To improve performance when working with the building model, use the Allow navigation during redraw option.
To enable this option, click File tab 
Options, go to the Graphics tab, and select
Allow navigation during redraw.
When the option is enabled (the default):
- You can navigate the model in a 2D view or a 3D view, panning, zooming, and orbiting around the view without waiting for the software to finish drawing model elements at each step. The software interrupts the drawing of model elements in a view, allowing faster and smoother navigation.
When the option is disabled:
- The software completes the redrawing process before allowing you to perform further actions.
- To optimize view navigation, the software suspends certain graphic effects (such as fill patterns and ambient shadows) that affect the display of the model during camera manipulation (pan, orbit, and zoom). When the camera is not being manipulated, the view displays the graphic effects as usual.
When you change this setting, you must close and reopen the model to see the results.