Press on the coloured cubes faces to build onto that cube.
Click Undo to detroy the last placed cube.
The Second button selects the Mode of the visualization of the cubes:
Fixed disables all interactions with the cube.
Move mode allows the user to move the camera away and towards the cubes (W -> Up, S -> Down)
Look mode allows the uer to look around their camera position (WASD keys)
Rotation mode allows the user to rotate the shape along the x and y axis (WASD)
Presentation mode colors the coloured block in the texture and disables the ability to build and disables the ability to accidentaly Undo build