How to put an anchor on reconstructed mesh to get accuracy

Question

I am exploring lidar and its feature in ARKit. I am thinking of raycast position(x,y) on the lidar mesh. That means I want to put an anchor on the lidar mesh for the raycasted position. The goal is to keep anchor objects sticky and accurate on surface/mesh. Below image gives better understanding

How to get Mesh position instead of default ARWorld position in raycast. That means, How to put anchor or box upon specific position of mesh/ARMeshAnchor?

@AndyFedoroff On mesh/using lidar, I want to put anchor at tapped/raycasted position. another way I can say, How to raycast mesh position using the center point of screen — indrajit, Jul 15 '21 at 09:33
If we raycast in ARKit, We get a position in the context of the plane, I want to check if there is mesh data available then put the anchor on it instead of raycasted position. — indrajit, Jul 15 '21 at 09:37
For better result ask just one question per post.))) Insert the first question into this post and second question into another one. — Andy Jazz, Jul 15 '21 at 10:07
https://stackoverflow.com/questions/56466773/what-is-the-real-benefit-of-using-raycast-in-arkit-and-realitykit/56467767#56467767 — Andy Jazz, Jul 15 '21 at 10:13
I do have only one question, How to get Mesh position instead of default ARWorld position in raycast. That means, How to put anchor or box upon specific position of mesh/ARMeshAnchor. — indrajit, Jul 15 '21 at 10:25

score 2 · Accepted Answer · answered Jul 15 '21 at 11:07

It works with any LiDAR's reconstructed mesh, not only with planes:

@objc func tapped(_ sender: UITapGestureRecognizer) {
    
    let tapLocation = sender.location(in: arView)
    
    if let result: ARRaycastResult = arView.raycast(from: tapLocation,
                                                allowing: .estimatedPlane,
                                               alignment: .any).first {
        
        let resultAnchor = AnchorEntity(world: result.worldTransform)
        
        resultAnchor.addChild(self.sphereObject(0.05, .systemRed))
        
        arView.scene.addAnchor(resultAnchor, removerAfter: 10.0)
    }
}

How to put an anchor on reconstructed mesh to get accuracy

1 Answers1