cornerSmoothing

A value that lets you control how "smooth" the corners are. Ranges from 0 to 1.

Signature

cornerSmoothing: number

Remarks

A value of 0 is the default and means that the corner is perfectly circular. A value of 0.6 means the corner matches the iOS 7 "squircle" icon shape. Other values produce various other curves. See this post for the gory details!