Progressive rendering in mental ray

Progressive rendering begins with a lower sampling rate and then progressively refines the number of samples towards the final result. Progressive rendering is most ideal for use with IPR rendering.

To enable progressive rendering, do one of the following:

• In the Render View window, enable IPR > IPR Quality > IPR Progressive Mode.
• In the Quality tab of the Render Settings window, under the Sampling section, set Progressive Mode to IPR Only.