ios - 如何更改绘图线的粗细？

Question

private func lineFrom(vector vector1: SCNVector3, toVector vector2: SCNVector3) -> SCNGeometry {

        let indices: [Int32] = [0,1]
        let source = SCNGeometrySource(vertices: [vector1, vector2])
        let element = SCNGeometryElement(indices: indices, primitiveType: .line)
        return SCNGeometry(sources: [source], elements: [element])
    }


@objc private func tapped(rec: UITapGestureRecognizer) {

    let hitTransform = SCNMatrix4(hit.worldTransform)

                let hitPoint = SCNVector3Make(hitTransform.m41 , hitTransform.m42, hitTransform.m43)

                if points.start == nil{
                    print("start touch")
                    points.start = hitPoint
                    print(points.start!.x, points.start!.y, points.start!.z)

                } 

        else{
                    points.end = hitPoint
                    print(points.end!.x, points.end!.y, points.end!.z

                    line.geometry = lineFrom(vector: points.start!, toVector: points.end!)

                    line.geometry?.firstMaterial?.diffuse.contents = UIColor.red
                    line.geometry?.firstMaterial?.isDoubleSided = true

                    sceneView.scene.rootNode.addChildNode(line)
                    func renderer(_ renderer: SCNSceneRenderer, willRenderScene scene: SCNScene, atTime time: TimeInterval) {
                        glLineWidth(80)
                     }
                    canPlacePoint = false
                }
            }
        }
}

我触摸两个点来保存位置，并尝试画一条连接这两点的线。虽然画了线，但触摸点的位置不正确。 我还用了glLineWidth()，因为我想改变画线的粗细，但是它没有改变。我该怎么办？

Answer 1

SCeneKit 更喜欢使用 Metal 而不是 OpenGl，而在 Metal 中无法绘制粗线；此外，OpenGl 现已弃用。您需要使用三角形来绘制脂肪线。