Using a C3D file to drive a simulation

Hi everyone,

My name’s Dan, I’m new to the group. I’m a graduate student at Ball
State looking to take the leap into modeling and AnyBody looks to be
an intuitive interface for someone like myself with a little training
in C++/Java. So far I’m using the demo, and the tutorial has been
VERY well written and useful.

I do have some concern about how well the software will suit the
potential desired use of the model, though, which is to drive a
cycling model using information gathered from the ViCon Nexus
platform. I used the search function and only found one message on
the topic of forward dynamics. I know the program right now works in
an inverse dynamic fashion, but does anyone know if it will soon be
possible to feed in kinetics to drive the model? If not, which
modeling environment would be the best alternative for that sort of
purpose?

Thanks for any help,

Dan Leib

Hi Daniel

Welcome to the group.

Jep, if you have a background in c++/Java everything should be good:D

If you would like to drive a bicycling model from motion capture data,
you can just do so. The data you got from the ViCon Nexus platform is
kinematic motion capture data, right?
In principle you can take the bicycle model from the repository and
drive it with the kinematic data. I am not sure if I understand what
you need the forward dynamics for? Could you explain some more about
what you want to do?

Best regards

Christian, AnyBody Support

— In anyscript@yahoogroups.com, “daniel.leib” <daniel.leib@…> wrote:
>
> Hi everyone,
>
> My name’s Dan, I’m new to the group. I’m a graduate student at Ball
> State looking to take the leap into modeling and AnyBody looks to be
> an intuitive interface for someone like myself with a little training
> in C++/Java. So far I’m using the demo, and the tutorial has been
> VERY well written and useful.
>
> I do have some concern about how well the software will suit the
> potential desired use of the model, though, which is to drive a
> cycling model using information gathered from the ViCon Nexus
> platform. I used the search function and only found one message on
> the topic of forward dynamics. I know the program right now works in
> an inverse dynamic fashion, but does anyone know if it will soon be
> possible to feed in kinetics to drive the model? If not, which
> modeling environment would be the best alternative for that sort of
> purpose?
>
> Thanks for any help,
>
> Dan Leib
>

Hi Christian,

There are two main things we’re looking at using modeling for right now;
performance enhancement and predicting gait parameters.

Cycling is what we’re going to focus on first in regards to performance
because we figure it should be one of the easiest to learn since the bike
provides a number of constraints. What we’d like to be able to do is take
motion capture data and/or EMG data and use it to drive the model to accurately
predict what the effects on power output and other such parameters would be if
we changed the seat height, lengthened the crank slightly, changed the position
of the cleats on the shoe, etc.

The same type of idea is what we’d eventually be able to do with gait. A good
example would be predicting the effects of surgically moving a tendon (such as
rectus fem to the lateral knee for a CP patient with stiff-legged gait) on gait
parameters, ultimately leading to helping the patient walk fairly normally.

Would the software be able to handle these tasks assuming the programmer is up
to the challenge?

Thanks,

Dan

AnyBody Support <support@anybodytech.com> wrote:

Hi Daniel

Welcome to the group.

Jep, if you have a background in c++/Java everything should be good:D

If you would like to drive a bicycling model from motion capture data,
you can just do so. The data you got from the ViCon Nexus platform is
kinematic motion capture data, right?
In principle you can take the bicycle model from the repository and
drive it with the kinematic data. I am not sure if I understand what
you need the forward dynamics for? Could you explain some more about
what you want to do?

Best regards

Christian, AnyBody Support

— In anyscript@yahoogroups.com, “daniel.leib” <daniel.leib@…> wrote:
>
> Hi everyone,
>
> My name’s Dan, I’m new to the group. I’m a graduate student at Ball
> State looking to take the leap into modeling and AnyBody looks to be
> an intuitive interface for someone like myself with a little training
> in C++/Java. So far I’m using the demo, and the tutorial has been
> VERY well written and useful.
>
> I do have some concern about how well the software will suit the
> potential desired use of the model, though, which is to drive a
> cycling model using information gathered from the ViCon Nexus
> platform. I used the search function and only found one message on
> the topic of forward dynamics. I know the program right now works in
> an inverse dynamic fashion, but does anyone know if it will soon be
> possible to feed in kinetics to drive the model? If not, which
> modeling environment would be the best alternative for that sort of
> purpose?
>
> Thanks for any help,
>
> Dan Leib
>


Get your email and more, right on the new Yahoo.com

[Non-text portions of this message have been removed]

Hi Daniel

Ok. I see.
You want to enhance some parameters on the bike. Instead of optimizing
with respect to the output as you want, AnyBody gives you the
possibility to optimize with respect to the muscle activity. You can
set up the bicycle model, drive it with motion capture and but a
resistance on the crank. Then you can change the parameters you want,
like seat height, pedal arm length etc. and see if the muscle activity
is decreasing or increasing.

You could take a look at these two papers:
http://anybody.aau.dk/pdf/RioFullPaper.pdf which describes the
optimization of a bicycle by using springs to remove the so called
“dead center”.

When it comes to the modeling of the walk. You can easily take a
model, drive it with some kind of motion capture and force plate data
and then try to move a muscle and see how that effects the surrounding
muscles during the gait.

Anybody is a inverse dynamic tool, but you can synthesize movements
with it, and there will be held a webcast with the title: “How to
synthesize posture and movement with inverse dynamics” The 25th of
September.
It is not possible to drive the model with EMG.

