> When you have the data from the motion capture system it is certain
> that due to skin motion, wobbly masses etc. that the marker drivers
> will be in conflict with each other, if you use all the dof. The
> relative motion between the markers on the same segment will be much
> higher than the tolerances set by the kinematic solver.
Ah…ok. I get it. Thanks.
> So the next step is to remove the rotational driver you added on the
> spine, and replace this with marker drivers, like on the legs.
I need to back up a step. I haven’t yet put a driver on the spine. I assume
what you mean is to do the following:
> 2. You then need to add drivers for the spine motion. Since the
> model automatically make use of a spine rhythm there is three
> rotational dof left free which should somehow be driven. These free
> dof in the spine are the rotations between pelvis and thorax.
> Initial as the first estimation you may copy the driver named
> PostureDriver from the JointsAndDrivers.any file in the
> StandingModel. This will make the spine stiff, but once this is
> running you may release one dof at the time and add more realistic
> drivers, using marker data.
OK. I copied the following from the standing model JointsAndDrivers.any file
into the Gait3D JointsAndDrivers.any file:
AnyKinEqSimpleDriver PostureDriver ={
AnyKinMeasureOrg &Ref2
= …HumanModel.Interface.Trunk.PelvisThoraxLateralBending;
AnyKinMeasureOrg &Ref3
= …HumanModel.Interface.Trunk.PelvisThoraxRotation;
AnyKinMeasureOrg &Ref1 = ...HumanModel.Interface.Trunk.PelvisThoraxFlexion;
DriverPos = pi/180*{
.JntPos.PelvisThoraxLateralBending,
.JntPos.PelvisThoraxRotation,
.JntPos.PelvisThoraxFlexionExtension
};
// This is static posture, so all velocities are zero.
DriverVel = pi/180*{
0.0,
0.0,
0.0
};
Reaction.Type = {
0.0,
0.0,
0.0
};
};
and I got the following error:
ERROR : C:\Grad school\AnyBody\AnyBodyRepository5\Repository.5
\ARep\Toronto\Gait3D\JointsAndDrivers.any(81) : JntPos : Unresolved
object.
Deleting last loaded model…
Model loading skipped
I’m copying the files to the yahoo group “files” section
Thanks for your help,
Tilak
PS. Once we relsolve this, my next question will be if C7 coordinates can be
used to drive the rotational degrees of freedom. (C7 x,y,z won’t give any info
about twisting, of the thorax) Will I need coords for say, both shoulders
instead?
> So the next step is to remove the rotational driver you added on the
> spine, and replace this with marker drivers, like on the legs. When
> you do this, it is a good idea to remove the driver for one
> rotational dof. at the time, and add one marker driver. This will
> make it easier to see the effect of your changes. In the posture
> driver you may add a MeasureOrganizer line to control which dof of
> the rotational measure you are driving.
>
> There is no point yet for C7 so your are right that this has to be
> added to the model.
> There is no point yet for C7 so your are right that this has to be
> added to the model. Please add the node in the following file
> MarkerPosOnBody.any, simply add a AnyRefNode there.