# init(path:extrusionDepth:) Creates a shape geometry with the specified path and extrusion depth. ``` 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](https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/CocoaDrawingGuide/Paths/Paths.html#//apple_ref/doc/uid/TP40003290-CH206-BAJIJJGD) in [Cocoa Drawing Guide](https://developer.apple.com/library/archive/documentation/Cocoa/Conceptual/CocoaDrawingGuide/Introduction/Introduction.html#//apple_ref/doc/uid/TP40003290)) 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 in ) 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. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)