- Chimera-users - RBVI Mailing Lists

Re: [Chimera-users] Proline sidechain broken (with backbone as a ribbon)?
by Visvaldas K. 24 May '11

24 May '11

I'm very sorry, I take my question back. Actions->Atoms/bonds->Show will do the trick. Vis

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Proline sidechain broken (with backbone as a ribbon)?
by Visvaldas K. 23 May '11

23 May '11

Hi, I really like the default view of a loaded PDB file, where the whole protein is shown as a ribbon, but also the sidechains next to the heterogroups are shown. Proline shows up in this representation as a sort of rhomboid (or kite) shape, which is okay. However, I cannot achieve the same effect for proline when I select proline manually. If I do Actions->Atom/bonds->sidechain/base->show, the proline sidechain appears as a broken rhomboid, which looks more like a hook, i.e. a one of the bonds is missing to close the loop. How do I obtain a "closed" proline sidechain look? Thank you, Vis

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centering a volume to an atom's coordinate
by Roni Rayes 23 May '11

23 May '11

Hi, I am trying to center volumes (cylinders and spheres that I created using spider) to an atom from a pdb file. When I created the volumes I made sure that their center is in the middle of the box containing the volume. I tried to set the coordinate of the volume to the atom's coordinate (in the coordinate tab under volume viewer) but the position of the volume was not centered to the coordinates provided. Any idea on how to do that? Thank you Roni

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PipesAndPlanks
by George Tzotzos 23 May '11

23 May '11

Hi everybody, I'm dealing with a dimeric hexahelical bundle. I've been trying to name the individual helices (e.g. a1, a2, etc) and colour them differently to no avail. Obviously, I'm missing something. Your guidance will be greatly appreciated. Have a good weekend George PS. Sorry if you receive this message for a second time. It was sent from a different address earlier and I'm not sure if it reached the list.

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Pack molecules in Unit Cell
by Joe Osmundson 20 May '11

20 May '11

Hi everyone, I would like to transform a pdb so that it fits nicely in the unit cell, which seems to be described here: http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/unitcell/unitcell.… as "Pack molecules in unit cell". However, this is not an option when I bring up the options in the Unit Cell tool (although literally everything else that should be there IS indeed there). Is there a glitch in the most recent version? Is there an easy way to script this to essentially move the model (and its crystallographic mate) into the center of the unit cell? Thanks, Joe Osmundson Darst Lab Rockefeller University

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Completely reinstall chimera
by Daniel Hitchcock 20 May '11

20 May '11

Hi, I want to completely uninstall chimera and remove all the settings from the program. I notice though if I uninstall and reinstall though, it still has all the settings and history from before. How can I completely remove Chimera from the computer so I can return to default settings? Thank you -daniel

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solid-cylinder representation of helices
by Francesco Pietra 19 May '11

19 May '11

HI: Is any plan about a solid-cylinder representation of protein helices? It would be very useful to represent pathways of ligands inside a protein (in combination with centroid). Helices allow a less defined 3D perspective, especially when all is projected into a screen or paper. Thanks francesco pietra

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Visualising PDB files from AMBER
by George Tzotzos 18 May '11

18 May '11

Hi everybody, I've generated a average pdb structure from an AMBER trajectory. The structure contains one water molecule (named: WAT). I fail to visualise it in Chimera despite the fact that I can select it. I'm using Chimera 1.5.2 on OSX 10.6.7 Any ideas explaining this behaviour? I'm attaching the relevant file. Thank you in advance for your help Best regards George

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Re: [Chimera-users] Pseudobonds disappearing during morphing movie
by Elaine Meng 17 May '11

