如何比较场景套件中两个球体的大小？

Question

我在同一地点的项目中有2个球体。 firstSphere较小，tempSphere较大。

编辑： 第一个图形会比tempShape大。当我停下，我想测试就像firstShape“如果firstShape.scale == tempShape.scale”

//Create Shape 
let firstShapeGeo = SCNSphere(radius: shapeRadius) 
firstShape.geometry = firstShapeGeo 
let shapeMaterial = SCNMaterial() 
shapeMaterial.diffuse.contents = UIColor(colorLiteralRed: 0.2, green: 0.8, blue: 0.9, alpha: 1.0) 
firstShapeGeo.materials = [shapeMaterial] 
firstShape.position = SCNVector3Make(0, 0, 0) 
scene.rootNode.addChildNode(firstShape) 
firstShape.name = "\(shapeNumber)" 

// Create Temp Shape 
tempShapeRadius = shapeRadius + 1.0 

let tempShapeGeo = SCNSphere(radius: tempShapeRadius) 
tempShape.geometry = tempShapeGeo 
let tempShapeMaterial = SCNMaterial() 
tempShapeMaterial.diffuse.contents = UIColor(colorLiteralRed: 0.2, green: 0.8, blue: 0.9, alpha: 0.5) 
tempShapeGeo.materials = [tempShapeMaterial] 
firstShape.position = SCNVector3Make(0, 0, 0) 
scene.rootNode.addChildNode(tempShape) 

这就是我正在变的firstSphere

let grow = SCNAction.scale(to: tempShapeRadius * 2 + 1, duration: 1) 
let shrink = SCNAction.scale(to: tempShapeRadius, duration: 1) 

let sequence = SCNAction.sequence([grow, shrink]) 
firstShape.run(SCNAction.repeatForever(sequence)) 

较小的范围越来越大通过使用SCNAction.scale更大，所以我不相信半径实际上在变化。不知道这是否是你需要知道的。

任何帮助将不胜感激！谢谢！

Answer 1

为两个球体指定相同的半径。将您的tempShape的scale设置为任何值，使其大于firstShape的初始值。现在你只需要比较scale。

假设您希望tempShape球体的大小是可调球体的3倍。

let tempScale: CGFloat = 3.0 
tempShape.scale = SCNVector3(tempScale, tempScale, tempScale) 
// grow from 1 to tempScale, then back to 1 
let grow = SCNAction.scaleTo(tempScale, duration: 1) 
let shrink = SCNAction.scaleTo(1, duration: 1) 
let sequence = SCNAction.sequence([grow, shrink]) 
firstShape.run(SCNAction.repeatForever(sequence))