Hope I answer you questions, else feel free to write again:D

Best regards
Christian, Anybody Support

— In anyscript@yahoogroups.com, Daniel Leib <daniel.leib@…> wrote:
>
> Hi Christian,
>
> There are two main things we’re looking at using modeling for
right now; performance enhancement and predicting gait parameters.
>
> Cycling is what we’re going to focus on first in regards to
performance because we figure it should be one of the easiest to learn
since the bike provides a number of constraints. What we’d like to be
able to do is take motion capture data and/or EMG data and use it to
drive the model to accurately predict what the effects on power output
and other such parameters would be if we changed the seat height,
lengthened the crank slightly, changed the position of the cleats on
the shoe, etc.
>
> The same type of idea is what we’d eventually be able to do with
gait. A good example would be predicting the effects of surgically
moving a tendon (such as rectus fem to the lateral knee for a CP
patient with stiff-legged gait) on gait parameters, ultimately leading
to helping the patient walk fairly normally.
>
> Would the software be able to handle these tasks assuming the
programmer is up to the challenge?
>
> Thanks,
>
> Dan
>
> AnyBody Support <support@…> wrote:
>
> Hi Daniel
>
> Welcome to the group.
>
> Jep, if you have a background in c++/Java everything should be good:D
>
> If you would like to drive a bicycling model from motion capture data,
> you can just do so. The data you got from the ViCon Nexus platform is
> kinematic motion capture data, right?
> In principle you can take the bicycle model from the repository and
> drive it with the kinematic data. I am not sure if I understand what
> you need the forward dynamics for? Could you explain some more about
> what you want to do?
>
> Best regards
>
> Christian, AnyBody Support
>
> — In anyscript@yahoogroups.com, “daniel.leib” <daniel.leib@> wrote:
> >
> > Hi everyone,
> >
> > My name’s Dan, I’m new to the group. I’m a graduate student at Ball
> > State looking to take the leap into modeling and AnyBody looks to be
> > an intuitive interface for someone like myself with a little training
> > in C++/Java. So far I’m using the demo, and the tutorial has been
> > VERY well written and useful.
> >
> > I do have some concern about how well the software will suit the
> > potential desired use of the model, though, which is to drive a
> > cycling model using information gathered from the ViCon Nexus
> > platform. I used the search function and only found one message on
> > the topic of forward dynamics. I know the program right now works in
> > an inverse dynamic fashion, but does anyone know if it will soon be
> > possible to feed in kinetics to drive the model? If not, which
> > modeling environment would be the best alternative for that sort of
> > purpose?
> >
> > Thanks for any help,
> >
> > Dan Leib
> >
>
>
>
>
>
>
> ---------------------------------
> Get your email and more, right on the new Yahoo.com
>
> [Non-text portions of this message have been removed]
>

Hi Christian,

Thanks for the quick reply - I’ll take a look at the cycling specific papers
as soon as I get a chance.

I’m pretty sure I understand what you’re saying about altering the bike and
seeing how that effects change in the rider, but I’ll wait for the webcast on
Monday before I ask any more questions on that as they may be answered.

I have spent the last couple days trying to import motion capture data from a
ViCon MX system to use to drive the Gait3D model and have run into a couple
problems. The first is general syntax problem that I just can’t figure out;
attached is a screenshot of the workstation with the error reported and the code
near where it was reported.

The second is regarding the compatability of the ascii .txt created by the
ViCon system and the way the markers are referenced within the model. If I
understand it correctly, the marker placement in the model is based on a local
reference frame where the the markers are placed {x,y,z} from the segment’s
center of mass? The ViCon Workstation output is in regards to the global
reference position, however, and this makes it extremely difficult to assign the
markers to the correct position on the model unless I’m missing something. I
looked at the Px.txt files, and the numbers seem to be generated in the same
format as the model wants to use them; how did you accomplish this? Does your
motion capture system output the ascii file in that format by default, or did
you have to do something in particular to the data?

Thanks for any help you can offer,

Dan

AnyBody Support <support@anybodytech.com> wrote:
Hi Daniel

Ok. I see.
You want to enhance some parameters on the bike. Instead of optimizing
with respect to the output as you want, AnyBody gives you the
possibility to optimize with respect to the muscle activity. You can
set up the bicycle model, drive it with motion capture and but a
resistance on the crank. Then you can change the parameters you want,
like seat height, pedal arm length etc. and see if the muscle activity
is decreasing or increasing.

You could take a look at these two papers:
http://anybody.aau.dk/pdf/RioFullPaper.pdf which describes the
optimization of a bicycle by using springs to remove the so called
“dead center”.

When it comes to the modeling of the walk. You can easily take a
model, drive it with some kind of motion capture and force plate data
and then try to move a muscle and see how that effects the surrounding
muscles during the gait.

Anybody is a inverse dynamic tool, but you can synthesize movements
with it, and there will be held a webcast with the title: “How to
synthesize posture and movement with inverse dynamics” The 25th of
September.
It is not possible to drive the model with EMG.

