# unprojectPoint(_:ontoPlane:orientation:viewportSize:) Returns the projection of a point from the 2D space of a view rendering the scene onto a plane in the 3D world space detected by ARKit. ``` @nonobjc func unprojectPoint(_ point: CGPoint, ontoPlane planeTransform: simd_float4x4, orientation: UIInterfaceOrientation, viewportSize: CGSize) -> simd_float3? ``` ## Parameters `point` The point in 2D view space to project onto a plane. The coordinate space for this point has its origin is in the upper left corner and a size matching the `viewportSize` parameter. `planeTransform` A transform matrix specifying the position and orientation of a plane (with infinite extent) in 3D world space. The plane is the xz-plane of the local coordinate space this transform defines. `orientation` The orientation in which the camera image is to be presented. `viewportSize` The size, in points, of the view in which the camera image is to be presented. ## Return Value The 3D point in world space where a ray projected from the specified 2D point intersects the specified plane, or `nil` if the ray does not intersect the plane. ## Discussion If you display AR content with SceneKit, the [`ARSCNView`](/documentation/ARKit/ARSCNView) class provides an otherwise equivalent [`unprojectPoint(_:ontoPlane:)`](/documentation/ARKit/ARSCNView/unprojectPoint(_:ontoPlane:)) method that requires fewer parameters (because the view can infer its orientation and size). --- 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)