---
title: "raycast(_:)"
framework: arkit
role: symbol
role_heading: Instance Method
path: "arkit/arsession/raycast(_:)"
---

# raycast(_:)

Checks once for intersections between a ray and real-world surfaces.

## Declaration

```swift
func raycast(_ query: ARRaycastQuery) -> [ARRaycastResult]
```

## Parameters

- `query`: The ray you create from a screen point you’re interested in.

## Return Value

Return Value An array of ray-cast results, sorted from nearest to furthest from the camera. The array is empty if the ray cast fails to find an intersection between the query’s ray and a real-world surface.

## Discussion

Discussion Ray casting provides a 3D location in physical space that corresponds to a given 2D location on the screen. When you call this function, it succeeds in returning a result when a mathematical ray that ARKit casts outward from the user intersects with any real-world surfaces that ARKit detects in the physical environment.

## See Also

### Finding real-world surfaces

- [trackedRaycast(_:updateHandler:)](arkit/arsession/trackedraycast(_:updatehandler:).md)