Autodesk 12812-051462-9011 User Guide 3 - Page 1026

TIP In some cases, you might want to set Max. Refractions high and Max. Reflections low. For example, you might have the camera looking through several glasses that are lined up, so they're overlapping from the camera's point of view. In this situation, you might want the light rays to refract twice for each glass (once for each layer), so you'd set Max. Refractions to 2 x [number of glasses]. However, to save rendering time, you could set Max. Reflections to 1, resulting in accurate multi-layer refraction with a relatively fast rendering time. Max. Trace Depth Limits the combination of reflection and refraction. Tracing of a ray stops when the total number of reflections and refractions reaches the Max. Trace Depth. For example, if Max. Trace Depth is set to 3 and the two trace depths are both set to 2, a ray can be reflected twice and refracted once, or vice-versa, but it can't be reflected and refracted four times. Default=6. Enable Reflections When on, mental ray traces reflections. Turn off to improve performance when you don't require reflections. ■ Max. Reflections Sets the number of times a ray can be reflected. At 0, no reflection occurs. At 1, the ray can be reflected once only. At 2, the ray can be reflected twice, and so on. Default=4. These controls are also available on the Rendered Frame Window, as Include In Render > Reflections and Max on page 6081. Enable Refractions When on, mental ray traces refraction. Turn off to improve performance when you don't require refraction. ■ Max. Refractions Sets the number of times a ray can be refracted. At 0, no refraction occurs. At 1, the ray can be refracted once only. At 2, the ray can be refracted twice, and so on. Default=6. These controls are also available on the Rendered Frame Window, as Include In Render > Refractions and Max on page 6081. Subset Pixel Rendering group Render changes to selected objects only When on, rendering the scene applies only to selected objects. Unlike using the Selected on page 6097 option for rendering, however, using this option takes into account all scene elements that affect its appearance. This includes shadows, reflection, direct and indirect lighting, and so on. Also, unlike Selected, which replaces the entire contents of the Rendered Frame Window (except for selected objects) mental ray Renderer | 6281