title: How to show an image instead of a SCNSphere in Swift 3?
body: <p>I am creating an app where I have a SCNSphere showing, but for some reason I tried figuring it out how to put an image from my assets instead of using the built in geometry that Apple has. So, my question is how can I show a image showing in my SceneKit app instead of the SCNSphere. 
  Thanks for any help. </p>
  
  <pre><code>let personGeo = SCNSphere(radius: 0.2)
  person = SCNNode(geometry: personGeo)
  
  let personMat = SCNMaterial()
  personMat.diffuse.contents = UIColor.cyan
  personGeo.materials = [personMat]
  person.position = SCNVector3Make(0, 1.1, 0)
  
  
  person.physicsBody = SCNPhysicsBody(type: SCNPhysicsBodyType.static, shape: SCNPhysicsShape(node: person, options: nil))
  person.physicsBody?.categoryBitMask = bodyNames.Person
  person.physicsBody?.collisionBitMask = bodyNames.Coin
  person.physicsBody?.contactTestBitMask = bodyNames.Coin
  person.physicsBody?.isAffectedByGravity = false
  
  scene.rootNode.addChildNode(person) 
  </code></pre>