Disegna il cilindro della dashline in scenekit come l'app di misura?
Aug 20 2020
Ho seguito questa domanda per provare a realizzare il cilindro del trattino
final class LineNode: SCNNode {
convenience init(positionA: SCNVector3, positionB: SCNVector3) {
self.init()
let vector = SCNVector3(positionA.x - positionB.x, positionA.y - positionB.y, positionA.z - positionB.z)
let distance = vector.length
let midPosition = (positionA + positionB) / 2
let lineGeometry = SCNCylinder()
lineGeometry.radius = PileDrawer3D.lineWidth
lineGeometry.height = CGFloat(distance)
lineGeometry.radialSegmentCount = 5
lineGeometry.firstMaterial?.diffuse.contents = dashedImage
lineGeometry.firstMaterial?.diffuse.contentsTransform = SCNMatrix4MakeScale(distance * 10, Float(lineGeometry.radius * 10), 1)
lineGeometry.firstMaterial?.diffuse.wrapS = .repeat
lineGeometry.firstMaterial?.diffuse.wrapT = .repeat
lineGeometry.firstMaterial?.isDoubleSided = true
lineGeometry.firstMaterial?.multiply.contents = UIColor.green
lineGeometry.firstMaterial?.lightingModel = .constant
let rotation = SCNMatrix4MakeRotation(.pi / 2, 0, 0, 1)
lineGeometry.firstMaterial?.diffuse.contentsTransform = SCNMatrix4Mult(rotation, lineGeometry.firstMaterial!.diffuse.contentsTransform)
geometry = lineGeometry
position = midPosition
eulerAngles = SCNVector3.lineEulerAngles(vector: vector)
name = className
}
lazy var dashedImage: UIImage = {
let size = CGSize(width: 10, height: 3)
UIGraphicsBeginImageContextWithOptions(size, true, 0)
UIColor.white.setFill()
UIRectFill(CGRect(x: 0, y: 0, width: 7, height: size.height))
let img = UIGraphicsGetImageFromCurrentImageContext()
UIGraphicsEndImageContext()
return img!
}()
}
Tuttavia, i tubi non sono tratteggiati.

Non sono sicuro di cosa mi manchi qui per favore aiutatemi.
UpdateT:
Si scopre che il colore chiaro (nell'immagine) è reso come nero, non trasparente in SCNView. Tuttavia, non ho idea del motivo per cui il colore verde si sia scurito in questo modo.
Risposte
Eddie Sep 03 2020 at 14:08
Un altro approccio per Line & DashLine
final class LineNode: SCNNode {
var color: UIColor? {
set { geometry?.firstMaterial?.diffuse.contents = newValue }
get { geometry?.firstMaterial?.diffuse.contents as? UIColor }
}
convenience init(positionA: SCNVector3, positionB: SCNVector3, dash: CGFloat = 0, in scene: SCNScene? = nil) {
self.init()
let indices: [Int32] = [0, 1]
let source = SCNGeometrySource(vertices: [positionA, positionB])
let element = SCNGeometryElement(indices: indices, primitiveType: .line)
geometry = SCNGeometry(sources: [source], elements: [element])
geometry?.firstMaterial?.diffuse.contents = UIColor.green
geometry?.firstMaterial?.lightingModel = .constant
return
}
}
final class DashLineNode: SCNNode {
convenience init(positionA: SCNVector3, positionB: SCNVector3) {
self.init()
let vector = (positionB - positionA)
let length = floor(vector.length / 1)
let segment = vector / length
let indices:[Int32] = Array(0..<Int32(length))
var vertices = [positionA]
for _ in indices {
vertices.append(vertices.last! + segment)
}
let source = SCNGeometrySource(vertices: vertices)
let element = SCNGeometryElement(indices: indices, primitiveType: .line)
geometry = SCNGeometry(sources: [source], elements: [element])
geometry?.firstMaterial?.lightingModel = .constant
}
}