17 May '11

Hi Alan, Sorry, there isn't currently a command to apply residue class, only scaling (ribscale) and style (ribrepr): <http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/ribbonstyle/ribbon…> Some possibilities: - save session with morph already calculated and residue class applied. Your script would then restore the session, play the trajectory, and record the movie. I agree this is not as nice, since then you are saving two files instead of one, and the session file is large. You wouldn't have to wait for the morph to recalculate, however. - use a small python script to apply the residue class. Your Chimera script could open that python file, which automatically executes it. One of the other developers would have to supply the python (beyond my skill set, sorry), and that also requires having two files, albeit much smaller than a session file. In general when playing a morph with ribbons that show secondary structure, consider whether you need to recalculate the secondary structure assignments with "ksdssp" at each frame. To execute a set of commands at each frame, one would use the "perframe" command in combination with "alias": <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/perframe.html> <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/alias.html> <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/ksdssp.html> For example, your script could contain something like: alias ^redefine ksdssp #2 perframe redefine movie record coordset #2 1,21; wait 21; ~perframe I hadn't used ksdssp/perframe in my examples since (perhaps fortuitously) the secondary structure didn't change that much. If you are just displaying a tube or licorice which doesn't show secondary structure with different widths, it doesn't matter, however. You're right that the shape tube surface will not automatically morph along with the structures, but it might work to destroy/recreate it at each coordinate frame using "perframe". Interesting idea... I haven't tried it, though! I hope this helps, Elaine On May 13, 2011, at 6:10 AM, Alan Cheung wrote: > Thanks Elaine! Yes, the reported thickness was 3.333 (pixels?) and that seems to match the width of the pseudobond i see on the video. The width isn't too bad, and i can live with it. > > Thanks for the explanations and tip too. > > One last question : can I apply a saved residue class (from the ribbon style editor) via a command? I'm morphing a mixture of ribbon and side chain atoms and (for a leucine residue) the CA-CB bond is unrealistically long, but seems ok if i remove the orientation atom (O) from the residue class. I saw the "shape tube" feature in the documentation that draws a tube through CA atoms, but i guessed it's not morphable (and might also not include my precious pseudobond ;) ) > > Many thanks again for the quick replies! > > Alan > > On 12/05/2011 19:22, Elaine Meng wrote: >> Hi Alan, >> Never mind about the PDBs, I made up my own by deleting parts of the structures in my favorite morph test case. >> >> I think I answered all of your issues except for the pseudobonds completely disappearing with "morph movie nogui true" -- I did reproduce that problem, and it seems like a bug, albeit mysterious. I'll file a report about that one, but in the meanwhile I hope you will be able to manage without using that option. >> >> One minor thing is that I generally recommend adding a few more wait frames to the recording after the morph plays, to avoid any "motion blur" effect at the end you might get as a result of encoding. I didn't see much of that effect in my test case proteins using your script, however. It may be because the morph is spread out over 50 frames so there is less differences between adjacent frames, but I was also using different PDBs than you. >> Best, >> Elaine >> >> On May 12, 2011, at 9:25 AM, Elaine Meng wrote: >> >>> Hi Alan, >>> I haven't tried the whole script yet (can you send me the PDB files? I'll keep them private, i.e. only for the development group here if you send them just to me) but will try to address the low-hanging fruit in your set of questions: >>> >>> (A) lines thinner in saved movie. In general, lines such as silhouette edges and pseudobonds may turn out thinner in saved images and movies when you are doing "supersampling," which initially saves a larger image and samples it down to the final requested size. You can check if this is the issue by using File... Save Image to save a single image -- the dialog should report the maximum achievable linewidth given the requested size and amount of supersampling. The reason is that there is an upper limit to how fat your computer can draw the lines (at least via the method used by Chimera). If you have 2x2 supersampling, for example, Chimera will try to make the lines twice as fat in the initial larger image, but may run into this upper limit. Then when the image is sampled down to the final size, the lines may not be as thick as they appear in the interactive display. You could try using lower supersampling. Also make sure you are using a recent version (1.5.3 candida > te ! >>> or 1.6) because there was a lines-too-thin-in-images bug a couple of months ago. >>> >>> (B) setattr "p" vs. "g" -- this is because some attributes are for individual pseudobonds (p) and some attributes are defined for whole pseudobond groups (g). Individual pseudobonds don't have a linewidth attribute, it is set at the group level. All the pseudobonds in that group (for example, hydrogen bonds) would get the same linewidth and it is not possible to make different ones in the same group have different widths. If you are looking at the Selection Inspector or some other attributes inspector, it will show you which attributes are for individual pseudobonds and which are for groups. The balloon help will give the attribute name and allowed values. >>> <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/modelattrib.html> >>> >>> I will try to look at your other issues and get back to you, >>> Elaine >>> ---------- >>> Elaine C. Meng, Ph.D. >>> UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab >>> Department of Pharmaceutical Chemistry >>> University of California, San Francisco >>> >>> On May 12, 2011, at 8:54 AM, Alan Cheung wrote: >>> >>>> Hi there - i'm scripting a complex movie and am having problems with >>>> pseudobonds during morphing. Script is pasted at the end. >>>> >>>> Part of the movie contains a morph between two structures, both of >>>> which are missing the same amino acid segment. Loading the two >>>> structures show the pseudobond for the missing residues and the >>>> resulting morph also contains the same pseudobond. >>>> >>>> I've been changing the thickness of the pseudobond with : >>>> >>>> setattr g lineWidth 8 >>>> >>>> and while the two static structures and the morph in the chimera >>>> window have a thicker pseudobond, the resulting movie (encoded to >>>> .mov) does not. Am i doing something wrong? >>>> >>>> Alan >>>> >>>> p.s. incidentally, when morphing by script, if one includes "nogui >>>> true" with the "morph movie" command, pseudobonds aren't kept in the >>>> morph at all. A bug? >>>> p.p.s. can someone explain to me the difference between "setattr g" >>>> and "setattr p"? I've read the manual but i don't understand why only >>>> the former seems to work for me. >>>> >>>> ## movie script >>>> >>>> open model1.pdb >>>> open model2.pdb >>>> morph start #0 frames 50 name morph1 method linear >>>> morph interpolate #1 name morph1 >>>> morph movie name morph1 >>>> coordset #2 1,1 >>>> setattr g lineWidth 8 >>>> ~modeldisplay # >>>> >>>> movie record supersample 3 directory ~/TEMP/ >>>> modeldisplay #2 >>>> coordset #2 1,51 ; wait 51 >>>> movie stop >>>> movie encode output morph1.mov >>> >>> >>> _______________________________________________ >>> Chimera-users mailing list >>> Chimera-users(a)cgl.ucsf.edu >>> http://plato.cgl.ucsf.edu/mailman/listinfo/chimera-users >> >> > > -- > Alan Cheung > Gene Center > Ludwig-Maximilians-University > Feodor-Lynen-Str. 25 > 81377 Munich > Germany > Phone: +49-89-2180-76845 > Fax: +49-89-2180-76999 > E-mail: cheung(a)lmb.uni-muenchen.de

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labeling residues
by Daniel Gurnon 16 May '11

16 May '11

Hi all, A student of mine wants to make a wire sculpture of a protein, and I'm thinking of ways Chimera could make the task easier. Ideally, I would create a script that would display any protein in wire-form, with residue positions clearly and unobtrusively labeled. I'd like to use the command line to display a backbone as a licorice ribbon with residue numbers and 1-letter codes at the alpha carbon of each residue. so starting out, I would use: ribscale licorice; ribbackbone; rlabel @ca; But instead of "ALA 24.B", I want "A 24". Though I can get what I want using the Actions menu, I can't find a way to create custom rlabels via the command line. Is there a way to do this? If possible, I would also like to position each label near the spot on the ribbon closest to the alpha carbon (the "primary atom"). I can see how to do this with the molecule attributes panel, but I'm having difficulty setting the placement through the command line. And while I'm at it...is there a way to color a spot on the ribbon closest to the alpha carbon a different color than the rest of the ribbon? Thanks for the help! Dan -- ____________________________ Daniel Gurnon, Ph. D. Associate Professor of Chemistry DePauw University Greencastle, IN 46135 p: 765-658-6279 e: danielgurnon(a)depauw.edu

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Can eraser position be defined by coordinates?
by Kelly Dryden 16 May '11

16 May '11

Hi, I would like to place the origin of the eraser to correspond with the center of my map but haven't found a way to define its position based on coordinates, only by moving it with the mouse. Is there a line command or other menu option that allows me to set the position more precisely? Thanks, Kelly

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rigid body rotation of subunit
by Dhiraj Srivastava 13 May '11

13 May '11

Hi I have the structure of two homologous protein. These proteins are dimeric. when I am superimposing chain A of one protein on to the chain A of other, it looks like chain B of one protein is related to chain B of other protein by rigid body rotation. How can I calculate the angle of rotation in chimera? Is there any way, I can draw a vector along beta sheet? Thank you. Dhiraj

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shape factor
by maznar 13 May '11

13 May '11

Hello, We are using Chimera to classify viruses. We use pdb files from viper. We want a way to obtain exactly shape factor and/or compare with an icosahedron. We have problem do it. We open pdb file, draw icosahedron using "hkcage" (all models actives) and try to compare that two figures using "fit in map", or similar but doesn't work. What is the best and exactly way to do it? Thank you.

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square of density volume
by 仁田亮 12 May '11

12 May '11

Hi chimera users, I want to calculate the square value for the volume of the electron density because I want to calculate the variance map. Do anyone know whether we can calculate the square value of the volume by chimera? And if we can, could you teach me how to calculate? Thanks for your time and help, Ryo

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Pseudobonds disappearing during morphing movie
by Alan Cheung 12 May '11

12 May '11

Hi there - i'm scripting a complex movie and am having problems with pseudobonds during morphing. Script is pasted at the end. Part of the movie contains a morph between two structures, both of which are missing the same amino acid segment. Loading the two structures show the pseudobond for the missing residues and the resulting morph also contains the same pseudobond. I've been changing the thickness of the pseudobond with : setattr g lineWidth 8 and while the two static structures and the morph in the chimera window have a thicker pseudobond, the resulting movie (encoded to .mov) does not. Am i doing something wrong? Alan p.s. incidentally, when morphing by script, if one includes "nogui true" with the "morph movie" command, pseudobonds aren't kept in the morph at all. A bug? p.p.s. can someone explain to me the difference between "setattr g" and "setattr p"? I've read the manual but i don't understand why only the former seems to work for me. ## movie script open model1.pdb open model2.pdb morph start #0 frames 50 name morph1 method linear morph interpolate #1 name morph1 morph movie name morph1 coordset #2 1,1 setattr g lineWidth 8 ~modeldisplay # movie record supersample 3 directory ~/TEMP/ modeldisplay #2 coordset #2 1,51 ; wait 51 movie stop movie encode output morph1.mov

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How to show an icosahedral cage
by Tom Goddard 11 May '11

11 May '11

Hi Yen-Chywan, The Chimera "hkcage" command makes a cage of pentagons and hexagons to show virus symmetry. For example, open emdbID:1058 hkcage 1 1 radius 170 orient 222r linewidth 4 color blue The hkcage command has options for the lattice parameters for your virus, its radius, what icosahedral coordinate system is being used. Here's the documentation. http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/hkcage.html http://www.cgl.ucsf.edu/chimera/tutorials/volumetour/volumetour.html#icosca… The meshmol command can make the edges of the cage cylinders instead of lines. http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/meshmol.html The HHMI virus viewer Chimera tool is not part of the standard Chimera distribution. It was made for a CD distributed by the Howard Hughes Medical Institute http://wwwtest.cgl.ucsf.edu/Outreach/ViralOutbreak/index.html http://www.hhmi.org/catalog/main?action=product&itemId=366 We don't distribute it separately. Tom > Dear Tom, > > I attend Scripps cryoEM workshop before and meet you there. > > Attach please find a screen capture of a virus. But there is a > icosahedra cage. My question is how to display that cage with my virus > volume? > > I did find it in HHMI virus viewer demo movie. But where can download > this viewer? > > Thanks > > Yen-Chywan >

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constructing a dimer
by uzma saqib 11 May '11

11 May '11

Hello, I want to totally freeze the movement of one protein (which is a homology model) and open another molecule of the same protein, which I want to keep movable, so that I can make a dimer out of this at my chosen place on the first protein molecule. Plz help . thanks uzma

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System Compatiblility
by Satterlee, James D 11 May '11

11 May '11

Hello, I've not yet downloaded or used Chimera, but I am contemplating it. I am looking for Windows System compatibility information for the various newer versions of Chimera. To me it wasn't obvious on the Chimera home site. I do not use Window's 7 and I'm wondering which version might be most trouble-free for a Windows XP version with all service packs installed. Thanks, Jim Satterlee James D. Satterlee Professor of Chemistry Washington State University Pullman, WA 99164-4630 hemeteam(a)wsu.edu 509.335.8620

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color side chain only
by Zhou, Ming (NIH/NCI) [C] 11 May '11

11 May '11

Hello, this is Ming Zhou at NCI-Frederick, Maryland. I am trying to use Chimera to make some ribbon structure figures. I am wondering how I can display only side chain (without backbone) for a specific residue. Usually, if I display the residue, select the residue at the Atom specifier and color it. The color would be partially on the ribbon structure too since the backbone of that residue is on the ribbon. How do I avoid coloring backbone, only color the side chain? Thank you very much. Ming

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Morphing volumes
by Burgoyne, Thomas 10 May '11

10 May '11

Hi, I have two 3D-EM volumes that I wish to use the morph option for. I can align the two maps in chimera by hand so that they sit well together but the problem is I want to be able to create a morph video from the maps new positions. When I use the morph option it only allows me to create a morph from the original set starting positions of each volume. Is there a way to get around this? I would be very thankful for any help or guidance. Tom

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Re: [Chimera-users] building large size polymer
by 윤홍민 05 May '11

05 May '11

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Re: [Chimera-users] imgCIF files
by Tom Goddard 04 May '11

04 May '11

HI Mattia, Chimera can save MRC2000 format which is nearly identical to CCP4 format. Any software that reads CCP4 will likely read the MRC output from Chimera as CCP4, but the origin of the map is specified differently. The MRC format allows a floating point origin specification which is not part of the CCP4 format and Chimera uses that. So alignment of the Chimera written MRC and atomic models may not work right in other software. A basic problem with CCP4 is that the origin has to lie on a crystallographic lattice point, which isn't so good for electron microscopy or maps from non-crystal sources. Chimera doesn't know about a SAXS bead radius in PDB header remarks. Also Chimera may try some heuristics to connect up the beads as if they were actual atoms. You'll have to try and see. You can adjust the sphere radius for the beads by selecting them and using Selection Inspector (green button in lower right of main Chimera window) or a command setattr a radius 5 #0 For making a simulated map with the Chimera "molmap" command the atom radius is not used. It simply adds 3-dimensional Gaussians centered at each atom. The Gaussian width is calculated by the resolution value used in the molmap command molmap #0 8 See the documentation for details. http://www.cgl.ucsf.edu/chimera/current/docs/UsersGuide/midas/molmap.html Tom > > Dear Elaine, > > thanks for your very fast and informative answer! I missed that option > in the list of Chimera commands. I will try it out tomorrow (I'm at > home now...). Perhaps it would be nice to add it to one of the > pull-down menus (in the Volume options?). Is there a way then to save > the map, say in ccp4 format? > > As for the SAXS file, yes, for instance the DAMMIN/DAMMIF-generated > files are in PDB format. But will Chimera read in the correct radius > for the beads, which is stored in the file header? (or is there a way > to externally enter the radius?). > > Thanks again - Mattia > > At 09.32 04/05/2011 -0700, Elaine Meng wrote: >> Dear Mattia, >> You can make a density map from atomic structures (or their parts) in >> Chimera using the "molmap" command: >> >> <http://www.cgl.ucsf.edu/chimera/docs/UsersGuide/midas/molmap.html> >> >> For example, commands: >> >> open 2gbp >> molmap ligand 4.5 >> molmap protein 5 >> >> ... would make a map of resolution 4.5 for the ligand part of the >> structure (glucose) and another map of resolution 5 for the protein >> part of the structure. You could also specify the whole structure, >> particular chains, etc. >> >> If the SAXS model was in the form of a PDB file with the beads as >> "atoms," perhaps you could use a similar procedure. >> >> I hope this helps, >> Elaine >> ----- >> Elaine C. Meng, Ph.D. >> UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab >> Department of Pharmaceutical Chemistry >> University of California, San Francisco >> >> On May 4, 2011, at 7:44 AM, Mattia Rocco wrote: >> > >> > To the developers of Chimera: is there any intention of implementing >> the uploading of imgCIF density maps files? Such files can be >> generated by RasMol starting from either atomic structures or >> low-resolution bead models (e.g. SAXS-derived models). >> > >> > Conversely, it would be nice if density maps could be generated >> within Chimera... >> > >> > Best - Mattia >> > >

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solvent exposed charged resides
by George Feldman 04 May '11

04 May '11

Hello Chimera community, I am rather new to Chimera, but in general familiar with PyMol. I switched to Chimera for the added functionality and general "free-ness," and so far I like it, but I'm having difficulty getting started. What I really need to do is identify the solvent exposed (SAS) residues that are charged. In particular I would like to identify exposed lysines, arginines, glutamic acids, and aspartic acids. All I need to do is identify and count them, is there a way to do this without slowly going over the entire molecular surface? Please bear in mind that I am capable of typing in commands, but I am no programmer. If it is too complex, I will simply, and sadly, have to do it manually. My fear with the manual approach is that I will miss something or miss-classify it. Your advise and help is greatly appreciated. PS. I've tried to do Render by Attribute -> areaSAS, but that doesn't seem to be working for me even after I tell it to calculate the surface. I'm not sure what I'm doing wrong if this is the approach that I am supposed to be taking. Best regards, George

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imgCIF files
by Mattia Rocco 04 May '11

04 May '11

To the developers of Chimera: is there any intention of implementing the uploading of imgCIF density maps files? Such files can be generated by RasMol starting from either atomic structures or low-resolution bead models (e.g. SAXS-derived models). Conversely, it would be nice if density maps could be generated within Chimera... Best - Mattia Dr. Mattia Rocco Biopolimeri e Proteomica Istituto Nazionale per la Ricerca sul Cancro (IST) c/o Centro per le Biotecnologie Avanzate (CBA) IST c/o CBA, Largo Rosanna Benzi 10 I-16132 Genova, Italy Phone: +39-0105737-310 Fax: +39-0105737-325 e-mail: mattia.rocco(a)istge.it ATTENZIONE. Il presente messaggio ed i suoi allegati devono intendersi ad uso esclusivo dei suoi destinatari e sono confidenziali. Persone diverse dal destinatario, anche ai sensi del D.Lgs. n. 196/2003 , non debbono prendere visione dei contenuti, copiare od inoltrare l'e-mail a terzi. Se ricevete questo messaggio per errore, Vi preghiamo di cancellarlo, di distruggerne ogni copia e di informarci immediatamente. La mail non è un protocollo sicuro, pertanto IST declina ogni responsabilità in caso di intercettazione o modifiche del presente messaggio. WARNING. This message and any attachments is intended solely for the use of the intended addressees and is confidential. Any unauthorized review, use, disclosure or distribution is prohibited. If you receive this message in error, please delete it, destroy all copies and immediately notify us. Mail is not a secure protocol, therefore IST will not be liable for interception or amendment of this message.

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pause during morph conformations
by Charles Greenberg 04 May '11

04 May '11

I have a 3-state structure and I'm currently using morph conformations to interpolate between them. This works very nicely, but I'd like the output movie to pause for half a second (a few frames) during each of the three key states. Anyone know how to do this? I know you can add behaviors during particular frames, but I don't know how to make it pause. Thanks! --Charles

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