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I have develop a model for both OpenSim 1.9 and 2.0
However, when I load the model in the two versions of Opensim. The relative vertical distance between the human and the ground are different. After scaling, , the human is standing on the stair in OpenSim 1.9. However, he seems standing in the air in OpenSim 2.0.

So does opensim 1.9 and 2.0 has different strategy in handing the scaling.

Hi Kang,

In theory they shouldn't be different but I don't know your specific settings. In some earlier version we used to load the static trial after scaling but we don't anymore.

The bottom line is does scaling the same model using same setup/data files produce the same or different models?. You can just save the scaled model in 1.9, open it in 2.0 and save it again (since the file format has changed a bit) and then diff vs. the scaled model created in 2.0.

Please let us know what you find.
-Ayman

Hi Ayman,

Thank you for your reply. In fact, I find that it also occurs before scaling. I creat a stair.vtp by myself and use it as the ground rather than treadmill.vtp for the model 2392. I open the model in 1.9.1. The human is standing on the bottom of the stair. I cannot update the model in opensim 2.0. I create a same model in opensim 2.0.1 and find that the bottom of the stair is around the pelvis of the human.
I am going to check if that is true for the 2354 model. But if so, should I report it as a bug?

Dear Ayman,

I double check it. It seems that the model 2392 has been changed in the two versions. For the example model 2354 in version 1.9, I can open them in both versions. The human stands on the bottom of the stair in both cases.
But for the model 2392, the story is different. In opensim 2.0.1, I cannot open the example model 2392 from the version 1.9. I open the example model 2392 from the version 2.0.1 and find that either the treadmill or the stair is around the pelvis of the human.

The model 2392 must be changed somehow in the two versions.

Thank you.

Kang

Kang,

If the only difference between the models is that their configuration (coordinate values) are different then this is not a bug since we never promise anything about the configuration and you can set the coordinates yourself as needed. IF there are real differences underneath then this is really a bug worth investigation. That's why I suggested you diff the files rather than look at the visuals.

Hope this helps,
-Ayman