Esben, The two algorithms are different. For efficiency & performance reasons, PyMOL by default uses an anisotropic marching tetrahedrons algorithm, which ends up generating fewer triangles along (+X,+Y,+Z). Note that
map_double map-name can increase sampling, but the result still suffers from anisotropy. Hmm...now that the "marching cubes" patent has finally expired, we really should implement that in PyMOL as well :)! Cheers, Warren > -----Original Message----- > From: pymol-users-boun...@lists.sourceforge.net > [mailto:pymol-users-boun...@lists.sourceforge.net] On Behalf > Of Esben Jannik Bjerrum > Sent: Monday, July 24, 2006 8:31 AM > To: pymol-users@lists.sourceforge.net > Subject: [PyMOL] Difference in isosurface and isomesh > representations withindexed brick object. > > Hi > Im using Pymol as a 3d plotter of some "volume density data". > However, theres a difference in surface or mesh > representations near zero. > The following script illustrate(doesnt work without recompile > of NumPy support into pymol on linux, but works on both mac > and windows > directly) > > from chempy.brick import Brick > brik2=Brick() > brik2.setup_from_min_max( > [0,0,0], > [2,2,2], > [1,1,1]) > brik2.lvl[1,1,1]=1 > cmd.load_brick(brik2,"brick") > for a in range(2): > lvl = a/2. > cmd.do("isomesh lvlmesh%1.1f,brick,%1.1f" %(lvl,lvl)) > cmd.do("isosurface lvlsurf%1.1f,brick,%1.1f" %(lvl,lvl)) > > it seems like the isosurface do not get interpolated to > certain diagonal points, but not to other, while the mesh > only gets interpolated to neighbor points. Its probably not a > problem for "normal" data, but as I have sparse and indexed > data it do look a bit strange. Is there a way to make > isosurface behave like isomesh in that regard or add the > missing interpolation to diagonal points? > > Esben > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection > around http://mail.yahoo.com > > -------------------------------------------------------------- > ----------- > Take Surveys. Earn Cash. Influence the Future of IT Join > SourceForge.net's Techsay panel and you'll get the chance to > share your opinions on IT & business topics through brief > surveys -- and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge &CID=DEVDEV > _______________________________________________ > PyMOL-users mailing list > PyMOL-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/pymol-users >
