If no mouse button is pressed:
Mouse wheel forward / backward |
: Zoom out / zoom in |
If the left mouse button is pressed:
Mouse to right / left |
: Turn right / left |
Mouse up / down |
: Turn to top / bottom |
If the right mouse button is pressed:
Mouse to right / left |
: Shift to right / left |
Mouse up / down Mouse wheel forward / backward |
: Shift to rear / front : Shift to bottom / top |
If the 
- key and the left mouse button are pressed:
Mouse up / down |
: Zoom out / Zoom in |
If the 
- key and the right mouse button are pressed:
Mouse up / down |
: Shift up / down |
By view|default position the machine comes in view again.
To head for a point in the machine that is interesting for you in an optimum way you act like this:
- look directly from above on the machine by moving the mouse toward you with pressed left key
- move the element with the right mouse button into the middle (where the small square flashes from time to time)
- look horizontally over the machine by pushing away the mouse with pressed left key
- move the machine with right mouse button pushed and scrolling wheel up/down until the element of your interest is in the middle
- now you find the best view by zoom and turns
You can shift the element marked in a 2-D view quickly into the middle by selecting 'focus', symbol: 
.