Hope I answer you questions, else feel free to write again:D

Best regards
Christian, Anybody Support

— In anyscript@yahoogroups.com, Daniel Leib <daniel.leib@…> wrote:
>
> Hi Christian,
>
> There are two main things we’re looking at using modeling for
right now; performance enhancement and predicting gait parameters.
>
> Cycling is what we’re going to focus on first in regards to
performance because we figure it should be one of the easiest to learn
since the bike provides a number of constraints. What we’d like to be
able to do is take motion capture data and/or EMG data and use it to
drive the model to accurately predict what the effects on power output
and other such parameters would be if we changed the seat height,
lengthened the crank slightly, changed the position of the cleats on
the shoe, etc.
>
> The same type of idea is what we’d eventually be able to do with
gait. A good example would be predicting the effects of surgically
moving a tendon (such as rectus fem to the lateral knee for a CP
patient with stiff-legged gait) on gait parameters, ultimately leading
to helping the patient walk fairly normally.
>
> Would the software be able to handle these tasks assuming the
programmer is up to the challenge?
>
> Thanks,
>
> Dan
>
> AnyBody Support <support@…> wrote:
>
> Hi Daniel
>
> Welcome to the group.
>
> Jep, if you have a background in c++/Java everything should be good:D
>
> If you would like to drive a bicycling model from motion capture data,
> you can just do so. The data you got from the ViCon Nexus platform is
> kinematic motion capture data, right?
> In principle you can take the bicycle model from the repository and
> drive it with the kinematic data. I am not sure if I understand what
> you need the forward dynamics for? Could you explain some more about
> what you want to do?
>
> Best regards
>
> Christian, AnyBody Support
>
> — In anyscript@yahoogroups.com, “daniel.leib” <daniel.leib@> wrote:
> >
> > Hi everyone,
> >
> > My name’s Dan, I’m new to the group. I’m a graduate student at Ball
> > State looking to take the leap into modeling and AnyBody looks to be
> > an intuitive interface for someone like myself with a little training
> > in C++/Java. So far I’m using the demo, and the tutorial has been
> > VERY well written and useful.
> >
> > I do have some concern about how well the software will suit the
> > potential desired use of the model, though, which is to drive a
> > cycling model using information gathered from the ViCon Nexus
> > platform. I used the search function and only found one message on
> > the topic of forward dynamics. I know the program right now works in
> > an inverse dynamic fashion, but does anyone know if it will soon be
> > possible to feed in kinetics to drive the model? If not, which
> > modeling environment would be the best alternative for that sort of
> > purpose?
> >
> > Thanks for any help,
> >
> > Dan Leib
> >
>
>
>
>
>
>
> ---------------------------------
> Get your email and more, right on the new Yahoo.com
>
> [Non-text portions of this message have been removed]
>


Stay in the know. Pulse on the new Yahoo.com. Check it out.

[Non-text portions of this message have been removed]

Hi Daniel

You are welcome:D

I can’t see anything attached? You can just put it in the mail or post
it as a file?

Regarding to the coordinate systems, the marker position can be made
in global coordinates.
You can use a AnyKinLinear to measure the translation between the
global refrence frame and your local. And a AnyKinRotational to
measure the rotation.
You can zip the model and upload it to the file share and then we can
have a look:D
But please send the error message you are getting.

Best regards

Christian, AnyBody Support

— In anyscript@yahoogroups.com, Daniel Leib <daniel.leib@…> wrote:
>
> Hi Christian,
>
> Thanks for the quick reply - I’ll take a look at the cycling
specific papers as soon as I get a chance.
>
> I’m pretty sure I understand what you’re saying about altering the
bike and seeing how that effects change in the rider, but I’ll wait
for the webcast on Monday before I ask any more questions on that as
they may be answered.
>
> I have spent the last couple days trying to import motion capture
data from a ViCon MX system to use to drive the Gait3D model and have
run into a couple problems. The first is general syntax problem that
I just can’t figure out; attached is a screenshot of the workstation
with the error reported and the code near where it was reported.
>
> The second is regarding the compatability of the ascii .txt
created by the ViCon system and the way the markers are referenced
within the model. If I understand it correctly, the marker placement
in the model is based on a local reference frame where the the markers
are placed {x,y,z} from the segment’s center of mass? The ViCon
Workstation output is in regards to the global reference position,
however, and this makes it extremely difficult to assign the markers
to the correct position on the model unless I’m missing something. I
looked at the Px.txt files, and the numbers seem to be generated in
the same format as the model wants to use them; how did you accomplish
this? Does your motion capture system output the ascii file in that
format by default, or did you have to do something in particular to
the data?
>
> Thanks for any help you can offer,
>
> Dan
>
> AnyBody Support <support@…> wrote:
> Hi Daniel
>
> Ok. I see.
> You want to enhance some parameters on the bike. Instead of optimizing
> with respect to the output as you want, AnyBody gives you the
> possibility to optimize with respect to the muscle activity. You can
> set up the bicycle model, drive it with motion capture and but a
> resistance on the crank. Then you can change the parameters you want,
> like seat height, pedal arm length etc. and see if the muscle activity
> is decreasing or increasing.
>
> You could take a look at these two papers:
> http://anybody.aau.dk/pdf/RioFullPaper.pdf which describes the
> optimization of a bicycle by using springs to remove the so called
> “dead center”.
>
> When it comes to the modeling of the walk. You can easily take a
> model, drive it with some kind of motion capture and force plate data
> and then try to move a muscle and see how that effects the surrounding
> muscles during the gait.
>
> Anybody is a inverse dynamic tool, but you can synthesize movements
> with it, and there will be held a webcast with the title: “How to
> synthesize posture and movement with inverse dynamics” The 25th of
> September.
> It is not possible to drive the model with EMG.
>
> Hope I answer you questions, else feel free to write again:D
>
> Best regards
> Christian, Anybody Support
>
> — In anyscript@yahoogroups.com, Daniel Leib <daniel.leib@> wrote:
> >
> > Hi Christian,
> >
> > There are two main things we’re looking at using modeling for
> right now; performance enhancement and predicting gait parameters.
> >
> > Cycling is what we’re going to focus on first in regards to
> performance because we figure it should be one of the easiest to learn
> since the bike provides a number of constraints. What we’d like to be
> able to do is take motion capture data and/or EMG data and use it to
> drive the model to accurately predict what the effects on power output
> and other such parameters would be if we changed the seat height,
> lengthened the crank slightly, changed the position of the cleats on
> the shoe, etc.
> >
> > The same type of idea is what we’d eventually be able to do with
> gait. A good example would be predicting the effects of surgically
> moving a tendon (such as rectus fem to the lateral knee for a CP
> patient with stiff-legged gait) on gait parameters, ultimately leading
> to helping the patient walk fairly normally.
> >
> > Would the software be able to handle these tasks assuming the
> programmer is up to the challenge?
> >
> > Thanks,
> >
> > Dan
> >
> > AnyBody Support <support@> wrote:
> >
> > Hi Daniel
> >
> > Welcome to the group.
> >
> > Jep, if you have a background in c++/Java everything should be good:D
> >
> > If you would like to drive a bicycling model from motion capture data,
> > you can just do so. The data you got from the ViCon Nexus platform is
> > kinematic motion capture data, right?
> > In principle you can take the bicycle model from the repository and
> > drive it with the kinematic data. I am not sure if I understand what
> > you need the forward dynamics for? Could you explain some more about
> > what you want to do?
> >
> > Best regards
> >
> > Christian, AnyBody Support
> >
> > — In anyscript@yahoogroups.com, “daniel.leib” <daniel.leib@> wrote:
> > >
> > > Hi everyone,
> > >
> > > My name’s Dan, I’m new to the group. I’m a graduate student at Ball
> > > State looking to take the leap into modeling and AnyBody looks
to be
> > > an intuitive interface for someone like myself with a little
training
> > > in C++/Java. So far I’m using the demo, and the tutorial has been
> > > VERY well written and useful.
> > >
> > > I do have some concern about how well the software will suit the
> > > potential desired use of the model, though, which is to drive a
> > > cycling model using information gathered from the ViCon Nexus
> > > platform. I used the search function and only found one message on
> > > the topic of forward dynamics. I know the program right now
works in
> > > an inverse dynamic fashion, but does anyone know if it will soon be
> > > possible to feed in kinetics to drive the model? If not, which
> > > modeling environment would be the best alternative for that sort of
> > > purpose?
> > >
> > > Thanks for any help,
> > >
> > > Dan Leib
> > >
> >
> >
> >
> >
> >
> >
> > ---------------------------------
> > Get your email and more, right on the new Yahoo.com
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
>
> ---------------------------------
> Stay in the know. Pulse on the new Yahoo.com. Check it out.
>
> [Non-text portions of this message have been removed]
>

