Chapter 5: mental ray and shaders 6. You can use the 3ds Max Help files to investigate the other settings for Parti Volume, which are generally based on sci- entific information for determining more specific refraction effects; this topic is beyond the scope of this exercise. Close all dialogs and windows and save the file. Keep in mind when using Parti Volume that higher values for most parameters will cause slower render times. Always try to find a compromise between rendering effi- ciency and the look you require for your client. Next, you'll learn about the mr Shader Element shader, which will use information from the rendered image and then output it to a separate file that can be used in compositing software, such as Autodesk combustion. The mr Shader Element will process information generated by Figure 5.40 Changing the Height setting moves the effect up the geometry.