Autodesk 12812-051462-9011 User Guide 3 - Page 1057

Maximum Num. Photons per Sample Sets how many photons are used to shade the volume. Default=100. Maximum Sampling Radius When on, the numeric setting determines the size of photons. When off, mental ray calculates each photon to be one-tenth the size of the scene extents on page 8117. Default: off; value=1.0. The numeric setting is unavailable when the check box is off. Photon Map group These controls tell mental ray how to calculate the photon map for indirect illumination. NOTE If you've specified a photon map here, mental ray continues to use that map instead of generating a new one. To cause the photon map file to be rebuilt, delete the existing file. Read/Write File When on, if the specified photon map (PMAP on page 8093) file does not yet exist, mental ray generates a new map file when rendering. If the specified file does exist, mental ray loads and uses the file. This option becomes available after you click Browse ("...") and provide a name for the PMAP file. ... [browse] Click to display a file selector dialog, which lets you specify a name and path for the photon map (PMAP) file. This automatically turns on Read/Write File. [file name] When you have used the [...] button to specify a photon map file, this field displays its name and path. Delete File Click to delete the current PMAP file. Generate Photon Map Now Processes the photon-mapping pass for all animation frames (as specified in the Common Parameters rollout > Time Output group on page 6124). Generates the photon maps to the specified file without rendering the scene. To reduce flicker when rendering an animation with a networked render farm, use this function first to generate the GI solution for all frames, and then make sure Read/Write File (see preceding) is on before rendering. 6312 | Chapter 20 Rendering