The Reactor dynamics system has been retired and REMOVED from 3ds Max 2012.
You can access all the collisions stored by Reactor- see Interface: reactorInterface for details on collision-related methods.
The following MAXScript code returns a list of Collision_Info ReferenceTarget objects, which in turn contain information about the single collisions:
You can access the collision information via the followinginterface:
Get/Set the time of the collision.
Get/Set the first collision node.
Get/Set the second collision node.
Get/Set the name of the first collision node.
Get/Set the name of the second collision node.
Get/Set the world space collision point.
Get/Set the world space normal vector from the second to the first node.
Get/Set the relative velocity between the two collision nodes along the normal vector.
Get/Set the phantom property of the collision.
Obviously, since all properties are both read and write enabled, you can not only access the actual collision parameters, but set up your own collisions and write the information back toReactorusing the .setStoredCollisions method in the Interface: reactorInterface
See also the Reactor Online Help for additional information and examples of Stored Collision Info and MAXScript access.