# unproject(_:ontoPlane:) Maps a 2D point from the view’s coordinate system onto the given plane in 3D space. ``` @MainActor @preconcurrency func unproject(_ point: CGPoint, ontoPlane planeTransform: float4x4) -> SIMD3? ``` ## Parameters `point` The point in the view’s coordinate system. `planeTransform` A transform used to define the coordinate system of the plane. The positive y-axis is taken as the normal of the plane. ## Return Value The 3D position in world coordinates, or `nil` if the mapping isn’t possible. --- 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)