Reference Cinema 4D Cinema 4D Prime Select Menu Main selection tools
Function available in CINEMA 4D Prime, Visualize, Broadcast, Studio & BodyPaint 3D

Lasso Selection

Options Modeling Axis Object Axis Soft Selection

Lasso Selection

Lasso selection behaves like a lasso. Drag to draw a loop around the elements you want to select. As soon as you release the mouse button, the loop is closed automatically.

Tip:
BodyPaint 3D UV Live Selection can be found here.