Hi Christian,

I have no idea why the Word file didn’t show up (probably a BSU firewall
issue, that thing’s been driving me nuts), but I posted the zipped file to the
yahoo group file depository. The name is PlugInGait.zip . Thanks for taking a
look at it, I tried to figure out the problem over the weekend and got nowhere.

A couple notes on it:

The error message I keep getting is …twolegs\calibrationsequence.any
‘AnyFolder’ not expected (5)

I had to comment out the sacrum point and marker as our standard marker set
doesn’t use it; the points we use are (right and left): Asis, Psis, Thigh
(middle of thigh), lateral knee, mid shank, and the three heel/foot markers are
the same. It makes for 16 markers, which I’m pretty sure I have defined
correctly on the model though I could be a little off. I was worried that the
removal of the sacrum might pose a problem, but after looking through all the
folders I couldn’t see anything that should return this particular error.

I’m also not sure how to define the marker points globally as you mentioned,
but I’ll look through the tutorials on those commands, I haven’t gotten that far
in the learning process yet :slight_smile: How did your lab get the motion capture output
in the format you did, though? It looks like it’d be a lot easier to customize
the model per individual using that technique.

Thanks for your help, I know I have a lot of questions :slight_smile:

-Dan

AnyBody Support <support@anybodytech.com> wrote:
Hi Daniel

You are welcome:D

I can’t see anything attached? You can just put it in the mail or post
it as a file?

Regarding to the coordinate systems, the marker position can be made
in global coordinates.
You can use a AnyKinLinear to measure the translation between the
global refrence frame and your local. And a AnyKinRotational to
measure the rotation.
You can zip the model and upload it to the file share and then we can
have a look:D
But please send the error message you are getting.

