title: iOS SceneKit - Add Fresnel effect to material transparency
body: <p>I have a Geometry Node that pictures a human body.
  The material for the object is transparent</p>
  
  <pre><code>let node = newScene.rootNode.childNode(withName: "man_mesh", recursively: true)
  let nodeMaterial = node?.geometry?.firstMaterial
  nodeMaterial?.emission.contents = UIColor(red: 0.0, green: 0.0, blue: 1.0, alpha: 1.0)
  nodeMaterial?.transparencyMode = .rgbZero
  nodeMaterial?.transparent.contents = UIColor(red: 1.0, green: 1.0, blue: 1.0, alpha: 1.0)
  </code></pre>
  
  <p>The effect I'm trying to get is for the object to be fully transparent in areas facing the camera, but become more opaque as the polygons face sideways... this creates a sort of a shiny blue rim. something like this:  </p>
  
  <p><a href="https://i.stack.imgur.com/ppLM9.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/ppLM9.png" alt="Rim Effect"></a></p>
  
  <p>Any idea how to create this effect?</p>
  
  <p>Thanks</p>
  
  <p>EDIT: Another interesting point: it appears the SceneKit does support the fresnel effect. The effect affects the Reflectance map - as should be, however, once you apply transparency to your object, it also affects the reflectance (full transparency will make reflectance disappear as well)- I believe this is a conceptual mistake by Apple - a material can be transparent and still reflect light!</p>