Having some PCB design to do, I just installed KiCAD on my MacBook (20151104 nightly build).
As I'm a beginner with KiCAD, I went through the tutorial. Everything went well (I'm impressed by its quality). But when I tried to display the 3D view of my first design, only the PCB was visible.
I found that KISYS3DMOD path was not defined correctly in my installation. Its value was /Library/Application Support/kicad/modules/packages3d while it should have been /Library/Application Support/kicad/packages3d.
Updating the path is done from KiCAD project manager window, using Preferences / Configure Paths.
Update: I wanted to report this problem on KiCAD bug tracker, but saw that it had already been reported.