Drag with middle mouse button pressed to rotate camera.
Drag with Shift+middle mouse button to move camera.
Use mouse wheel to zoom-in/zoom-out.
Use numpad keys 7,1,3 to switch to "Top","Front" or "Side" view.
Use numpad keys 4,6,2,8 to rotate camera.
Click on "Trunk","Branch1" etc label on the right to choose branch group to edit.
(c) Sergey Prokhorchuk 2016, example models created by James Allen, Yorik van Havre, Marco Rochowski (each model contains author and copyright information in meta-info section)