Viewer

2D Navigation

Action	Shortcut/gesture
Pan	Alt + left drag
Zoom	Alt + right drag, or mouse wheel
Toggle red channel	R
Toggle green channel	G
Toggle blue channel	B
Toggle alpha channel	A

3D Navigation

Action	Shortcut/gesture
Tumble	Alt + left drag
Track	Alt + middle drag
Dolly	Alt + right drag, or mouse wheel
Expand selection	Down arrow
Fully expand selection	Shift + down arrow
Collapse selection	Up arrow