Multipass Rendering in mental ray for “The Matrix” sequels - Siggraph 2003
- 2. Multipass Rendering in mental ray for “The Matrix” sequels Haarm-Pieter Duiker ESC Entertainment
- 3. Motivation Visual Effects for “The Matrix” sequels • Photo-realism • Integration with live-action • Hundreds of characters / objects on screen in a single frame
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- 7. Rendering Techniques • Light-mapping • Displacement-mapping • Measured-BRDFs • Hair – Shaded / Volumetric Shadowing • Lighting Reconstruction • Universal Capture • Motion Blur • Shadowing from all Light Sources • Interreflection
- 8. Dilemma • Quality compromises were not acceptable. • Impractical / Impossible to Render full scenes. – Memory. – Speed. – Reliability. Ex. The total size of all textures, geometry, and image data used by the Sentinels shot hovered around 100 gigabytes.
- 9. Approach Depth Compositing – Solution • Memory usage reduced by breaking up renders into layers • Speed, reliability, and flexibility benefited by inherent parallelism • Automatic Compositing – Manual approach would be almost impossible • No quality compromises • Simple rendering pipeline
- 10. Approach Depth Compositing – Problem • Edge Artifacts – Pixels values are averages – Depth – Motion Vectors • 2d Motion Blur – Necessary artistic control – Edge Artifacts
- 11. Implementation Multipass Rendering • Access to Sample data before Filtering to Pixels – Depth and Motion Vector Errors eliminated • 2d Motion Blur – Applied to Layers – Edge Artifacts Eliminated for Worst cases
- 12. “The Matrix Reloaded” Need for Multipass • “The Burly Brawl” – Fight sequence with synthetic humans – Use all features of the renderer • “Sentinels Revealed” – Single shot with thousands of objects in frame – Each object modeled and textured at very high resolution
- 13. Thanks Go to • George Borshukov • John Schlag • Dev Mannemela • Ray Haleblian • Scot Shinderman • Andrew Harris • Scott Liedtka • Andy Lomas • Olivier Maury • Kim Libreri