Best regards

Christian, AnyBody Support

— In anyscript@yahoogroups.com, Daniel Leib <daniel.leib@…> wrote:
>
> Hi Christian,
>
> Thanks for the quick reply - I’ll take a look at the cycling
specific papers as soon as I get a chance.
>
> I’m pretty sure I understand what you’re saying about altering the
bike and seeing how that effects change in the rider, but I’ll wait
for the webcast on Monday before I ask any more questions on that as
they may be answered.
>
> I have spent the last couple days trying to import motion capture
data from a ViCon MX system to use to drive the Gait3D model and have
run into a couple problems. The first is general syntax problem that
I just can’t figure out; attached is a screenshot of the workstation
with the error reported and the code near where it was reported.
>
> The second is regarding the compatability of the ascii .txt
created by the ViCon system and the way the markers are referenced
within the model. If I understand it correctly, the marker placement
in the model is based on a local reference frame where the the markers
are placed {x,y,z} from the segment’s center of mass? The ViCon
Workstation output is in regards to the global reference position,
however, and this makes it extremely difficult to assign the markers
to the correct position on the model unless I’m missing something. I
looked at the Px.txt files, and the numbers seem to be generated in
the same format as the model wants to use them; how did you accomplish
this? Does your motion capture system output the ascii file in that
format by default, or did you have to do something in particular to
the data?
>
> Thanks for any help you can offer,
>
> Dan
>
> AnyBody Support <support@…> wrote:
> Hi Daniel
>
> Ok. I see.
> You want to enhance some parameters on the bike. Instead of optimizing
> with respect to the output as you want, AnyBody gives you the
> possibility to optimize with respect to the muscle activity. You can
> set up the bicycle model, drive it with motion capture and but a
> resistance on the crank. Then you can change the parameters you want,
> like seat height, pedal arm length etc. and see if the muscle activity
> is decreasing or increasing.
>
> You could take a look at these two papers:
> http://anybody.aau.dk/pdf/RioFullPaper.pdf which describes the
> optimization of a bicycle by using springs to remove the so called
> “dead center”.
>
> When it comes to the modeling of the walk. You can easily take a
> model, drive it with some kind of motion capture and force plate data
> and then try to move a muscle and see how that effects the surrounding
> muscles during the gait.
>
> Anybody is a inverse dynamic tool, but you can synthesize movements
> with it, and there will be held a webcast with the title: “How to
> synthesize posture and movement with inverse dynamics” The 25th of
> September.
> It is not possible to drive the model with EMG.
>
> Hope I answer you questions, else feel free to write again:D
>
> Best regards
> Christian, Anybody Support
>
> — In anyscript@yahoogroups.com, Daniel Leib <daniel.leib@> wrote:
> >
> > Hi Christian,
> >
> > There are two main things we’re looking at using modeling for
> right now; performance enhancement and predicting gait parameters.
> >
> > Cycling is what we’re going to focus on first in regards to
> performance because we figure it should be one of the easiest to learn
> since the bike provides a number of constraints. What we’d like to be
> able to do is take motion capture data and/or EMG data and use it to
> drive the model to accurately predict what the effects on power output
> and other such parameters would be if we changed the seat height,
> lengthened the crank slightly, changed the position of the cleats on
> the shoe, etc.
> >
> > The same type of idea is what we’d eventually be able to do with
> gait. A good example would be predicting the effects of surgically
> moving a tendon (such as rectus fem to the lateral knee for a CP
> patient with stiff-legged gait) on gait parameters, ultimately leading
> to helping the patient walk fairly normally.
> >
> > Would the software be able to handle these tasks assuming the
> programmer is up to the challenge?
> >
> > Thanks,
> >
> > Dan
> >
> > AnyBody Support <support@> wrote:
> >
> > Hi Daniel
> >
> > Welcome to the group.
> >
> > Jep, if you have a background in c++/Java everything should be good:D
> >
> > If you would like to drive a bicycling model from motion capture data,
> > you can just do so. The data you got from the ViCon Nexus platform is
> > kinematic motion capture data, right?
> > In principle you can take the bicycle model from the repository and
> > drive it with the kinematic data. I am not sure if I understand what
> > you need the forward dynamics for? Could you explain some more about
> > what you want to do?
> >
> > Best regards
> >
> > Christian, AnyBody Support
> >
> > — In anyscript@yahoogroups.com, “daniel.leib” <daniel.leib@> wrote:
> > >
> > > Hi everyone,
> > >
> > > My name’s Dan, I’m new to the group. I’m a graduate student at Ball
> > > State looking to take the leap into modeling and AnyBody looks
to be
> > > an intuitive interface for someone like myself with a little
training
> > > in C++/Java. So far I’m using the demo, and the tutorial has been
> > > VERY well written and useful.
> > >
> > > I do have some concern about how well the software will suit the
> > > potential desired use of the model, though, which is to drive a
> > > cycling model using information gathered from the ViCon Nexus
> > > platform. I used the search function and only found one message on
> > > the topic of forward dynamics. I know the program right now
works in
> > > an inverse dynamic fashion, but does anyone know if it will soon be
> > > possible to feed in kinetics to drive the model? If not, which
> > > modeling environment would be the best alternative for that sort of
> > > purpose?
> > >
> > > Thanks for any help,
> > >
> > > Dan Leib
> > >
> >
> >
> >
> >
> >
> >
> > ---------------------------------
> > Get your email and more, right on the new Yahoo.com
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
>
> ---------------------------------
> Stay in the know. Pulse on the new Yahoo.com. Check it out.
>
> [Non-text portions of this message have been removed]
>


Get your email and more, right on the new Yahoo.com

[Non-text portions of this message have been removed]

Hi

I have read your discourse with Daniel with interest as I too will
require to drive an AnyBody model with C3D data (Vicon flavour) but I
am not as advanced as Daniel. You state that this task can be
completed but could you inform me how (or at least point me in the
direction of the appropriate commands).

