CODEWITHSUNDEEP
uibezierpathscenekitscnnode
dijipiji
dijipiji

Reputation: 3109

SceneKit draw curved line

I'd like to draw a bezier curved line with SceneKit and thought this would work:

func drawCurvedLine() {

    let scene = SCNScene()
    let scnView = self.view as! SCNView
    scnView.scene = scene
    scnView.allowsCameraControl = true

    let path = UIBezierPath()
    path.moveToPoint(CGPoint(x: -20, y: -20))
    path.addCurveToPoint(CGPoint(x: 20, y: 20),
        controlPoint1: CGPoint(x: 5, y: 5),
        controlPoint2: CGPoint(x: 15, y: 15))

    path.closePath()

    path.flatness = 0.3

    var scnShape:SCNShape = SCNShape(path: path, extrusionDepth: 2)

    scnShape.firstMaterial?.diffuse.contents = UIColor.purpleColor()
    let shapeNode = SCNNode(geometry: scnShape)
    scene.rootNode.addChildNode(shapeNode)
}

However my results are like this screenshot:SceneKit render

Does anyone know why the curveTo control points are ignored or how to switch them on? Or any other method to draw a curved line in SceneKit?

I can get this:curved

However I guess I'm looking to NOT fill the shape. Ideally a curved tubular line is what I'm trying to achieve here. ( Imagine a power cable or some such ... ). I guess I would love to have the equivalent of SCNLine or SCNTube "render on bezier path"

Upvotes: 4

Views: 3154

Answers (2)

mnuages
mnuages

Reputation: 13462

SCNShape just be built from closed Bézier paths and will always be filled (with the exception of holes). These paths can be completely custom but will always be extruded along a segment along the z axis. What you want is to extrude a circle along an arbitrary path, and that's not supported.

SCNGeometry exposes APIs that allow you to build arbitrary geometries.

Upvotes: 3

jperl
jperl

Reputation: 1106

It is working! Very well, I might add.

The problem is, all your points lie on the same line, y=x

Try changing your control points to have values where y!=x

ex,

    path.addCurveToPoint(CGPoint(x: 20, y: 20),
    controlPoint1: CGPoint(x: 15, y: 0),
    controlPoint2: CGPoint(x: 20, y: 10))

Upvotes: 2

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