To accomplish zero collision, you'll also need to install the third party package Panda3D SDK from:
Panda3D provides a python wrapper for the open-source physics engine "Bullet" which is the same base engine used for the physics engines of most professional packages such as Maya, Cinema4D, Blender, etc.
We recommend finding a 64 bit version, like this one for Mac:
autoPACK will recognize the default Panda install and you shouldn't need to set up any links/paths.
Be sure to follow the installation instructions https://www.panda3d.org/manual/index.php/Getting_Started_on_OSX
which means installing NVIDIA cg Toolkit
You can run the 32 bit version 1.8.x in Windows, or you can wait for us to post a 64 bit Windows compilation by January 20, 2014.