When you are doing complex rotations of the cave, it is sometimes difficult to understand exactly what you are looking at. For this reason, the Viewer has a special 3D Compass that shows the exact angle of rotation of the cave. You can enable the 3D Compass by selecting the "Window->3D Compass" option from the menu bar.
There is also a miniature version of the Tool Bar. It can be manipulated in the same way as the larger Compass and it gives instant access to intuitive 3D rotations. Pressing the button on the right side of the control displays the full-sized 3D Compass.
Compass Directions. The 3D Compass consists of six arms that point north, south, east, west, up and down. Each arm is identified with a letter specifying the direction of the arm. For example, the arm labeled "N" points north.
3D Aspects. To help you see the 3D aspects of the Compass, the arms that are further away are colored blue, while the arms in the foreground are colored red. (Because of the way your eye focuses on red and blue, the blue arms appear further away.) Also, the letters that are in the background are in lowercase while letters in the foreground are uppercase.
Manipulating The Compass. The arms of the Compass can also be dragged with the mouse to set the cave’s rotation. You do this by moving the cursor to some point on the Compass, holding down the left mouse button and moving the cursor.
If you are in Plan View, the Compass can be dragged in a circle to change the Yaw Rotation. If you are in Profile mode, dragging the mouse horizontally across the Compass changes the yaw rotation. Dragging the mouse vertically changes the Pitch Rotation.
Tracking. Depending on the mode you are in, the image of the cave will track in real-time with the position of the 3D Compass. In other words, the cave will change as the Compass changes. In order for the cave to track the Compass changes, the Live Tracking option must be enabled. Also, Hidden Refresh or Plot Mode Refresh must be enabled.