Reference Cinema 4D Basic Features Mesh Menu Extrude Inner
Function available in CINEMA 4D Prime, Visualize, Broadcast, Studio & BodyPaint 3D
Extrude Inner

Options Tool

Options

Maximum Angle [0..180°]

If Preserve Groups is enabled, polygons not exceeding this angle to each other will stay together during the extrude inner. If the polygons exceed this angle, they will be broken apart.

Offset [-∞..+∞m]

Defines the width of the inner extrusion (that is, the distance between an edge of the original polygons and the corresponding edge of the inner extrusion).

Offset Variation [0..+∞%]

Gives a percentage value for the variation of the width of Extrude Inner. This option is only available if Preserve Groups is disabled.

0% - No deviation from the selected Offset value.

60% - All selected polygons are inward extruded between 40% and 100% of the Offset value.

100% - All selected polygons are inward extruded between 0% and 100% of the Offset value.

180% - All selected polygons are extruded between -80% (outward) and 100% (inward) of the Offset value.

Var 0% and 60%.

Subdivision [1..+∞]

Here you can define the number of subdivisions for the inner extrude.

Subdivision set to 0 and 2.

Create N-gons

Enable this option if you have defined subdivisions but want to avoid the additional edges between the original polygons and the inner extrude that this would normally cause.

Preserve Groups

If this option is enabled, the connected polygons will stay together during extrusion, provided they do not exceed the Maximum Angle relative to each other.

Preserve Groups enabled and disabled.

Proceed with caution when inner extruding several connected polygons that you want to keep as a group. In the following example, only the outer edges of the selection are moved inwards. The edges of the inner surfaces of the selection are not affected.
Before and after extruding inwards - only the outside edges will be moved.

This can lead to problems when starting with a certain Offset value, since the outer edges can possibly overlap with the internal ones. The problem occurs when starting with an Offset value that is set too high.

Offset set too high.

To remedy, set Offset to a lower value.