness
To optimize performance:
- Lower render quality gradually until artifacts become just barely noticeable
- Reduce wavelength count to the lowest value that still produces smooth dispersion
Small reductions in these values can result in large performance and VRAM savings, often with no perceptible visual difference.
Sorting and Limiting Ghosts
Section titled “Sorting and Limiting Ghosts”Lens systems can generate a large number of ghosts, many of which contribute very little to the final image.
Ghosts are also relatively expensive to render, so reducing their count can significantly improve performance.
To optimize ghost rendering:
- Use Sort Ghosts by Intensity
- Identify the brightest and most visible ghosts
- Render only the first few ghosts that meaningfully affect the image
In most shots, a small subset of ghosts accounts for the majority of the visual impact.
Practical Optimization Strategy
Section titled “Practical Optimization Strategy”A typical optimization workflow:
- Start with your desired look at full quality
- Lower render quality and wavelength count incrementally
- Sort ghosts by intensity
- Limit ghost rendering to only the visible contributors
- Verify that the final result remains visually unchanged
This approach minimizes VRAM usage while preserving the intended appearance.
Summary
Section titled “Summary”- Lens flare rendering is VRAM-heavy
- Render quality and wavelength count are primary performance drivers
- Ghost count has a major impact on render cost
- Sorting and limiting ghosts is an effective optimization
- Careful tuning can preserve visual fidelity while improving performance
By optimizing these key parameters, complex lens systems can be rendered efficiently even under tight memory constraints.