Crystallography‎ > ‎Molecular graphics‎ > ‎Pymol‎ > ‎

Cavities as surface

1. Show --> Surface
2. Setting --> Surface --> Cavities & Pockets Only
3. set cavity_cull, 40

Also see:

Surface_cavity_mode: http://www.pymolwiki.org/index.php/Surface_cavity_mode

Example: