If you have a large model where not all of the geometry is assigned yet but you want to present a preliminary run-through you can filter the 3D view so only assigned resources are visible in the 3D window.

To create a filter for only the assigned resources:
1. Right click in Navigator>3D Filters and select Add
2. Rename the new filter and ensure it is highlighted. Select Activate in selected 3D view (or All 3D views)

3. In the General tab below, check the box to Filter 3D by... Resources

4. Open the Resource tab which appears and right click to select Mark>Assigned Resources. Now only 3D objects assigned to tasks should be showing in the 3D window