General Problem with Anybody

Hi there,

I started dealing with Anybody just a week ago, hence there are still things which I dont get.
I’d like to delete the legs and the left arm from the “StandingModel” (I know that there is an existing model like this, but I shall do it this way).
How do I start?
I started with deleting the muscles from the feet (therefore I used the mus.any embodied in leg.root.any), but as soon as I delete the ankle joint (Jnt.any embodied in leg.root.any) an error occurs “too few kinematic constraints”.
I really dont get how to release the legs and so…

I’d really appreciate ur help :slight_smile:

Hi,

The solution depends on the repository you are using. With the AMMR1 it is very easy, there is a file called BodyPartSetup.any in each model. As the name says it controls the different parts of the body, just switch On or Off the parts you want.

If you use an older version of the repository you will have to use the body model corresponding (probably TrunkRightArm).

In any case i don’t recomand you to modify directly the body parts in the Body folder. There is a lot references to connect correctly the parts to each other and it is quite complicated.

I have a last remark, if you plan to remove the legs then the StandingModel might not be the best choice as it is set up to connect the feet to the ground, that will cause prblems without feet. You may consider to use the FreePosture model instead which is driven by the pelvis and therefore will give no problems when removing arms or legs.

Best regards, Sylvain.

Hey man!

Thank you for your quick response :slight_smile: As you mentioned the standing model is connected to the “ground”. I attached the fibula to the ground and started removing the feet. Next step would be connecting the femur to the ground and to remove the fibula. But it seems that ain’t the correct way or the appropriate way, respectively.
So, I’ll attempt to embody the SpineShoulderArm.any and use the StandingModel files as a template for the joints and drivers. Do you think this approach will work? Sorry, I’m totally new to Anybody :wink:

My future goal is just having the arm and shoulder displayed with the muscles, which are attached to the trunk, attached to the global referrence.
Hmm, what just popped into my mind is, do I have to remove the trunk or will just not drawing the trunk be sufficient?

Thankx,
Hauke

Btw, I’m using Version 3 :confused: Hopefully V.4 next week :slight_smile:

Hi Hauke,

It is not the good way to remove the segments one by one, i think you have found that out by yourself.

As i said before the easiest way (with version 3) is to use the preexisting body models. From your description of the model youwant you should use the TrunkRightArm body model which only includes the trunk and the right arm. As for the joints driver you should use the ones from the FreePosture model, they allow you to fix the pelvis to the ground and drive all other joint angles individualy.

Please notice that you can’t model the arm alone, the trunk allways need to be there for the muscles atachment. But if you don’t want to display graphicaly the trunk you can simply not draw it, or make it transpaprent.

Best regards, Sylvain.

Hi Sylvain,

well, after I got the hang of it, I managed to build my model quite easily :slight_smile:

Now a problem occurs, when I start my InversyKinematicStudy:

0.0) …Design variables have been updated.
WARNING(OBJ.MCH.KIN6) : C:/D…n/H…s/E…n/H…e/R…2/BRep/A…g/S…e/Interface.any : rot : Close to singular position : Orientation close to Gimbal Lock, i.e., first and third axis of rotation being parallel
WARNING(OBJ.MCH.KIN6) : C:/D…n/H…s/E…n/H…e/R…2/ARep/A…g/SAM/JointsAndDrivers.any : rot : Close to singular position : Orientation close to Gimbal Lock, i.e., first and third axis of rotation being parallel

I don’t know exactly what this means or how I can solve it.

Anyways I want the pelvis linked to the ground fixed, but without having the chance to rotate it. So I try to give the driver in the JointsAndDrivers.any some fixed numbers instead refering to the Mannequin.any…but it aint working. There are some unknowns :frowning:

Is there a chance to get what I want the easy way?!

Hope u understand what Im talking about :wink:

Bonjour!
I’m not the expert here so I refer to wikipedia, http://en.wikipedia.org/wiki/Gimbal_lock
It’s a pretty ok general description of the problem.
I’m sorry to say that I don’t have an immediate solution for you.
Concerning your other problem (“driving” the pelvis), I don’t understand what you mean.
Cordialement,
jokke

Hi Hauke,

As long as the gimbal lock does not really “lock” but is only close to, the model can still run. So usually you can live with it. But if the kinematic really fails the solution is either to modify the motion so the lock does not appears or either to change the rotational type (from RotVector to RotAxisAngles for example).

As for fixing the pelvis to the ground you should use the drivers from the FreePosture model, it has the pelvis fixed to the ground as you want it. For your particular model, i really think the FreePosture is the one you should used as template. This is the easy way, you just have to delete the drivers for the body parts you removed (legs) and it will work nicely.