Thanks

James

— In anyscript@yahoogroups.com, Daniel Leib <daniel.leib@…> wrote:
>
> Hi Christian,
>
> I have no idea why the Word file didn’t show up (probably a BSU
firewall issue, that thing’s been driving me nuts), but I posted the
zipped file to the yahoo group file depository. The name is
PlugInGait.zip . Thanks for taking a look at it, I tried to figure
out the problem over the weekend and got nowhere.
>
> A couple notes on it:
>
> The error message I keep getting
is …twolegs\calibrationsequence.any ‘AnyFolder’ not expected (5)
>
> I had to comment out the sacrum point and marker as our standard
marker set doesn’t use it; the points we use are (right and left):
Asis, Psis, Thigh (middle of thigh), lateral knee, mid shank, and the
three heel/foot markers are the same. It makes for 16 markers, which
I’m pretty sure I have defined correctly on the model though I could
be a little off. I was worried that the removal of the sacrum might
pose a problem, but after looking through all the folders I couldn’t
see anything that should return this particular error.
>
> I’m also not sure how to define the marker points globally as you
mentioned, but I’ll look through the tutorials on those commands, I
haven’t gotten that far in the learning process yet :slight_smile: How did your
lab get the motion capture output in the format you did, though? It
looks like it’d be a lot easier to customize the model per individual
using that technique.
>
> Thanks for your help, I know I have a lot of questions :slight_smile:
>
> -Dan
>
> AnyBody Support <support@…> wrote:
> Hi Daniel
>
> You are welcome:D
>
> I can’t see anything attached? You can just put it in the mail or
post
> it as a file?
>
> Regarding to the coordinate systems, the marker position can be made
> in global coordinates.
> You can use a AnyKinLinear to measure the translation between the
> global refrence frame and your local. And a AnyKinRotational to
> measure the rotation.
> You can zip the model and upload it to the file share and then we
can
> have a look:D
> But please send the error message you are getting.
>
> Best regards
>
> Christian, AnyBody Support
>
> — In anyscript@yahoogroups.com, Daniel Leib <daniel.leib@> wrote:
> >
> > Hi Christian,
> >
> > Thanks for the quick reply - I’ll take a look at the cycling
> specific papers as soon as I get a chance.
> >
> > I’m pretty sure I understand what you’re saying about altering the
> bike and seeing how that effects change in the rider, but I’ll wait
> for the webcast on Monday before I ask any more questions on that as
> they may be answered.
> >
> > I have spent the last couple days trying to import motion capture
> data from a ViCon MX system to use to drive the Gait3D model and
have
> run into a couple problems. The first is general syntax problem that
> I just can’t figure out; attached is a screenshot of the workstation
> with the error reported and the code near where it was reported.
> >
> > The second is regarding the compatability of the ascii .txt
> created by the ViCon system and the way the markers are referenced
> within the model. If I understand it correctly, the marker placement
> in the model is based on a local reference frame where the the
markers
> are placed {x,y,z} from the segment’s center of mass? The ViCon
> Workstation output is in regards to the global reference position,
> however, and this makes it extremely difficult to assign the markers
> to the correct position on the model unless I’m missing something. I
> looked at the Px.txt files, and the numbers seem to be generated in
> the same format as the model wants to use them; how did you
accomplish
> this? Does your motion capture system output the ascii file in that
> format by default, or did you have to do something in particular to
> the data?
> >
> > Thanks for any help you can offer,
> >
> > Dan
> >
> > AnyBody Support <support@> wrote:
> > Hi Daniel
> >
> > Ok. I see.
> > You want to enhance some parameters on the bike. Instead of
optimizing
> > with respect to the output as you want, AnyBody gives you the
> > possibility to optimize with respect to the muscle activity. You
can
> > set up the bicycle model, drive it with motion capture and but a
> > resistance on the crank. Then you can change the parameters you
want,
> > like seat height, pedal arm length etc. and see if the muscle
activity
> > is decreasing or increasing.
> >
> > You could take a look at these two papers:
> > http://anybody.aau.dk/pdf/RioFullPaper.pdf which describes the
> > optimization of a bicycle by using springs to remove the so called
> > “dead center”.
> >
> > When it comes to the modeling of the walk. You can easily take a
> > model, drive it with some kind of motion capture and force plate
data
> > and then try to move a muscle and see how that effects the
surrounding
> > muscles during the gait.
> >
> > Anybody is a inverse dynamic tool, but you can synthesize
movements
> > with it, and there will be held a webcast with the title: “How to
> > synthesize posture and movement with inverse dynamics” The 25th of
> > September.
> > It is not possible to drive the model with EMG.
> >
> > Hope I answer you questions, else feel free to write again:D
> >
> > Best regards
> > Christian, Anybody Support
> >
> > — In anyscript@yahoogroups.com, Daniel Leib <daniel.leib@>
wrote:
> > >
> > > Hi Christian,
> > >
> > > There are two main things we’re looking at using modeling for
> > right now; performance enhancement and predicting gait
parameters.
> > >
> > > Cycling is what we’re going to focus on first in regards to
> > performance because we figure it should be one of the easiest to
learn
> > since the bike provides a number of constraints. What we’d like
to be
> > able to do is take motion capture data and/or EMG data and use it
to
> > drive the model to accurately predict what the effects on power
output
> > and other such parameters would be if we changed the seat height,
> > lengthened the crank slightly, changed the position of the cleats
on
> > the shoe, etc.
> > >
> > > The same type of idea is what we’d eventually be able to do with
> > gait. A good example would be predicting the effects of surgically
> > moving a tendon (such as rectus fem to the lateral knee for a CP
> > patient with stiff-legged gait) on gait parameters, ultimately
leading
> > to helping the patient walk fairly normally.
> > >
> > > Would the software be able to handle these tasks assuming the
> > programmer is up to the challenge?
> > >
> > > Thanks,
> > >
> > > Dan
> > >
> > > AnyBody Support <support@> wrote:
> > >
> > > Hi Daniel
> > >
> > > Welcome to the group.
> > >
> > > Jep, if you have a background in c++/Java everything should be
good:D
> > >
> > > If you would like to drive a bicycling model from motion
capture data,
> > > you can just do so. The data you got from the ViCon Nexus
platform is
> > > kinematic motion capture data, right?
> > > In principle you can take the bicycle model from the repository
and
> > > drive it with the kinematic data. I am not sure if I understand
what
> > > you need the forward dynamics for? Could you explain some more
about
> > > what you want to do?
> > >
> > > Best regards
> > >
> > > Christian, AnyBody Support
> > >
> > > — In anyscript@yahoogroups.com, “daniel.leib” <daniel.leib@>
wrote:
> > > >
> > > > Hi everyone,
> > > >
> > > > My name’s Dan, I’m new to the group. I’m a graduate student
at Ball
> > > > State looking to take the leap into modeling and AnyBody looks
> to be
> > > > an intuitive interface for someone like myself with a little
> training
> > > > in C++/Java. So far I’m using the demo, and the tutorial has
been
> > > > VERY well written and useful.
> > > >
> > > > I do have some concern about how well the software will suit
the
> > > > potential desired use of the model, though, which is to drive
a
> > > > cycling model using information gathered from the ViCon Nexus
> > > > platform. I used the search function and only found one
message on
> > > > the topic of forward dynamics. I know the program right now
> works in
> > > > an inverse dynamic fashion, but does anyone know if it will
soon be
> > > > possible to feed in kinetics to drive the model? If not,
which
> > > > modeling environment would be the best alternative for that
sort of
> > > > purpose?
> > > >
> > > > Thanks for any help,
> > > >
> > > > Dan Leib
> > > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > ---------------------------------
> > > Get your email and more, right on the new Yahoo.com
> > >
> > > [Non-text portions of this message have been removed]
> > >
> >
> >
> >
> >
> >
> >
> > ---------------------------------
> > Stay in the know. Pulse on the new Yahoo.com. Check it out.
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
>
> ---------------------------------
> Get your email and more, right on the new Yahoo.com
>
> [Non-text portions of this message have been removed]
>

