simtk.org

I've found that when I scale a model in say version 1.8, I can't open it in version 1.5.5.
I get a message saying "Model_SCALED.osim contains OpenSimDocument, expecting Model". (It does open up again in version 1.8, so it seems to be saving ok.)

Is this intentional, or should I be able to open models in all versions?

Hi Kathleen,

You will not be able to open models from newer versions (like 1.8) in older versions (like 1.5.5). This is due to significant changes to the model file format (i.e., the xml file), as well improvements to the dynamics engine (e.g., the ability to model constraints).

Was there a particular reason why you were trying to use a newer model scaled in older version?

Yes. In version 1.5.5 (and older) if I locked a coordinate, I would get a message saying "Coordinate.setValue: WARN- coordinate subtalar_angle_l is locked. Unable to change its value." And you would get that message just once, and then Scale or IK or whatever task would proceed. Now, I'm getting it hundreds of times and it is slowing things down very significantly.
Also, this sometimes results in

"A java.lang.OutOfMemoryError exception has occurred."

When I run the exact same files in version 1.5.5 (except with the other version of the skeleton) I do not encounter these problems.

Hi Kathleen,

I had a fix for this last week and it will be in the next release that I plan to put out very soon.

-Ayman

Unfortunately, version 1.8 is still in a "beta" or testing version, and this is a bug that we are aware of (and have fixed for the official release). However, if you find any other bugs in v1.8, please add them to the bug list, or bring them up in the forum.

If you are doing research, I recommend sticking with v1.5.5, which is the latest stable release, for now, as you cannot go backwards (but you can go forwards). In other words, you can use v1.5.5 in v1.8 but not vice-versa. We will be officially releasing a stable version of 1.8 in the near future, and when that happens, then migrate to v1.8.

Hi Kathleen,

Version 1.8 is officially out, so you should be able to verify the fix.

Thx,
-Ayman

Yeah i've gotten the some matlab scripts from the developers workshop, however i'm having trouble setting up our lab coordinate system to collect with OpenSim conventions (Fy as vertical coordinate/Fz as medial lateral coordinate). Thanks for the post though!