When using Xcode 7 and creating a new SceneKit OS X project, it seems to default to using Metal for the SCNView.
If I try to do this after creating a new Game project in Xcode 7:
var context = gameView.context
The result is nil. The view is using Metal and not OpenGL.
However, creating the same in Xcode 6.4, the context exists like expected.
How can I force my SCNView to use OpenGL and not Metal?
When creating an SCNView, you have an option to set the renderer in the initialiser:
These are the options you have available, Metal or OpenGL ES 2.0 (3.0 will likely come later):
So setting to SCNRenderingAPIOpenGLES2 will get you what you want, a forcibly OpenGL ES 2.0 rendered SceneKit View