1. To reposition the avatar in the scene, press and hold the Ctrl button, click and hold the left mouse button, and move the mouse around. Alternatively, use the hotkeys Ctrl + left arrow, right arrow, up arrow, down arrow move the avatar left, right, up, and down, respectively.

2. To rotate the avatar, press and hold the Ctrl button, click and hold the right mouse button and move the mouse left or right.  Alternatively, use the hotkeys 'Ctrl + A', and 'Ctrl + D' to rotate the avatar left and right, respectively.

3. To zoom the avatar, scroll the mouse wheel, or use the hotkeys Ctrl + and Ctrl -.