The CMM writer supports points and spheres. Cylinders can be added at some point.
You are probably better off using the IMP::display::ChimeraWriter which writes a python file, readable by Chimera as it supports more types of geometry.

Public Member Functions | |
| CMMWriter (TextOutput of) | |
| virtual std::string | get_type_name () const |
| virtual ::IMP::VersionInfo | get_version_info () const |
Protected Member Functions | |
| virtual void | on_close () |
| virtual void | on_open () |