---
title: "unprojectPoint(_:ontoPlane:viewRotationAngle:viewportSize:)"
framework: arkit
role: symbol
role_heading: Instance Method
platforms: [iOS 27.0+, iPadOS 27.0+]
path: "arkit/arcamera/unprojectpoint(_:ontoplane:viewrotationangle:viewportsize:)"
---

# unprojectPoint(_:ontoPlane:viewRotationAngle:viewportSize:)

Unprojects a 2D point in image space onto a 3D plane in world space.

## Declaration

```swift
@nonobjc func unprojectPoint(_ point: CGPoint, ontoPlane planeTransform: simd_float4x4, viewRotationAngle: CGFloat, viewportSize: CGSize) -> simd_float3?
```

## Parameters

- `point`: The 2D point in the image to unproject.
- `planeTransform`: The 4x4 matrix representing the plane in world space.
- `viewRotationAngle`: The view rotation angle, in degrees. Prefer it over an interface orientation, whose reported value cannot always be relied upon. Obtain it from ARSession.viewRotationAngle.
- `viewportSize`: The size of the viewport.

## Return Value

Return Value The 3D point in world space, or nil if the point cannot be unprojected.