CODEWITHSUNDEEP
swiftarkit
YMonnier
YMonnier

Reputation: 1429

ARKit image detection orientation

Apple has realised ARKit beta 1.5 with some additional features. (vertical plane detection, image detection, ...)

I am working on image detection and I would like to know how can we get orientation information when detecting images? (vertical / horizontal image detection)

The only way to get this information is with ARPlaneAnchor.Alignment.

On Apple sample project, they assume the image is horizontal in its local space.

func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {
    guard let imageAnchor = anchor as? ARImageAnchor else { return }
    let referenceImage = imageAnchor.referenceImage
    updateQueue.async {

        // Create a plane to visualize the initial position of the detected image.
        let plane = SCNPlane(width: referenceImage.physicalSize.width,
                             height: referenceImage.physicalSize.height)
        let planeNode = SCNNode(geometry: plane)
        planeNode.opacity = 0.25

        /*
         `SCNPlane` is vertically oriented in its local coordinate space, but
         `ARImageAnchor` assumes the image is horizontal in its local space, so
         rotate the plane to match.
         */
        planeNode.eulerAngles.x = -.pi / 2

        /*
         Image anchors are not tracked after initial detection, so create an
         animation that limits the duration for which the plane visualization appears.
         */
        planeNode.runAction(self.imageHighlightAction)

        // Add the plane visualization to the scene.
        node.addChildNode(planeNode)
    }
}

Upvotes: 0

Views: 1378

Answers (2)

Denis Markov
Denis Markov

Reputation: 157

In ARKit apps, that uses both vertical and horizontal planes detection, we can get plane orientation by using property ARPlaneAnchor.Alignment.

Upvotes: 0

PongBongoSaurus
PongBongoSaurus

Reputation: 7385

I am not entirely sure if this is correct, but hopefully this will help you or at least get you started.

I think you would need to get look at getting data from the camera to help with this. For example:

   func renderer(_ renderer: SCNSceneRenderer, didRenderScene scene: SCNScene, atTime time: TimeInterval) {

    /*
    Get The Pitch (Rotation Around X Axis)
    Get The Yaw (Rotation Around Y Axis)
    Get The Roll (Rotation Around Z Axis)
    */
    guard let pitch = self.augmentedRealityView.session.currentFrame?.camera.eulerAngles.x,
          let yaw =   self.augmentedRealityView.session.currentFrame?.camera.eulerAngles.y,
          let roll = self.augmentedRealityView.session.currentFrame?.camera.eulerAngles.z else { return }

    print("""
     Pitch = \(degreesFrom(pitch))
     Yaw = \(degreesFrom(yaw))
     Roll = \(degreesFrom(roll))
    """)
}


/// Convert Radians To Degrees
///
/// - Parameter radian: Float
/// - Returns: Float
func degreesFrom( _ radian: Float) -> Float{

    return radian * Float(180.0 / Double.pi)

}

enter image description here

Then you can determine (approximately) whether the device is in a horizontal or vertical position.

Upvotes: 2

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