To Render a Region

1. Activate the viewport to render, or choose it from the Viewport drop-down list on the Rendered Frame Window.
2. On the Rendered Frame Window, click (Edit Region).

   This automatically sets the Area To Render option to Region, and displays the region window in the Rendered Frame Window and the active viewport. The window has editing handles and a close box (X).

3. To move the region window, drag inside it. To adjust its size, drag the handles.

   To preserve the window's aspect ratio, press and hold Ctrl before you drag a handle.

4. Render the scene.

   3ds Max renders the region only. In Production mode, the Rendered Frame Window is cleared before rendering, but in Iterative mode, the area of the window outside the region remains intact.