On Jan 25, 2010, at 3:20 PM, Keren Lasker wrote:
> To get the particles within a rigid body, it is better using IMP::core::get_leaves or get_members, Maybe :-) They do different things (that might happen to have the same result sometimes).
> i.e.: does get_members return the leaves or the children of the RigidBody ? neither, it returns all particles which move rigidly with the rigid body.
Basically, when you have a shape that happens to be rigid, there are many sets of particles associated with it - all particles which movie rigidly with the shape (the rigid members) - the set of particles which defines the highest resolution description of the shape (which, if the rigid body is created from a molecular hierarchy, would be the leaves) - the set of particles which defines the coarsest description of the shape. Typically this is just the rigid body particle itself with a radius - the set of particles defining the residues in the rigid body - the particles defining the sphere hierarchy used for collision detection between that rigid hierarchy and another rigid hierarchy (which would be members, if they existed) etc.
Depending on what you want to do, you will need different ones of these sets.