The Lightspeed Automatic Interactive Lighting Preview System

An automatically-generated preview at 914x389 resolution with 13x13 supersampling for a scene featuring 42 spot, environment, and message-passing lights and multiple 20k instruction surface shaders. The upper-left half of the image is rendered with our approach while the lower right is the final RenderMan frame – the seam is barely visible. The error heat map is in percentage of maximum 8-bit pixel value and is mostly due to shadow map artifacts. This scene renders interactively at 4x4 subsampled resolution at 9.2 Hz, while refining to the above antialiased final-quality in 2.7 seconds, compared to 57 minutes in RenderMan. We present an automated approach for high-quality preview of feature-film rendering during lighting design. Similar to previous work, we use a deep-framebuffer shaded on the GPU to achieve interactive performance. Our first contribution is to generate the deep-framebuffer and corresponding shaders automatically through data-flow analysis and compilation of the original scene. Cache compression reduces automatically-generated deep-framebuffers to reasonable size for complex production scenes and shaders. We also propose a new structure, the indirect framebuffer, that decouples shading samples from final pixels and allows a deep-framebuffer to handle antialiasing, motion blur and transparency efficiently. Progressive refinement enables fast feedback at coarser resolution. We demonstrate our approach in real-world production