Hi

If you received my previous posting about driving an AnyBody model from
C3D data…please ignore it! In the previous 5 minutes since I sent
it I think I have figured it out. Derive a kinematic measure from the
corresponding position on the model and drive it with the C3D data (?)
whilst being careful about the number of DOFs and constraints. Ah, how
is this tabulated data input??

Sorry about the confusion (but I suspect it will happen again!!).

Thanks

James

Hi Dan

I have taken a look on your model “PluginGaitWhileWorking.any” and resolved
two issues; I have uploaded the file PluginGaitV2.zip

1 In the file PluginGaitJointAndDrivers.any there was a misaligned bracket!
This can produce errors like “AnyFolder not expected” or similar. The error
was located where you had out commented the SacrumLy measureorganizer, you
needed to out comment a few lines more in order to have out commented the
entire driver.

When getting this kind of error you can always mark up the entire text in
the file and press Alt+F8 this will auto indent the text and it possible to
check if the brackets match.

I needed to out comment the AsisZDrv also, because the measure organizer it
used is now out commented, you need to replace this driver with another
driver which drivers the height of the pelvis.

2: In the file PlugInGaitMotionTrackerInclude.any I have removed the last
marker listed, there is not data in the file P16.txt which it is using.

These changes make the model load, but it will not be able to run before the
removed driver is replaced by an equivalent one :wink:

Best regards

Søren, AnyBody Support


From: anyscript@yahoogroups.com [mailto:anyscript@yahoogroups.com] On Behalf
Of Daniel Leib
Sent: 25. september 2006 16:06
To: anyscript@yahoogroups.com
Subject: Re: [anyscript] Re: Using a C3D file to drive a simulation

Hi Christian,

I have no idea why the Word file didn’t show up (probably a BSU firewall
issue, that thing’s been driving me nuts), but I posted the zipped file to
the yahoo group file depository. The name is PlugInGait.zip . Thanks for
taking a look at it, I tried to figure out the problem over the weekend and
got nowhere.

A couple notes on it:

The error message I keep getting is …twolegs\calibrationsequence.any
‘AnyFolder’ not expected (5)

I had to comment out the sacrum point and marker as our standard marker set
doesn’t use it; the points we use are (right and left): Asis, Psis, Thigh
(middle of thigh), lateral knee, mid shank, and the three heel/foot markers
are the same. It makes for 16 markers, which I’m pretty sure I have defined
correctly on the model though I could be a little off. I was worried that
the removal of the sacrum might pose a problem, but after looking through
all the folders I couldn’t see anything that should return this particular
error.

I’m also not sure how to define the marker points globally as you mentioned,
but I’ll look through the tutorials on those commands, I haven’t gotten that
far in the learning process yet :slight_smile: How did your lab get the motion capture
output in the format you did, though? It looks like it’d be a lot easier to
customize the model per individual using that technique.

Thanks for your help, I know I have a lot of questions :slight_smile:

-Dan

AnyBody Support <support@anybodytech <mailto:support%40anybodytech.com>
.com> wrote:
Hi Daniel

You are welcome:D

I can’t see anything attached? You can just put it in the mail or post
it as a file?

Regarding to the coordinate systems, the marker position can be made
in global coordinates.
You can use a AnyKinLinear to measure the translation between the
global refrence frame and your local. And a AnyKinRotational to
measure the rotation.
You can zip the model and upload it to the file share and then we can
have a look:D
But please send the error message you are getting.

