Draw SceneKit object between two points

Question

Having made some progress in the geometry side of things I\'m moving on to putting together an entire scene. That scene has a couple dozen objects, each defined by a boundin

Answer 1

For the sake of another method, I achieved this through trigonometry. This made the code very minimal. Here is the end result:

In my case the nodes are always placed on a fixed plane that slices the Y-Axis.

// Create Cylinder Geometry                    
let line = SCNCylinder(radius: 0.002, height: node1.distance(to: node2))

// Create Material 
let material = SCNMaterial()
material.diffuse.contents = UIColor.red
material.lightingModel = .phong
line.materials = [material]

// Create Cylinder(line) Node                   
let newLine = SCNNode()
newLine.geometry = line
newLine.position = posBetween(first: node1, second: node2)

// This is the change in x,y and z between node1 and node2
let dirVector = SCNVector3Make(node2.x - node1.x, node2.y - node1.y, node2.z - node1.z)

// Get Y rotation in radians
let yAngle = atan(dirVector.x / dirVector.z)

// Rotate cylinder node about X axis so cylinder is laying down
currentLine.eulerAngles.x = .pi / 2

// Rotate cylinder node about Y axis so cylinder is pointing to each node
currentLine.eulerAngles.y = yAngle

This is the function to get the position between two nodes, place it within your class:

func posBetween(first: SCNVector3, second: SCNVector3) -> SCNVector3 {
        return SCNVector3Make((first.x + second.x) / 2, (first.y + second.y) / 2, (first.z + second.z) / 2)
}

This is the extension to get the distance between nodes for the cylinder height, place it somewhere outside of your class:

extension SCNVector3 {
    func distance(to destination: SCNVector3) -> CGFloat {
        let dx = destination.x - x
        let dy = destination.y - y
        let dz = destination.z - z
        return CGFloat(sqrt(dx*dx + dy*dy + dz*dz))
    }
}

If you don't have one fixed axis like myself then you could do the extra trig to use this method.