AboutDownloadsDocumentsForumsSource CodeIssuesNews

Release Name: OpenSim 2.4

Release Notes
New Functionality
1. The quality of results of CMC in 2.4 matches or exceeds results from 1.9.1.  
2. Faster and more robust tools for performing inverse kinematics and inverse dynamics.  
3. More flexible format for applying external loads to a model.  
4. Tighter integration of OpenSim and the underlying SimTK/Simbody computation layer and 
upgrade to Simbody 2.2.  
5. RRA and CMC no longer require control constraints.
6. Ability to report model marker locations resulting from your inverse kinematics solution.
7. Ability to add a RigidTendonMuscle to your model.
8. ModelComponent API for adding states and cache variables.
9. ModelControls API for setting controls on a model.  
10. Streamlined definition of muscle models.  
11. Ability to report induced constraint reaction forces from an induced accelerations 
12. The Residual Reduction Algorithm (RRA) is now a separate tool in the GUI with a 
13. Ability to show the XML representation of "Available Objects" that can be used to extend  
models or define setup files (in the latest format of the software).  
14. Editing muscle excitations with the Excitation Editor is easier due to several usability 
15. Convert tool to update setup, model, and storage files generated in earlier versions of 
to the latest version.  
16. Ability to display the center of mass of the model and individual bodies.  
17. Ligaments and springs now have a visual representation in the GUI. 
18. The JointReaction analysis is augmented to also report the location of the internal joint 
and moment.  

1. We have updated the User’s Guide, Developer’s Guide, and tutorials to be compatible with 
OpenSim 2.4
2. Chapter 22 of the User’s Guide describes how to conduct an induced acceleration analysis. 
3. We have added a chapter to the Developer’s Guide that describes how to get started as an 
OpenSim API user.
4. Chapter 16 of the User’s Guide now documents how to use the new, flexible tool for 
associating external forces with a model. 
5. A simple model of the lower extremity and step-by-step guide to help you gain hands-on 
experience with the OpenSim simulation pipeline.  
6. A new API example for adding a Force as a plugin.  

Change Log
Known Issues:
- Installation on machines with non-English locale AND with older OpenSim installs may run 
into visualization issue (red-ball).
- Permissions: Make sure you install OpenSim in a folder where you
have write permissions.

Bug Fixes:
- Several problems were fixed with the elastic foundation model in the case where both 
contacting objects are meshes. 
- A bug in internal coordinate joint (mobilizer) reactions torques was corrected in the 
underlying Simbody dynamics engine.  

Bug 1454: Hookup Passive Force Curve property for Schutte muscle model
Bug 1446: Fix crash restoring marker in Marker Editor
Bug 1432: RRA Adds muscle analysis unnecessarily
Bug 1431: GUI mishandling of old SO actuator files
Bug 1430: Saving settings for CMC in GUI turns on adjust kinematics
Bug 1411: IK Tool not reading final time properly
Bug 1258: Radians and Degrees confusion /mot and sto files confusion
Bug 1172: Forward Tool requiring initial states