click on the geometry then select the door from the list
click on the sliding button
then drag to define the door
Then the door will be created:
by openning the door, adjust the open value to 36
then the door will be openned:
select window from geometry 
click on the fixed button
drag to define the window
click on the Quick Render to view the window:
In this example, we got the box, sphere and cylinder.
Hide any object that you want
choose tools>display floater 
Select the sphere and click on 'Selected' 
then the sphere will be hidden
First, create a sphere
then click on the animate button and key in 100
select the sphere and drag to anywhere
then click on the animate button to disable the animation
playback the movie will see the sphere is moving follow the path you move
