SURFNET

A recipe for reading surfaces from Roman Laskowski's SURFNET program (for finding cavities in macromolecules) into PyMol for visualisation.

1. Create your surfaces in "CCP4" format in SURFNET.

Asides: 
A. The "endianness" of SURFNET is set to big endian by default - see the 
remarks about the SGI flag.
B.SURFNET can be compiled against ccp4 version 5 and 6 libraries 
by following the instructions in the SURFNET distribution and modifiying 
the link lines at the end of ccp4link.scr to replace 

$CLIB/libccp4.a 

with 

$CLIB/libccp4f.a $CLIB/libccp4c.a

2. Use Gerard Kleywegt's mapman from the USF RAVE package to convert the CCP4 density map to XPLOR format

e.g. in a shell on LINUX:

$ lx_mapman

MAPMAN > READ map1 gaps.den

MAPMAN > WRITE map1 gaps.xplor XPLOR 

3. Open the XPLOR map in PyMol

4. Generate a mesh or surface object from the map using isomesh or isosurface.

e.g. on the PyMol command line:

isomesh gaps_mesh, gaps, 100.0