Best regards

Christian, AnyBody Support

— In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com> ps.com,
Daniel Leib <daniel.leib@…> wrote:
>
> Hi Christian,
>
> Thanks for the quick reply - I’ll take a look at the cycling
specific papers as soon as I get a chance.
>
> I’m pretty sure I understand what you’re saying about altering the
bike and seeing how that effects change in the rider, but I’ll wait
for the webcast on Monday before I ask any more questions on that as
they may be answered.
>
> I have spent the last couple days trying to import motion capture
data from a ViCon MX system to use to drive the Gait3D model and have
run into a couple problems. The first is general syntax problem that
I just can’t figure out; attached is a screenshot of the workstation
with the error reported and the code near where it was reported.
>
> The second is regarding the compatability of the ascii .txt
created by the ViCon system and the way the markers are referenced
within the model. If I understand it correctly, the marker placement
in the model is based on a local reference frame where the the markers
are placed {x,y,z} from the segment’s center of mass? The ViCon
Workstation output is in regards to the global reference position,
however, and this makes it extremely difficult to assign the markers
to the correct position on the model unless I’m missing something. I
looked at the Px.txt files, and the numbers seem to be generated in
the same format as the model wants to use them; how did you accomplish
this? Does your motion capture system output the ascii file in that
format by default, or did you have to do something in particular to
the data?
>
> Thanks for any help you can offer,
>
> Dan
>
> AnyBody Support <support@…> wrote:
> Hi Daniel
>
> Ok. I see.
> You want to enhance some parameters on the bike. Instead of optimizing
> with respect to the output as you want, AnyBody gives you the
> possibility to optimize with respect to the muscle activity. You can
> set up the bicycle model, drive it with motion capture and but a
> resistance on the crank. Then you can change the parameters you want,
> like seat height, pedal arm length etc. and see if the muscle activity
> is decreasing or increasing.
>
> You could take a look at these two papers:
> http://anybody. <http://anybody.aau.dk/pdf/RioFullPaper.pdf>
aau.dk/pdf/RioFullPaper.pdf which describes the
> optimization of a bicycle by using springs to remove the so called
> “dead center”.
>
> When it comes to the modeling of the walk. You can easily take a
> model, drive it with some kind of motion capture and force plate data
> and then try to move a muscle and see how that effects the surrounding
> muscles during the gait.
>
> Anybody is a inverse dynamic tool, but you can synthesize movements
> with it, and there will be held a webcast with the title: “How to
> synthesize posture and movement with inverse dynamics” The 25th of
> September.
> It is not possible to drive the model with EMG.
>
> Hope I answer you questions, else feel free to write again:D
>
> Best regards
> Christian, Anybody Support
>
> — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com> ps.com,
Daniel Leib <daniel.leib@> wrote:
> >
> > Hi Christian,
> >
> > There are two main things we’re looking at using modeling for
> right now; performance enhancement and predicting gait parameters.
> >
> > Cycling is what we’re going to focus on first in regards to
> performance because we figure it should be one of the easiest to learn
> since the bike provides a number of constraints. What we’d like to be
> able to do is take motion capture data and/or EMG data and use it to
> drive the model to accurately predict what the effects on power output
> and other such parameters would be if we changed the seat height,
> lengthened the crank slightly, changed the position of the cleats on
> the shoe, etc.
> >
> > The same type of idea is what we’d eventually be able to do with
> gait. A good example would be predicting the effects of surgically
> moving a tendon (such as rectus fem to the lateral knee for a CP
> patient with stiff-legged gait) on gait parameters, ultimately leading
> to helping the patient walk fairly normally.
> >
> > Would the software be able to handle these tasks assuming the
> programmer is up to the challenge?
> >
> > Thanks,
> >
> > Dan
> >
> > AnyBody Support <support@> wrote:
> >
> > Hi Daniel
> >
> > Welcome to the group.
> >
> > Jep, if you have a background in c++/Java everything should be good:D
> >
> > If you would like to drive a bicycling model from motion capture data,
> > you can just do so. The data you got from the ViCon Nexus platform is
> > kinematic motion capture data, right?
> > In principle you can take the bicycle model from the repository and
> > drive it with the kinematic data. I am not sure if I understand what
> > you need the forward dynamics for? Could you explain some more about
> > what you want to do?
> >
> > Best regards
> >
> > Christian, AnyBody Support
> >
> > — In anyscript@yahoogrou <mailto:anyscript%40yahoogroups.com> ps.com,
“daniel.leib” <daniel.leib@> wrote:
> > >
> > > Hi everyone,
> > >
> > > My name’s Dan, I’m new to the group. I’m a graduate student at Ball
> > > State looking to take the leap into modeling and AnyBody looks
to be
> > > an intuitive interface for someone like myself with a little
training
> > > in C++/Java. So far I’m using the demo, and the tutorial has been
> > > VERY well written and useful.
> > >
> > > I do have some concern about how well the software will suit the
> > > potential desired use of the model, though, which is to drive a
> > > cycling model using information gathered from the ViCon Nexus
> > > platform. I used the search function and only found one message on
> > > the topic of forward dynamics. I know the program right now
works in
> > > an inverse dynamic fashion, but does anyone know if it will soon be
> > > possible to feed in kinetics to drive the model? If not, which
> > > modeling environment would be the best alternative for that sort of
> > > purpose?
> > >
> > > Thanks for any help,
> > >
> > > Dan Leib
> > >
> >
> >
> >
> >
> >
> >
> > ---------------------------------
> > Get your email and more, right on the new Yahoo.com
> >
> > [Non-text portions of this message have been removed]
> >
>
>
>
>
>
>
> ---------------------------------
> Stay in the know. Pulse on the new Yahoo.com. Check it out.
>
> [Non-text portions of this message have been removed]
>


Get your email and more, right on the new Yahoo.com

[Non-text portions of this message have been removed]

[Non-text portions of this message have been removed]

Hi James

Yes. Thats ok

Best regards
Christian, AnyBody Support

— In anyscript@yahoogroups.com, “jamesshippen” <jamesshippen@…> wrote:
>
> Hi
>
> If you received my previous posting about driving an AnyBody model from
> C3D data…please ignore it! In the previous 5 minutes since I sent
> it I think I have figured it out. Derive a kinematic measure from the
> corresponding position on the model and drive it with the C3D data (?)
> whilst being careful about the number of DOFs and constraints. Ah, how
> is this tabulated data input??
>
> Sorry about the confusion (but I suspect it will happen again!!).
>
> Thanks
>
> James
>