The outline to offset.
How far the outline moves, in model units: positive grows outer contours and shrinks holes, negative does the opposite.
How corners are treated: round, square, miter or bevel.
For miter joins, how far a corner may reach as a multiple of delta before it is squared
off; 2 is the smallest allowed.
For round joins, how many segments a full circle of rounding gets.
A cross-section and the offset settings for
crossSection.operations.offset.