Marker Locations

Hi,

I have a question about marker locations. We are using the
standard “plug-in gait” marker set. Is there any documentation on how
we can refer to the marker locations if using the full body model?

(I see in the gait3d application, they have given most of the marker
locations, but I don’t have any numbers for the upper body points.)

Thanks,
Tilak

Hello Tilak and welcome to the group.

There are currently no markers defined on the upper body of the full
body model in the repository. But you can add marker points anywhere
on the model you like. For each marker you need to know the segment
(bone) it attaches to and preferably a location on the bone defined
as a bony landmark.

Many points (AnyRefNode) are already defined on the bones, and you
can most likely find either the one you are looking for or one close
by if you load the model in and browse through the tree. If you are
using version 2.0 you can also try opening the new Model Browser
window. Once you have located a point close to the bony landmark you
need, take note of its sRel property. This is the point’s position in
the bone’s local coordinate system. You can then define your own
AnyRefNode with roughly the same sRel. If you insert an
AnyDrawRefFrame into the node’s definition, then you can easily see
where it is located when you load the model and modify its location
iteratively until you get it right.

The building block tutorial, lesson 3
http://www.anybodytech.com/89.0.html, demonstrates how to define a
new AnyRefNode on an existing foot from the repository.

A couple of things to notice:

  1. You do not need to work in the BRep part of the respository. You
    can add the nodes you need in the ARep part as demonstrated in the
    building block tutorial.

  2. In spite of this, you may want to go into the BRep part and copy
    one of the node definitions from there. The reason is that these
    definitions have scaling formulas built into them, and you probably
    want your node marker position to scale too.

Sorry about the wordy explanation. Please feel free to ask questions
on specific issues once you get started on the job.

Best regards,
AnyBody Support

— In anyscript@yahoogroups.com, “duttatil” <tilak.dutta@u…> wrote:
> Hi,
>
> I have a question about marker locations. We are using the
> standard “plug-in gait” marker set. Is there any documentation on
how
> we can refer to the marker locations if using the full body model?
>
> (I see in the gait3d application, they have given most of the
marker
> locations, but I don’t have any numbers for the upper body points.)
>
> Thanks,
> Tilak