- Chimera-users - RBVI Mailing Lists

Ribbon path smoothing
by Jakob Toudahl Nielsen 28 Feb '06

28 Feb '06

Dear Chimera users, I trying to create a ribbon model drawing of a DNA structure containting several abrupt chain-reversals in the DNA-backbone. By default the ribbon path is smoothed over five successive residues. This resuls in the ribbon path supressing the chain-reversals by oversmoothing the path. Is there any way to overide the default value of the FIVE succesive residues to a smaller number (e.g. TWO). Regards, Jakob Jakob Toudahl Nielsen Dep. of Chemistry University of Southern Denmark

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Making a new covalent bond
by Goel, Manisha 27 Feb '06

27 Feb '06

Hi, I have often come across detailed answers from chimera group for a variety of modelling problems on pdb-l or bioinformatics mailing lists. My problem should relatively easy to solve except that I havn't been able to figure it out myslef on chimera. I just need to make a covalent bond between a sugar molecule and an aminoacid (aa-COOH + sugar-OH --> H2O + aa-sugar). Is there an easy way of doing this manipulation in Chimera ? Please advice ? Thanks a lot for your time and effort. -Manisha Goel Post-doc associate Bioinformatics Lab Stowers Institute for Medical Research Kansas city-66210

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chimera vrml issues...
by Thomas Goddard 27 Feb '06

27 Feb '06

------- Start of forwarded message ------- Date: Thu, 16 Feb 2006 23:47:38 -0800 From: Janet Iwasa <jiwasa(a)gmail.com> To: Thomas Goddard <goddard(a)cgl.ucsf.edu> Subject: chimera vrml issues... Hi Tom, I was trying out some of those new scene export functions in Chimera that you showed me a while back, and I've been running into some issues. I've got a large ribbon structure that I wanted to export as VRML, but Chimera only wrote a small file that couldn't be opened. Using notepad, all the file included was the following: #VRML V2.0 utf8 Transform { children [ ] } Saving as a X3d file seemed to work (seemed like a reasonable size at 10 MB) but I couldn't use the translator (X3dToVrml97.xslt) to change to VRML since it appeared to run into memory issues. Trying to save as POV or Renderman either failed or crashed Chimera. Any suggestions? Janet ------- End of forwarded message -------

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question
by Stefano Ciurli 23 Feb '06

23 Feb '06

Hello, I am a new user of Chimera and I need to ask a question: let's say that I am loading several PDB files from the RCSB, all of them belonging to the same protein, the latter having 3 subunits A, B, and C. I need a way to operate on single PDB files (select and manipulate features of each PDB file at once). How do I do it? I can easily find the select->chain option, but it would operate on all chains of that type in all PDB files. Regards, Stefano

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Re: [Chimera-users] chimera vrml issues...
by Greg Couch 23 Feb '06

23 Feb '06

Forgot to cc the list. So to summarize: There some major bugs fixed with the X3D ribbon output in chimera version 1.2180 that affected the Renderman and POV-ray output as well. So please upgrade your chimera. I think I have fixed all of the problems, so if it still fails, please submit a bug report (ideally with enough data to reproduce the problem). As for vrml output, the xslt technology is slow, but works. In the X3dToVrml97.xslt file, it suggests using saxon.sourceforge.net's java-based converter, and I second that recommendation (it was the fastest of the alternatives I tested). Even when the X3dToVrml97.xslt method works, it has problems -- it outputs VRML 3.0 and most VRML importers expect VRML97 aka VRML 2.0. This is especially problematic for ribbons because ribbons use triangle strips for their geometry and 3.0 supports triangle strips while 2.0 doesn't. VRML97 doesn't support translucent colors either. Consequently, I have put improving the VRML output on my list of things to do. And if you have the option of using the Renderman output, use it, because it reproduces what you see in the chimera window the best of the various export formats. Greg Couch UCSF Computer Graphics Lab

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chimera vrml issues...
by Thomas Goddard 23 Feb '06

23 Feb '06

Janet Iwasa reports problems exporting ribbons and nucleotide renderings as x3d, problems converting x3d to vrml, and problems with POV and Renderman output. Tom ------- Start of forwarded message ------- Date: Wed, 22 Feb 2006 17:49:33 -0800 From: "Janet Iwasa" <jiwasa(a)gmail.com> To: "Thomas Goddard" <goddard(a)cgl.ucsf.edu> Subject: Re: chimera vrml issues... Hi Tom, Unfortunately, I still ran into a bunch of problems. The structure I had was a bunch of ribbons with some colored sphere residues. When I exported the scene as x3d and used the vrml converter (which did work but took forever on my home computer) it only appeared to export the sphere surfaces, not the ribbon. I ended up using a different program (called 'ribbons' - I think I talked to you about it before) to make a vrml of the ribbon structure. Then I took the colored spheres and superimposed it over the ribbon in Maya. It was pretty time consuming, but worked in the end. The structure (which was a nucleosome) also had some nice DNA representations using the depiction > nucleotide option, and those didn't seem to get exported to x3d either (could have been a problem with the x3d -> vrml conversion -- hard for me to tell where things went wrong). So I used multiscale models and exported the DNA as VRML that way, which worked perfectly, as always. I haven't tested it to see whether the x3d export only works with spheres or what. It took the better part of an hour to convert from x3d to vrml (and this for only 20 or so residues!), so I would love to find a better solution... Ideas? I think I'm pretty much done with that project for the time being, but it would be really nice to have the scene export stuff working. Any clue about what's up with the pov and renderman formats? Those may be easier to find converters for. thanks! Hope you're doing well, Janet ------- End of forwarded message -------

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Re: [Chimera-users] Chimera on Intel macs
by Eric Pettersen 19 Feb '06

19 Feb '06

Having received no major bug reports for the 1.2199 release candidate, we are promoting it to production release status. We have figured out how to make a combined release for Mac Intel and PPC, 10.3 and 10.4, so the download page is a little shorter. :-) --Eric

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Re: [Chimera-users] chimera vrml issues...
by Thomas Goddard 17 Feb '06

17 Feb '06

Hi Janet, The Chimera VRML export only exports surfaces (molecular surfaces, volume data surfaces, multiscale model surfaces). It does not export ribbons or atomic models. Some text in the Export Scene dialog describes this limitation when you select VRML as the File Type. The X3D export is probably the best option. It is a pain to convert but I would try the X3dToVrml97.xslt translator on a machine with more memory if you think that is the reason it is not working. If you don't have a machine available, we can try on one of our machines. Greg Couch here will need to look at the POV and Renderman failures. Tom

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Chimera 1.2176: surfaces fail for some structures?
by Anna Feldman-Salit 13 Feb '06

13 Feb '06

Hello, I have noticed that for 1.2199 version there is a "know bug" of surface failure. We have been working with 1.2176 version (which is probably even not release version). Apparently, I have the same problem with some of molecules (working with 1.2176). Is it occasionally or there is a "known bug" for 1.2176 too? Can you maybe recommend some version that has not such a problem? Thank you in advance! Sincerely, Anna.

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Chimera on Intel macs
by Eric Pettersen 10 Feb '06

10 Feb '06

The 1.2199 release candidate was compiled for PPC macs and fails on Intel macs despite Apple's emulation software. We are working on compiling natively for Intel macs and will send another mail when an Intel version is available. --Eric Eric Pettersen UCSF Computer Graphics Lab pett(a)cgl.ucsf.edu http://www.cgl.ucsf.edu

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