Autodesk 12812-051462-9011 User Guide 3 - Page 1024

rendering is used for direct illumination ("primary rays") only; ray tracing is used for indirect illumination (caustics and global illumination) as well as reflections, refractions, and lens effects. You can disable one or the other option, but not both. For example, if only ray tracing is enabled and you turn it off, 3ds Max enables scanline rendering. Scanline group Enable When on, the renderer can use scanline rendering. When off, the renderer uses the ray-tracing method only. Scanline rendering is faster than ray tracing, but cannot generate reflections, refractions, shadows, depth of field, or indirect lighting. Default=on. Use Fast Rasterizer (Rapid Motion Blur) When on, uses a fast rasterizer method to generate the first generation of rays to trace. This can improve rendering speed. Default=off. This option works well with object motion blur, and also with scenes that have no motion blur. The following settings are available for the fast rasterizer: ■ Samples per Pixel Controls the number of samples per pixel used by the fast rasterizer method. More samples result in greater smoothness, at a cost of render time. Range=1 to 225. Default=16. ■ Shades per Pixel Controls the approximate number of shading calls per pixel. Greater values result in more accurate renderings, at a cost of render time. Range=0.1 to 10000 (ten thousand). Default=2.0. NOTE mental ray provides a Time Samples setting specifically for motion blur in the fast rasterizer. When Use Fast Rasterizer is on, the Camera Effects rollout >Time Samples on page 6287 label changes to Time Samples (Fast Rasterizer) to indicate that this version of Time Samples is now in effect. Ray Tracing group Enable When on, mental ray uses ray tracing to render reflections, refractions, lens effects (motion blur and depth of field), and indirect lighting (caustics and global illumination). When off, the renderer uses the scanline method only. Ray tracing is slower but more accurate and more realistic. Default=on. To render reflections, refractions, depth of field, and indirect lighting (caustics and global illumination), Ray Tracing must be enabled. mental ray Renderer | 6279