如何在iOS 11 ARKit-Scenekit中为SCNNode创建边框以指示其选择？

Question

如何绘制边框以突出显示SCNNode并向用户指示该节点已被选中？在我的项目中,用户可以放置多个虚拟对象,用户可以随时选择任何对象.选择后,我应该向用户显示高亮显示的3D对象.有没有办法直接实现这个或在SCNNode上绘制边框？

Answer 1

您需要添加一个轻击手势识别器sceneView.

// add a tap gesture recognizer
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(handleTap(_:)))
scnView.addGestureRecognizer(tapGesture)

然后,处理点击并突出显示节点:

@objc
func handleTap(_ gestureRecognize: UIGestureRecognizer) {
    // retrieve the SCNView
    let scnView = self.view as! SCNView

    // check what nodes are tapped
    let p = gestureRecognize.location(in: scnView)
    let hitResults = scnView.hitTest(p, options: [:])
    // check that we clicked on at least one object
    if hitResults.count > 0 {
        // retrieved the first clicked object
        let result = hitResults[0]

        // get its material
        let material = result.node.geometry!.firstMaterial!

        // highlight it
        SCNTransaction.begin()
        SCNTransaction.animationDuration = 0.5

        // on completion - unhighlight
        SCNTransaction.completionBlock = {
            SCNTransaction.begin()
            SCNTransaction.animationDuration = 0.5

            material.emission.contents = UIColor.black

            SCNTransaction.commit()
        }

        material.emission.contents = UIColor.red

        SCNTransaction.commit()
    }
}

上面的代码段突出显示整个节点.你必须调整它才能突出显示边框,如果这是你正在寻找的.

免责声明:
此代码直接取自Xcode在打开新游戏(SceneKit)项目时创建的模板代码.