So I'm working with a small model (a modification of the rat model in the online library), and the forward simulation often has problems running. The original model and paper describes some muscles as lacking tendons, so I put in very small tendon slack lengths or else the simulation won't run. So 2...

So I'm trying to set the default fiber length in the GUI, but I can't seem to access the ActivationFiberLengthMuscle class. I'm new to casting, so maybe I did it wrong... but I also can't access the constructor for that class. Here's a relevant thread, but I can't make sense of it: https://simtk.org...

Is there a way (or is it already there) to implement friction in joints?

Thanks!

Is it possible to do this with a custom joint perhaps? Make a joint for the end-effector(foot) and limit it's movement to a whole plane?

Hi, thanks for your reply. Unfortunately, what I desire is more complicated than this: I want to keep the end effector (the foot) constrained to move in a plane (with some room for error) while all the joints can move as long as it's within their constraints (will use coordinate limiting forces). Do...

Thanks! That completely clears up my confusion.

Just one more question-- I can see how to do this in a C example I found, but what's the method for doing it in the gui scripting, if at all possible?

Thanks again.

I answered my own question, well, at least I got around the problem by creating a controller.

But for future reference: are the default_activation variable and setActivation() method not accessible/available from the gui scripting?

Thanks!

I want to look at the effect of activating different pairs of muscles on the movement of the limbs. I am having a problem with automating this, however. I can get the simulation to run and save a .mot file, but I can't get it to set the activations and actually work (they stay at the default instead...

Hi! I'm having a problem where, in using the forward dynamics tool, the joint angles aren't constrained as they should be and as prescribed in coordinate set range. For example: <Coordinate name="ankle_flx"> <!--Coordinate can describe rotational, translational, or coupled motion. Defaults to rotati...

For complicated reasons not worth explaining, is there a way to restrict the movement of an end effector-- say the foot-- to a certain plane? Basically, I want to test how activation of different muscles contribute to moving the foot in the x-y plane, and thus restricting any movement in the z plane...