Autodesk 12812-051462-9011 User Guide 3 - Page 1045

Rays per FG Point Sets how many rays are used to compute indirect illumination in a final gather. Increasing this value makes global illumination less noisy, but also increases rendering time. Default=250. Interpolate Over Num. FG Points Controls the number of final gather points that are used for an image sample. It is useful for solving noise problems and getting smoother results. For each final gather point, mental ray interpolates (averages) indirect light values over the nearest N final gather points, with N specified by the value of this parameter, as opposed to points within the specified radii as with the alternate method on page 6305. Increasing the value increases the smoothness of the result, and the required number of calculations, hence the render time (but not as much as you might expect). This setting is unavailable when Use Radius Interpolation Method on page 6305 is enabled. Diffuse Bounces Sets the number of times mental ray calculates diffuse light bounces for each diffuse ray. Default=0. Like Maximum Reflections and Maximum Refractions, this value is subject to the restriction of Max Depth. If you set Diffuse Bounces higher than Max Depth, the latter setting is automatically raised to the Diffuse Bounces value in the MI output file, but this is not reflected in the 3ds Max interface. This setting is also available on the Rendered Frame Window, as Bounces on page ?. NOTE When Global Illumination on page 6310 is on, changing this setting has no effect. Weight Controls the relative contribution of the diffuse bounces to the final gather solution. The value scales from "using no diffuse bounces" (value=0.0) to "use full diffuse bounces" (value=1.0). Default=1.0. Final Gather Map group These controls tell mental ray how to calculate the final gather map for indirect illumination. The map uses the FGM file format on page 7971. Read/Write File When on, the mental ray renderer saves the final gather map to the specified FGM file, if it doesn't already exist. If the file exists, mental ray loads it and uses the map data it contains instead of generating a new one. This setting is available on the Rendered Frame Window as Reuse > Final Gather on page 6083. 6300 | Chapter 20 Rendering