3D scene navigation

There are several commands available in the 3D View to move the 3D scene and see the objects from any angle and from any distance.  

Zoom In and Zoom Out: Use the right mouse button in the 3D View to zoom in and zoom out the entire 3D scene. To zoom in, right click on the top part of the 3D View and to zoom out, right click on the bottom. Keep the right button pressed to keep moving the scene. The further the mouse position from the center of the 3D View is, the faster the scene moves. The keyboard can also be used: press Ctrl + Shift + Up Arrow  to zoom in, and Ctrl + Shift + Down Arrow to zoom out. The same commands are available from the Toolbar by clicking  and .

Rotation: Left click on the 3D View to rotate the entire 3D scene. The axis of rotation passes through the center of the 3D View and the scene rotates in the direction given by the the position where you clicked the mouse. Keep the mouse button pressed to keep the scene rotating and move it to change the direction. The further the mouse position from the center of the 3D View is, the faster the scene moves. The keyboard can also be used: press Ctrl + Arrow  Key to rotate in the direction of the arrow key. The same commands are available from Toolbar by clicking .

Translation: Use the middle mouse button in the 3D View to translate the entire 3D scene. The direction of the movement is given by the segment from the center of the 3D View to the position where the middle button of the mouse is clicked. Thus, to translate the scene to the bottom right, place the mouse at the bottom right corner of the 3D View. Keep the middle button pressed to keep the scene moving. The further the mouse position from the center of the 3D View is, the faster the scene moves. Use the arrow keys to translate using the keyboard. The same commands are available from the Toolbar by clicking .

Center the scene: Use the button  from the Toolbar to center and zoom the scene in order to visualize all the objects. Alternatively, the key R can be used to perform the same operation. 

Note: Make sure the 3D View is active to use the keyboard for 3D navigation. If the keys do not respond, click on the 3D view to activate them.