show masking on object which is between camera and wall using RealityKit - swift

Question

I made a video for generating a floor plan in which I need to capture the wall and floor together at a certain position if a user is too near to the wall or if any object come between the camera and wall/floor then need to show Too Close mask on that object something like display in this video.
I try to use rycast in session(_ session: ARSession, didUpdate frame: ARFrame) method but I am very new in AR and not know which method we need to use.
func session(_ session: ARSession, didUpdate frame: ARFrame) {
guard let query = self.arView?.makeRaycastQuery(from: self.arView?.center ?? CGPoint.zero,
allowing: .estimatedPlane,
alignment: .any)
else { return }
guard let raycastResult = self.arView?.session.raycast(query).first
else { return }
let currentPositionOfCamera = raycastResult.worldTransform.getPosition()
if currentPositionOfCamera != .zero {
let distanceFromCamera = frame.camera.transform.getPosition().distanceFrom(position: currentPositionOfCamera)
print("Distance from raycast:",distanceFromCamera)
if (distance < 0.5) {
print("Too Close")
}
}
}

Answer 1

I am just learning ARKit and RealityKit as well, but wouldn't your code be:
let currentPositionOfCamera = self.arView.cameraTransform.translation
if currentPositionOfCamera != .zero {
// distance is defined in simd as the distance between 2 points
let distanceFromCamera = distance(raycastResult.worldTransform.position, currentPositionOfCamera)
print("Distance from raycast:",distanceFromCamera)
if (distanceFromCamera < 0.5) {
print("Too Close")
let rayDirection = normalize(raycastResult.worldTransform.position - self.arView.cameraTransform.translation)
// This pulls the text back toward the camera from the plane
let textPositionInWorldCoordinates = result.worldTransform.position - (rayDirection * 0.1)
let textEntity = self.model(for: classification)
// This scales the text so it is of a consistent size
textEntity.scale = .one * raycastDistance
var textPositionWithCameraOrientation = self.arView.cameraTransform
textPositionWithCameraOrientation.translation = textPositionInWorldCoordinates
// self.textAnchor is defined somewhere in the class as an optional
self.textAnchor = AnchorEntity(world: textPositionWithCameraOrientation.matrix)
textAnchor.addChild(textEntity)
self.arView.scene.addAnchor(textAnchor)
} else {
guard let textAnchor = self.textAnchor else { return }
self.removeAnchor(textAnchor)
}
}
// Creates a text ModelEntity
func tooCloseModel() -> ModelEntity {
let lineHeight: CGFloat = 0.05
let font = MeshResource.Font.systemFont(ofSize: lineHeight)
let textMesh = MeshResource.generateText("Too Close", extrusionDepth: Float(lineHeight * 0.1), font: font)
let textMaterial = SimpleMaterial(color: classification.color, isMetallic: true)
let model = ModelEntity(mesh: textMesh, materials: [textMaterial])
// Center the text
model.position.x -= model.visualBounds(relativeTo: nil).extents.x / 2
return model
}
This code is adapted from Apple's Visualizing Scene Semantics.