Scene Kit - 3D Wireframe Mesh

3D wireframe mesh scenes rendered in Scene Kit using the SCNGeometryPrimitiveTypeLine enum.
The API for SCNGeometryPrimitiveTypeLine is undocumented but a partial example exists in the
WWDC 2014 Scene Kit session sample code.

The Line enum appears to work only with the built-in primitive geometry shapes.
Using it with non-primitive models such as Bruce (Boss.dae) results in a Terminator effect.
The character model geometry data seems correct and importing the DAE file into Blender worked (bottom),
so this is likely a user error or a bug.

SCNGeometryPrimitiveType
  SCNGeometryPrimitiveTypeTriangles     = 0
  SCNGeometryPrimitiveTypeTriangleStrip = 1
  SCNGeometryPrimitiveTypeLine          = 2
  SCNGeometryPrimitiveTypePoint         = 3

* Source code and assets are from the WWDC 2014 Scene Kit session sample code.