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
    }
}