initial positions

Hi,

to define a certain posture for a model, we have two ways whether to use the mannequin file or to define the position and orientation for each segment in a specific coordinate system …

my questions are :

– this is an important question so please provide me with the details as much as possible… What are the landmarks on the body which I should know to define a certain posture?how can I know the accurate orientation for them?

– when I define (r0) for a segment, where does this point lay on the segment?is it the center point of the segment?

– also can you please explain and clarify the way to deal with the drivers, because I don’t understand how to define them (pos, vel) …

thank you for your help…

Kind Regards,
Zayd

Hi,
basically there are a few possiblities to drive a model. In all cases we need Drivers to provide the motion. The Mannequin file is used if you want to provide simple joint angles. You specifiy the position of a joint and its velocity during the motion. You can create other Drivers by using Kinematic measures. Furthermore you can use external data from motion capture experiments to drive a model. Please have a look at the tutorials http://www.anybodytech.com/fileadmin/AnyBody/Docs/Tutorials/Making_things_move/lesson1.html and the tips and tricks section in the wiki.

If you want to get the accurate motion of parts of the body you should use a motion capture system and a good marker set, see e.g the GaitFullBody example. Its not a easy task to say which bony landmarks are the right ones. It depends on your application. We also have no standard description here, just because it is usually not needed.
Dirvers basically state how a certain kinematic measure (linear or rotational) changes over time. Please have a look at the FreePosture example and the Drivers there.
Best regards,
Sebastian