# unproject(_:ontoPlane:relativeToCamera:) Unproject a 2D point from the view onto a plane in 3D world coordinates. ``` @MainActor @preconcurrency func unproject(_ point: CGPoint, ontoPlane planeTransform: float4x4, relativeToCamera: Bool) -> SIMD3? ``` ## Parameters `point` A point in the view’s coordinate system. `planeTransform` The transform used to define the coordinate system of the plane. The coordinate system’s positive y-axis is assumed to be the normal of the plane. `relativeToCamera` If the plane transform is relative to camera space or world space. ## Return Value 3D position in world coordinates or nil if unprojection is not possible. ## Discussion A 2D point in the view’s coordinate space can refer to any point along a line segment in the 3D coordinate space. Unprojecting gets the 3D position of the point along this line segment that intersects the provided plane. --- 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)