我正在使用3D模型开发ARKit应用程序。为此,我使用了3D模型并添加了用于移动,旋转和缩放3D模型的手势。
现在我只面临1个问题,但是我不确定这个问题与什么有关。 3d模型是否存在问题,或者我的程序中是否缺少任何内容。
问题是我正在使用的3D模型,显示的非常大并超出了屏幕。我正在尝试缩小尺寸,但尺寸很大。
这是我的代码:
@IBOutlet var mySceneView: ARSCNView!
var selectedNode = SCNNode()
var prevLoc = CGPoint()
var touchCount : Int = 0
override func viewDidLoad() {
super.viewDidLoad()
self.lblTitle.text = self.sceneTitle
let mySCN = SCNScene.init(named: "art.scnassets/\(self.sceneImagename).scn")!
self.mySceneView.scene = mySCN
let cameraNode = SCNNode()
cameraNode.camera = SCNCamera()
cameraNode.position = SCNVector3Make(0, 0, 0)
self.mySceneView.scene.rootNode.addChildNode(cameraNode)
self.mySceneView.allowsCameraControl = true
self.mySceneView.autoenablesDefaultLighting = true
let tapGesture = UITapGestureRecognizer(target: self, action: #selector(detailPage.doHandleTap(_:)))
let panGesture = UIPanGestureRecognizer(target: self, action: #selector(detailPage.doHandlePan(_:)))
let gesturesArray = NSMutableArray()
gesturesArray.add(tapGesture)
gesturesArray.add(panGesture)
gesturesArray.addObjects(from: self.mySceneView.gestureRecognizers!)
self.mySceneView.gestureRecognizers = (gesturesArray as! [UIGestureRecognizer])
}
//MARK:- Handle Gesture
@objc func doHandlePan(_ sender: UIPanGestureRecognizer) {
var delta = sender.translation(in: self.view)
let loc = sender.location(in: self.view)
if sender.state == .began {
self.prevLoc = loc
self.touchCount = sender.numberOfTouches
} else if sender.state == .changed {
delta = CGPoint(x: loc.x - prevLoc.x, y: loc.y - prevLoc.y)
prevLoc = loc
if self.touchCount != sender.numberOfTouches {
return
}
var rotMat = SCNMatrix4()
if touchCount == 2 {
rotMat = SCNMatrix4MakeTranslation(Float(delta.x * 0.025), Float(delta.y * -0.025), 0)
} else {
let rotMatX = SCNMatrix4Rotate(SCNMatrix4Identity, Float((1.0/100) * delta.y), 1, 0, 0)
let rotMatY = SCNMatrix4Rotate(SCNMatrix4Identity, Float((1.0/100) * delta.x), 0, 1, 0)
rotMat = SCNMatrix4Mult(rotMatX, rotMatY)
}
let transMat = SCNMatrix4MakeTranslation(selectedNode.position.x, selectedNode.position.y, selectedNode.position.z)
selectedNode.transform = SCNMatrix4Mult(selectedNode.transform, SCNMatrix4Invert(transMat))
let parentNodeTransMat = SCNMatrix4MakeTranslation((selectedNode.parent?.worldPosition.x)!, (selectedNode.parent?.worldPosition.y)!, (selectedNode.parent?.worldPosition.z)!)
let parentNodeMatWOTrans = SCNMatrix4Mult(selectedNode.parent!.worldTransform, SCNMatrix4Invert(parentNodeTransMat))
selectedNode.transform = SCNMatrix4Mult(selectedNode.transform, parentNodeMatWOTrans)
let camorbitNodeTransMat = SCNMatrix4MakeTranslation((self.mySceneView.pointOfView?.worldPosition.x)!, (self.mySceneView.pointOfView?.worldPosition.y)!, (self.mySceneView.pointOfView?.worldPosition.z)!)
let camorbitNodeMatWOTrans = SCNMatrix4Mult(self.mySceneView.pointOfView!.worldTransform, SCNMatrix4Invert(camorbitNodeTransMat))
selectedNode.transform = SCNMatrix4Mult(selectedNode.transform, SCNMatrix4Invert(camorbitNodeMatWOTrans))
selectedNode.transform = SCNMatrix4Mult(selectedNode.transform, rotMat)
selectedNode.transform = SCNMatrix4Mult(selectedNode.transform, camorbitNodeMatWOTrans)
selectedNode.transform = SCNMatrix4Mult(selectedNode.transform, SCNMatrix4Invert(parentNodeMatWOTrans))
selectedNode.transform = SCNMatrix4Mult(selectedNode.transform, transMat)
}
}
@objc func doHandleTap(_ sender: UITapGestureRecognizer) {
let p = sender.location(in: self.mySceneView)
var hitResults = self.mySceneView.hitTest(p, options: nil)
if (p.x > self.mySceneView.frame.size.width-100 || p.y < 100) {
self.mySceneView.allowsCameraControl = !self.mySceneView.allowsCameraControl
}
if hitResults.count > 0 {
let result = hitResults[0]
let material = result.node.geometry?.firstMaterial
selectedNode = result.node
SCNTransaction.begin()
SCNTransaction.animationDuration = 0.3
SCNTransaction.completionBlock = {
SCNTransaction.begin()
SCNTransaction.animationDuration = 0.3
SCNTransaction.commit()
}
material?.emission.contents = UIColor.white
SCNTransaction.commit()
}
}
我的问题是:
我们可以在屏幕中心设置适合屏幕尺寸的3d对象模型Aspect的任何大小吗?请建议是否有办法。
任何指导或建议将不胜感激。
答案 0 :(得分:3)
您需要使用getBoundingSphereCenter
来获取边界球的大小,然后可以将其投影到屏幕上。或者,获取该半径与场景套件相机和对象位置之间的距离之比。这样,您将知道对象在屏幕上看起来有多大。要缩小比例,您只需设置对象的scale
属性即可。
第二部分,您可以使用projectPoint。
答案 1 :(得分:0)
我处理此问题的方法是确保3D模型始终具有固定大小。
例如,如果3D模型是小杯子还是大房子,我可以确保它在场景的坐标空间上始终具有25 cm的宽度(同时保持x y z之比)。
您可以像这样计算节点边界框的宽度:
let mySCN = SCNScene(named: "art.scnassets/\(self.sceneImagename).scn")!
let minX = mySCN.rootNode.boundingBox.min.x
let maxX = mySCN.rootNode.boundingBox.max.x
// change 0.25 to whatever you need
// this value is in meters
let scaleValue = 0.25 / abs(minX - maxX)
// scale all axes of the node using `scaleValue`
// this maintains ratios and does not stretch the model
mySCN.rootNode.scale = SCNVector3(scaleValue, scaleValue, scaleValue)
self.mySceneView.scene = mySCN
您还可以使用边界框的y或z值,根据高度或深度计算比例值。