Add SCNNode or UIView to the center of SCNView in order to detect other SCNNodes - swift

Question

I am trying to center a UIView to the center of my SCNView in Order to detect the other added SCNTorus nodes in my scene.
I added a view to the center of my sceneView like below
var focusPoint: CGPoint {
return CGPoint(
x: sceneView.bounds.size.width / 2,
y: sceneView.bounds.size.height - (sceneView.bounds.size.height / 1.618))
}
Then I tried two ways :
1 -
func renderer(_ renderer: SCNSceneRenderer, updateAtTime time: TimeInterval) {
DispatchQueue.main.async { [weak self] in
guard let strongSelf = self else { return }
if !strongSelf.inEditMode { return }
for node in strongSelf.selectionRingsNodes {
let projectedPoint = renderer.projectPoint(node.position)
let projectedCGPoint = CGPoint(x: CGFloat(projectedPoint.x), y: CGFloat(projectedPoint.y))
let distance = projectedCGPoint.distance(to: strongSelf.focusPoint)
if distance < 20 {
print(node.name)
}
}
}
}
2 -
func renderer(_ renderer: SCNSceneRenderer, updateAtTime time: TimeInterval) {
DispatchQueue.main.async { [weak self] in
guard let strongSelf = self else { return }
if !strongSelf.inEditMode { return }
for node in strongSelf.selectionRingsNodes {
let (min, max) = node.boundingBox
let projectedMinPoint = renderer.projectPoint(min)
let projectedMinCGPoint = CGPoint(x: CGFloat(projectedMinPoint.x), y: CGFloat(projectedMinPoint.y))
let projectedMaxPoint = renderer.projectPoint(max)
let projectedMaxCGPoint = CGPoint(x: CGFloat(projectedMaxPoint.x), y: CGFloat(projectedMaxPoint.y))
let minX = CGFloat(projectedMinCGPoint.x)
let maxX = CGFloat(projectedMaxCGPoint.x)
let minY = CGFloat(projectedMinCGPoint.y)
let maxY = CGFloat(projectedMaxCGPoint.y)
let nodeRect = CGRect(x: minX, y: minY, width: maxX - minX, height: maxY - minY)
if nodeRect.contains(strongSelf.focusPoint) {
print(node.name)
}
}
}
}
These two methods return the wrong results, a very big distance, and very big x and y.

Answer 1

Finally I Got the solution!
It turned out that I should convert the position to the scene’s world coordinate space, using this method convertPosition(SCNVector3,to:)
Here the complete code :
func renderer(_ renderer: SCNSceneRenderer, updateAtTime time: TimeInterval) {
DispatchQueue.main.async { [weak self] in
guard let strongSelf = self else { return }
if !strongSelf.inEditMode { return }
for node in strongSelf.selectionRingsNodes {
let position = node.convertPosition(SCNVector3Zero, to: nil)
let projectedPoint = renderer.projectPoint(position)
let projectedCGPoint = CGPoint(x: CGFloat(projectedPoint.x), y: CGFloat(projectedPoint.y))
let distance = projectedCGPoint.distance(to: strongSelf.focusPoint)
if distance < 50 {
strongSelf.showToast(message: node.getTopMostParentNode().name!, font: .systemFont(ofSize: 30))
}
}
}
}