init(path:extrusionDepth:)

Declaration

convenience init(path: UIBezierPath?, extrusionDepth: CGFloat)

convenience init(path: NSBezierPath?, extrusionDepth: CGFloat)

Parameters

• path:

  The two-dimensional path forming the basis of the shape.

• extrusionDepth:

  The thickness of the extruded shape along the z-axis.

Return Value

A shape geometry.

Discussion

SceneKit determines the filled area of the path using the even-odd winding rule (see Winding Rules in Cocoa Drawing Guide) and extrudes this area to create a three-dimensional geometry. The result of extruding a self-intersecting path is undefined.

The extruded shape is centered at the zero point of its z-axis. For example, an extrusion depth of 1.0 creates a shape that extends from -0.5 to 0.5 along the z-axis. An extrusion depth of zero creates a flat, one-sided shape.

The path’s flatness (see flatness in NSBezierPath) determines the level of detail SceneKit uses in building a three-dimensional shape from the path. A larger flatness value results in fewer polygons to render, increasing performance, and a smaller flatness value increases the smoothness of curves at a cost to performance.