Progressive Display (for Nitrous viewports) or adaptive degradation (for legacy viewport drivers) can improve viewport performance when you transform geometry, change the view, or play back an animation. It does so by decreasing the visual fidelity of certain objects temporarily; for example, by drawing larger objects or those closer to the camera as bounding boxes instead of wireframes.
With Nitrous viewports, the controls for display performance are called Progressive Display. In addition to the adaptive degradation features of
earlier drivers, when Progressive Display is on, viewport quality improves incrementally, depending on the availability of
processing time, in a manner similar to the way the Quicksilver hardware renderer improves quality through successive iterations.
When Progressive Display or Adaptive Degradation is turned off, 3ds Max displays full details of the geometry, even if that slows down viewport performance and animation playback. Animation playback might drop frames if the graphics card cannot display the animation in real time.
The Progressive Display / Adaptive Degradation button on the status bar has three states:
Off: No degradation occurs.
On: Degradation can occur under the specified conditions. This is the default setting.
Active: Degradation is being applied currently.
You can change the display options and set other adaptive degradation parameters, on the Viewport Configuration dialog (Customize
menu 
Viewport Configuration Display Performance or Adaptive Degradation panel). Also, you can toggle adaptive degradation for individual objects with the Object Properties Never Degrade setting.
To toggle progressive display / adaptive degradation, do one of the following:
Progressive Display / Adaptive Degradation.
To change the level of progressive display / adaptive degradation in the viewports:
