• faq

OpenSim F.A.Q.

Platform Requirements

OpenSim currently runs on both Windows and Linux platforms. The GUI has been primarily tested on Windows only. Any machine running windows with WindowsXP SP2 should be able to run OpenSim. Distribution of OpenSim 1.0 has been limited to windows platform.

Issues

• Q. I installed the application but when I launch it I get "Required library failed to load. Check that the dynamic library osimJavaJNI is in your PATH". What could be wrong?

• A. You likely picked not to add OpenSim to your PATH while doing installation. If this is the case you can fix it by either reinstalling or adding the directory where you installed OpenSim to your PATH Environment variable. To check if OpenSim is already in the PATH, open a command prompt shell on windows and type C:\>echo %PATH% You should see the installation-directory/bin in the list of directories.

• Q. I installed the application but when I launch it I don't see the SimTrack options under Tools, what could be wrong?

• A. You likely have an earlier installation of OpenSim that had these modules disabled. To clean all this history info. find a directory with the name ".opensim" (likely under "C:\Documents and Settings\$your_user_name\Application Data") and delete it, then relaunch the application.

• Q. I imported a model from SIMM but the bones don't show up what's wrong?

• A. You likely are missing the bone files that go with your model, try reimporting with the bones located in a directory under your .jnt file.

• Q. How do I tell OpenSim where to locate the bone/geometry files.

• A. Open Edit/Preferences and edit the entry for "Geometry Path" which is a semicolon separated list of directories and add the path you want to it.

• Q. What are .vtp files?

• A. These are the geometry files corresponding to the bones and other objects used by your model. The "vtp" format is a format used by VTK which is the component used by OpenSim for visualization.

• Q. OpenSim loads many models in the same graphics window, how do I know which one I'm working on now?

• A. Although many models are loaded, only a single model can be marked as "Current". This is indicated by the dropdown in the application toolbar and also in the navigator.

• Q. I can't pick some objects in the Graphics window, is this a bug?

• A. Picking is restricted to "Current model" (by default non-current models are dimmed out). If you want to pick on a non-current model you'll have to make it current first.

• Q. I can't pick some MusclePoints in the Graphics window why?

• A. Moving Muscle Points are special Muscle Points that have Splines describing their trajectories so they can't be picked and dragged from the GUI.

• Q. How can I import data into OpenSim Plotter?

• A. Under Y-Quantity, select "Load file..." and then you can read data files on the format of SIMM motion data.

• Q. How about exporting the data for the plots into a ASCII file for processing by Matlab or use in Excel?

• A. Under the "curves list", right click on the top level node and select "Export Data...". OpenSim will prompt you for a file name to save the data into. This file can be later re-imported into OpenSim or used by other applications.