August 2013 - Chimera-users - RBVI Mailing Lists

Re: [Chimera-users] some questions about Chimera
by Elaine Meng 05 Aug '13

05 Aug '13

> From: "Graham Johnson (qb3@UCSF)" <graham(a)grahamj.com> > Subject: Re: [Chimera-users] some questions about Chimera > Date: August 5, 2013 11:59:03 AM PDT > To: Ruijie Chen <spider32123(a)gmail.com> > > Hi Ruijie, > The "missing" colors are in the .dae or .wrl file, however, programs like Maya do not know how to read them (i.e., they only read and display the geometry, not the color-per-vertex colors). For doing this type of work, I recommend installing ePMV to directly manipulate your models in Maya. There are many things that ePMV cannot do where a Chimera–>universalFile–>Maya protocol is still useful, but ePMV will handle most of your goals. > http://epmv.scripps.edu > > Regards, > Graham > > Graham Johnson PhD > qb3@UCSF Fellow > UCSF Lab: http://mesoscope.org > Medical Illustration: http://grahamj.com > > On Aug 5, 2013, at 10:59 AM, Conrad Huang <conrad(a)cgl.ucsf.edu> wrote: >>> Dear Sir / Madam: >>> >>> I am a 3D animation student who recently started to making medical animation videos, and I found Chimera is a very usefull tool for building molecules and proteins. >>> >>> However, there are few things that I don't understand: >>> >>> 1. After I import a .dae file which exported from hemoglobin (PDB: 2hhb), I found that the color I have set for each ribbon is gone, the one I have got inside maya is a hemoglobin molecule with one color. And when I want to select each alpha or beta-globin, I failed to do so because there sometimes have some polygons from other alpha or beta-globin. Is there a way to solve these problems? >>> >>> 2. I have tried to export the scene to a .wrl file and convert it to maya file via wrl2ma, but when I open the finish converted maya file it always give me lots of error messages like this : >>> "Error: file: C:/Users/**/hemo_ribbon.ma line 116: setAttr: Too much data was provided. The last 173 elements were not used. // " >>> and this :"// Error: file: C:/Users/**/hemo_ribbon.ma line 13078: setAttr: Too much data was provided. The last 1193 elements were not used. // " >>> Is this a problem which happen during the export process of Chimera or some other reasons? >>> >>> Looking forward for your reply >>> Thank you >>> -- >>> With kind regards >>> Ruijie Chen

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some questions about Chimera
by Ruijie Chen 02 Aug '13

02 Aug '13

Dear Sir / Madam: I am a 3D animation student who recently started to making medical animation videos, and I found Chimera is a very usefull tool for building molecules and proteins. However, there are few things that I don't understand: 1. After I import a .dae file which exported from hemoglobin (PDB: 2hhb), I found that the color I have set for each ribbon is gone, the one I have got inside maya is a hemoglobin molecule with one color. And when I want to select each alpha or beta-globin, I failed to do so because there sometimes have some polygons from other alpha or beta-globin. Is there a way to solve these problems? 2. I have tried to export the scene to a .wrl file and convert it to mayafile via wrl2ma, but when I open the finish converted maya file it always give me lots of error messages like this : "Error: file: C:/Users/**/hemo_ribbon.ma line 116: setAttr: Too much data was provided. The last 173 elements were not used. // " and this :"// Error: file: C:/Users/**/hemo_ribbon.ma line 13078: setAttr: Too much data was provided. The last 1193 elements were not used. // " Is this a problem which happen during the export process of Chimera or some other reasons? Looking forward for your reply Thank you -- With kind regards Ruijie Chen

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Re: [Chimera-users] Using Surfnet tool in a per-frame python script
by Elaine Meng 01 Aug '13

01 Aug '13

Hi William, Thanks for your kind words! I'd like to suggest an alternative approach: accumulate occupancy for the ligand over the whole trajectory and then show an isosurface for that occupancy map. You'd have to contour at a low level (e.g. 1 for everywhere the ligand has been during at least 1 frame), but in my mind at least, this produces a nice blob showing everywhere the ligand has been. I don't know how successful it would be on this specific data, but it should be relatively easy to try (no scripting involved). It may depend on how flexible everything is and how much it moves around… you can hold steady based on some set of atoms, but there may still be residual "motion blur." See the "Occupancy Analysis" section of the MD Movie man page: <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/movie/framemovie.…> <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/movie/movie.html#…> You would have to first indicate atoms to "hold steady" (if an appropriate set exists, or maybe your trajectory is already pre-processed to keep the structure in the same place and orientation as possible), select the ligand, and then in the occupancy calculation dialog choose appropriate settings. Sounds like you would turn off (set to false) "limit data collection to within cutoff…" and "collect data separately…", maybe decrease "volume grid spacing" to get a less chunky final result, and adjust anything else as you see fit. As for pruning, you can hide disconnected bits of surface using Hide Dust and/or erase parts of a volume dataset using Volume Eraser (both in menu under Tools… Volume Data). <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/volumeviewer/hide…> <http://www.rbvi.ucsf.edu/chimera/docs/ContributedSoftware/voleraser/voleras…> Just an idea, but maybe worth a try… Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco > First, thank you all for such a wonderful program! Also, thanks to the > users' list for such quick, thorough, and always-helpful answers! > > Second, a little background: I have a gromacs MD simulation (well several, > actually) of a small ligand diffusing through a protein. Because the ligand > requires the entire simulation to traverse the protein cavity, I was > thinking of using the Surfnet tool to accumulate or "build-up" the cavity > interface between the ligand and protein using a per-frame python script a > la Eric's suggestion in the Dec 2009 [Chimera-users] Surfnet command line > thread on this mailing list. I was thinking I could then "prune" the > accumulated SurfaceModel using the surfvol.py script available on the > http://plato.cgl.ucsf.edu/trac/chimera/wiki/Scripts download page.

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Using Surfnet tool in a per-frame python script
by William McDonald 31 Jul '13

31 Jul '13

Dear Chimera Developers, First, thank you all for such a wonderful program! Also, thanks to the users' list for such quick, thorough, and always-helpful answers! Second, a little background: I have a gromacs MD simulation (well several, actually) of a small ligand diffusing through a protein. Because the ligand requires the entire simulation to traverse the protein cavity, I was thinking of using the Surfnet tool to accumulate or "build-up" the cavity interface between the ligand and protein using a per-frame python script a la Eric's suggestion in the Dec 2009 [Chimera-users] Surfnet command line thread on this mailing list. I was thinking I could then "prune" the accumulated SurfaceModel using the surfvol.py script available on the http://plato.cgl.ucsf.edu/trac/chimera/wiki/Scripts download page. Now, I can generate a Surfnet surface easily (as Eric points out) for each MD frame using the python commands from Surfnet import interface_surfnet interface_surfnet("LigandAtoms","ProteinAtoms") But how, if possible, can I combine all the individual SurfaceModels into one surface? Also, and not secondarily, does this seem like a reasonable approach to obtain the ligand-protein cavity surface? Thanks again for all your generous support. -- William J. McDonald Postdoctoral Scholar Department of Chemistry and Biochemistry University of California, Santa Cruz

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