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

Extrude Object

Basic Coord. Object Caps

Extrude Object

The Extrude object extrudes a spline to create an object with depth. The extruded object appears as soon as you drop the spline into the Extrude object in the Object Manager.

You can also use splines to cut out holes. If, for example, a single spline object has two segments (an outer circle and an inner circle), the inner circle will be interpreted as a hole. Cinema 4D detects hole splines automatically.

All segments must be contained within a single spline object — additional splines will be ignored. To connect the splines, select them and choose Mesh / Conversion / / Connect Objects.
Before extrusion …
… and after extrusion

Note also the Spline Mask, which can be used to combine (join, break, etc.) splines (Primitives in particular), which makes a comprehensive parametric workflow possible.