3D Renderer Controls

Toolbar - Buttons toggle between Select Mode and Camera Mode.
Shift - Hold to force Select Mode.
Alt - Hold to force Camera Mode.

Select Mode
Left Click - Select Node or Edge
Left Click and Drag - Selection box
Ctrl + Left Click - Add to current selection
Right Click - Context menu

Camera Mode
Click and Drag (Near Center) - Orbit Camera
Click and Drag (Around Perimeter) - Roll Camera
Mouse Wheel - Zoom In/Out

Keyboard Controls
Up, Down, Left, Right - Orbit camera (at constant speed)
R - Reset camera to default position