Inset Straight Skeleton

You can either inset a single polygon or you can treat groups of polygons connected together as a single region, forming a complicated polygon (that may include holes) to be insetted as a unit.

In addition to insetting, it is often useful to raise or lower the inset polygon (perpendicular to the inset plane), so a parameter to do that is included also.

Click Mesh then Inset Straight Skeleton to enable the script.

Enter mesh Edit Mode on a mesh object, and select one or more faces.

缩放

量

The distance to move the edges inward.

The distance to move the inset polygons upward.

整体

If checked, treat all selected faces as a region to be inset, otherwise inset each face individually.

Quadrangulate

Todo.

The method used is described on the Wikipedia page. Consider this starting polygonal region:

As the edges move inward at a constant speed, two kinds of events can happen. One is that an advancing corner can hit an advancing edge, as seen on the right part of this picture:

When this happens, the inset polygon splits into two.

The other is that an advancing edge can shrink to a point. When the whole process continues until the end, you get something like this:

One cool thing about this algorithm is that if you move upwards or downwards (perpendicular to the inset plane) at a constant speed, you form ‘roofs’ with a fixed pitch.