Question

我一直试图在水平面上放置一个三维物体，但放置的3d物体没有固定在它的位置。

目前我可以将3d物体放置在水平面上，但放置三维物体在水平面上移动。放置的3d物体没有固定到它的位置。

这是我试图将3d对象放置在固定位置的代码：

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

        if let touch = touches.first {

            // gives us the location of where we touched on the 2D screen.
            let touchLocation = touch.location(in: sceneView)

            // hitTest is performed to get the 3D coordinates corresponding to the 2D coordinates that we got from touching the screen.
            // That 3d coordinate will only be considered when it is on the existing plane that we detected.
            let results = sceneView.hitTest(touchLocation, types: .existingPlaneUsingExtent)

            // if we have got some results using the hitTest then do this.
            if let hitResult = results.first {


                let boxScene = SCNScene(named: "art.scnassets/porsche.scn")!
                //           var  boxScene = SCNScene(named: "art.scnassets/porsche.scn")!


                if let boxNode = boxScene.rootNode.childNode(withName: "car", recursively: true) {
                    print("box:::\(boxNode.childNodes)")


                    boxNode.position = SCNVector3(x: hitResult.worldTransform.columns.3.x, y: hitResult.worldTransform.columns.3.y, z: hitResult.worldTransform.columns.3.z)



                    // finally the box is added to the scene.
                    sceneView.scene.rootNode.addChildNode(boxNode)

                }


            }

        }
    }

以下是检测平面的代码：

  func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {

                if anchor is ARPlaneAnchor {

         anchors can be of many types, as we are just dealing with horizontal plane detection we need to downcast anchor to ARPlaneAnchor
                    let planeAnchor = anchor as! ARPlaneAnchor

         creating a plane geometry with the help of dimentions we got using plane anchor.
                    let plane = SCNPlane(width: CGFloat(planeAnchor.extent.x), height: CGFloat(planeAnchor.extent.z))

                    // a node is basically a position.
                    let planeNode = SCNNode()

         setting the position of the plane geometry to the position we got using plane anchor.
                    planeNode.position = SCNVector3(x: planeAnchor.center.x, y: 0, z: planeAnchor.center.z)

                    // when a plane is created its created in xy plane instead of xz plane, so we need to rotate it along x axis.
                    planeNode.transform = SCNMatrix4MakeRotation(-Float.pi/2, 1, 0, 0)

                    //create a material object
                    let gridMaterial = SCNMaterial()

                    //setting the material as an image. A material can also be set to a color.
                    gridMaterial.diffuse.contents = UIImage(named: "art.scnassets/grid.png")

                    // assigning the material to the plane
                    plane.materials = [gridMaterial]


                    // assigning the position to the plane
                    planeNode.geometry = plane

                    //adding the plane node in our scene
                    node.addChildNode(planeNode)



                }

                else {

                    return
                }
        }

Answer 1

我认为您需要为您的模型创建ARAnchor：

无论何时放置虚拟对象，都要添加ARAnchor 表示其对ARSession的位置和方向。后移动虚拟对象，删除旧位置的锚点在新位置创建一个新锚点。添加锚告诉ARKit 一个位置很重要，提高世界跟踪质量区域和帮助虚拟对象看起来相对于现实世界的表面。

因此，这可能会指向正确的方向：

1st：创建一个引用你的boxNode的变量：

var boxNode: SCNNode?

第二名：在触摸位置创建ARAnchor，例如：

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

    //1. Get The Current Touch Location & Perform An ARSCNHitTest
    guard let currentTouchLocation = touches.first?.location(in: sceneView),
        let hitTest = sceneView.hitTest(currentTouchLocation, types: .existingPlaneUsingExtent).first else { return }

    //2. Create An Anchor At The World Transform
    let anchor = ARAnchor(transform: hitTest.worldTransform)

    //3. Add It To The Scene
    sceneView.add(anchor: anchor)

}

第3名：rendererDidAddNode delegate callback初始化模型：

func renderer(_ renderer: SCNSceneRenderer, didAdd node: SCNNode, for anchor: ARAnchor) {

    //1. If We Havent Created Our Box Node Then Create It
    if  boxNode == nil{

        //a. Check That Our SCNScene Is Valid
        guard let validScene =  SCNScene(named: "art.scnassets/porsche.scn"),
              let carRoot = validScene.rootNode.childNode(withName: "car", recursively: true) else { return }

        //b. Set The BoxNodes Position And Add It To The Anchor
        boxNode = carRoot
        boxNode?.position = SCNVector3(anchor.transform.columns.3.x, anchor.transform.columns.3.y, anchor.transform.columns.3.z)
        node.addChildNode(boxNode!)

    }
}

希望它有所帮助...

如何在iOS 11中将3d对象放置在水平面的固定位置？

1 个答案: