Thanks Tom. I'll try making some demos. From the ones I've seen, rewinding the demo is more like "reset", i.e., any motion won't be reversed but instead the model(s) will be reset to their position and rendering from the previous step. But it should provide much of what I need. Over the past few months, I've been learning Autodesk Maya and talking with Gael McGill and some of the others out there that do molecular animation. While I think animation software like Maya can be a very powerful teaching tool (especially when you need to model things for which there is no 3D data set), the finished movies lack interactivity. Ideally I want modules that automate some of the learning experience (fetching a structure, rendering to highlight appropriate features, taking the viewer on a fly-by tour of the system) while also leaving the participant free to pause and explore the scene on their own. The demos in Chimera are pretty close to what I want actually, but there are a few things I'd change if I could...motion rewinding is one, but it would also be useful to add buttons enabling the user to change rendering options at each demo stop-point without the risk of screwing up the rest of the demo. It would also be nice to instantly reset the demo to the current point if you made a change you want to undo. In a nutshell, I want to design modules that any student or any teacher could use with minimal time invested in learning Chimera. I really think Chimera has a lot of potential for teaching, but the learning curve associated with the program makes it tough for the inexperienced to get the most out of the Chimera's interactive capabilities. Do you think it would be feasible (and a good idea) for me to team up with some computer scientists at my school and work on retooling the demo editor with the goal of designing several student-friendly, interactive modules? I have a lot of experience with teaching, but none with programming, so I know what I want...I just don't know if it's possible. Any advice you can offer is much appreciated! Dan
Hi Daniel, The demo capability in Chimera is designed to do what you want including rewind. http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/demos/demos.html It doesn't allow pausing in the middle of a motion -- only between panels (maybe between individual commands associated with a panel - not sure). But the idea is that the duration of motion in each panel would be short. We haven't made many demos and this tool may be pretty rough around the edges. The trouble with the pause command or Shift-Escape to pause/resume a script is that the fly command returns immediately after you invoke it. It sets up playing the motion which then happens after the command returns. Normally that motion could be halted with the command "freeze". This works with other motion commands "reset", "roll", "move", and it should work with "fly" but doesn't yet work for "fly". In any case, it simply terminates the motion and there is no way to restart it, so that won't do what you want. There is no mechanism to pause the playback in these motion commands, though maybe "pause" and the Shift-Escape key should be made to do that. Currently those mechanisms just block running of additional commands I believe. I wonder whether pause/resume would be adequate for teaching purposes. Seems very likely to me that you will need rewind. By the time a student asks a question the motion is already past the relevant section. We don't have any rewind capability in the motion commands or in general scripts, only the demo tool, and even there I think can be tricky to make it work. Tom -------- Original Message -------- Subject: [Chimera-users] pause during a fly-by? From: Daniel Gurnon To: chimera-users@cgl.ucsf.edu Date: 8/21/09 5:52 PMHi all, I've been considering ways to use Chimera in the classes I teach, and I love the potential of the "fly"command for smoothly navigating between preset positions. But is it possible to pause in mid-flight? The pause command hasn't worked for me here. What I'm really looking for is a way to automate some features of a presentation (e.g., the camera position) while retaining interactivity. Making a quicktime movie is less than ideal, because although I could pause the movie if a question is asked, I couldn't, for example, use a clipping plane to strip away a surface to show an underlying backbone, and then smoothly resume the camera flight. Perhaps I should consider making a demo instead, where pauses are built in? Thanks Dan ____________________________ Daniel Gurnon, Ph. D. Assistant Professor of Chemistry DePauw University Greencastle, IN 46135