How to remove scnplane when touching again?

问题

I can able to add new scnplane when user tap on plane. But now, tap on same scnplane it adds again new scnplane instead of removing.

Initially when reference image is detected , It will list cake in side of menu card with image, name and ratings. And user tap on rating, it will list user ratings.

here is the code which i tried:

  override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

    //1. Get The Current Touch Location & Perform An ARSCNHitTest To Check For Any Hit SCNNode's
    guard let currentTouchLocation = touches.first?.location(in: self.sceneView),
        let hitTestNode = self.sceneView.hitTest(currentTouchLocation, options: nil).first?.node else { return }


    if let lableName = hitTestNode.name {
        print("touch working")
        if lableName == "lableNode"{


            makeCakeOnNode(hitTestNode)



        } else if lableName == "AllLabelNode" {

            makeCakeOnNode1(hitTestNode)

        } else if lableName == "fruitNode" {

            makeCakeOnNode2(hitTestNode)

        }

    }
}


func makeCakeOnNode(_ node: SCNNode){

    let planeGeometry = SCNPlane(width: 0.18  , height: 0.15)

    planeGeometry.firstMaterial?.diffuse.contents = UIColor.black.withAlphaComponent(0)




    planeNode0 = SCNNode(geometry: planeGeometry)
    planeNode0?.runAction(SCNAction.moveBy(x: -0.2, y: -0.15, z: 0, duration: 0))

                    let overlayNode = self.getNode(withImageName: "menu")
                    print("overlay::\(overlayNode)")

    let newPlane = SCNPlane(width: 0.15, height: 0.10)
    newPlane.firstMaterial?.diffuse.contents = UIImage(named: "cake_detail")

    let newPlaneNode = SCNNode(geometry: newPlane)
    newPlaneNode.eulerAngles.x = -.pi / 2
    newPlaneNode.runAction(SCNAction.moveBy(x: -0.2, y: -0.15, z: 0, duration: 0))

    node.addChildNode(planeNode0!)
    planeNode0?.addChildNode(overlayNode)
    planeNode0?.addChildNode(newPlaneNode)
    if planeBool == true {

        planeNode1?.isHidden = true
        planeNode2?.isHidden = true
        planeNode0?.isHidden = false
        planeBool = false

    } else {

        print("plane removed")
        planeNode0?.isHidden = true
        planeNode1?.isHidden = true
        planeNode2?.isHidden = true

        planeBool = true
    }


}

回答1:

One approach you can use, is to create a global variable for each of the nodes you are adding e.g:

 var labelNode: SCNNode?
 var allLabelNode: SCNNode?
 var fruitNode: SCNNode?

Then you can perform a test to see if they are nil. If the node is nil, then create it, else remove it e.g:

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {

    //1. Get The Current Touch Location & Perform An ARSCNHitTest To Check For Any Hit SCNNode's
    guard let currentTouchLocation = touches.first?.location(in: self. self.sceneView),
        let hitTestNode = self.sceneView.hitTest(currentTouchLocation, options: nil).first?.node
        else { return }

    //2. Enumerate The Nodes We Have By Name
    switch hitTestNode.name {
    case "lableNode":

        //1. If The LabelNode Doesnt Exist Create It
        if labelNode == nil{
            //Create The Node Here
        }else{
           labelNode?.removeFromParentNode()
           labelNode = nil
        }

    case "AllLabelNode":

        //2. If The LabelNode Doesnt Exist Create It
        if allLabelNode == nil{
            //Create The Node Here
        }else{
            allLabelNode?.removeFromParentNode()
            allLabelNode = nil
        }

    case "fruitNode":

        //3. If The LabelNode Doesnt Exist Create It
        if fruitNode == nil{
            //Create The Node Here
        }else{
            fruitNode?.removeFromParentNode()
            fruitNode = nil
        }

    default:
        return
    }

}

Please note that the Touches method should probably be refactored, but it should be more than enough to point you in the right direction...

来源：https://stackoverflow.com/questions/52584462/how-to-remove-scnplane-when-touching-again