Reference Cinema 4D Cinema 4D Prime Mesh Menu Chamfer
Function available in CINEMA 4D Prime, Visualize, Broadcast, Studio & BodyPaint 3D
Chamfer

Options Tool

Options

Flat
Radius [0..+∞m]

Radius defines the radius of the chamfer. If Flat is enabled, the chamfering is linear.

To be more exact:

Flat disabled — each new point has a tangent created to round the chamfer.

Flat enabled — no tangents are created and the spline runs linearly between the two new points.