The magnification of the top, front, and side views of the model can be changed in several ways. To zoom in by a factor of two, select Navigation|Zoom In or click on the Zoom In button 
. While the cursor is over the model, it will change to a magnification glass with a plus sign in the middle if the magnification can be increased. The user then clicks at the location that is desired to be directly under the cursor after zooming in. Another way to do the same thing is to position the cursor over one of the views of the model and roll the scrollwheel up one click.
To zoom out by a factor of two, select Navigation|Zoom Out or click on the Zoom Out button 
. While the cursor is over the model, it will change to a magnification glass with a minus sign in the middle if the magnification can be decreased. The user then clicks at the location that is desired to be directly under the cursor after zooming out. Another way to do the same thing is to position the cursor over one of the views of the model and roll the scrollwheel down one click.
To zoom in to a specific region select Navigation|Zoom or click on the Zoom button 
. While the cursor is over the model, it will change to a magnification glass if the magnification can be increased. The user clicks down on one corner of the desired region, moves the mouse to the other corner and releases the mouse button. The selected region will be displayed at a higher magnification.
To change the magnification of the 3-D view of the model, hold down the right mouse button. Then click on the 3-D view and move the mouse either up or down. Moving it up will increase the magnification. Moving it down will decrease the magnification.
