How to read C3D file

Main Forum
1

Hi AnyBody support,

I always appreciate your help.
By the way, I tried to read another C3D file as I have to change sampling frequency 250Hz to 125Hz.
I have already made new C3D file which is 125Hz by using Venus3D which can modify both C3D and CSV file.
I have already tried to read the file(250Hz) and it’s succeed, but new one(125Hz), it’s not.
Please find any solution for this problem.
I attached whole files to run this program (GaitFullBody_TUT_With_Force.zip).
And succeeded C3D file is “kobayashi_0030802-processed.c3d”.
Failed C3D file is “kobayashi_0030802-processed_fail.c3d”.
AMS is ver 5.1 and AMMR is ver 1.4.

I beg your kindness,

Akira

2

Dear Akira,

I looked at the C3D files and I found something wrong. It might be a simple fix, but I’m not sure.

In the C3D file that fails the marker names are “point 1”, while in the running model they are “point1”. AnyBody will have trouble processing this empty space, can you try and change the marker names (just delete the space) and see if it will run?

3

Thank you for your message,

I wasn’t synchronized Mocap and force plate data.
I modified C3D of Mocap data.
I read Mocap and force plate data again,
But marker has traveled farther and farther away from model.
How can I move together marker and model?

I attached whole files to run this program (GaitFullBody_TUT_With_Force.zip).
AMS is ver 5.1 and AMMR is ver 1.4.

I beg your kindness,

Akira

4

Hi Akira,

First, you should always check that you could run the ‘MotionAndParameterOptimizationModel’ process with your new C3D files.
You can not use the same kinematics file if you use different C3D files.

And I tried to modify your TrialSpecificData.any file.

  AnyIntVar FirstFrameOffset = 0;
  AnyIntVar LastFrameOffset = 20;
  AnyIntVar NewFirstFrame = Main.ModelSetup.FirstFrame+FirstFrameOffset;
  AnyIntVar NewLastFrame = Main.ModelSetup.LastFrame - LastFrameOffset;
  
  AnyFloatVar  tStart = NewFirstFrame / Main.ModelSetup.C3DFileData.Header.VideoFrameRate;
  AnyFloatVar  tEnd = NewLastFrame / Main.ModelSetup.C3DFileData.Header.VideoFrameRate;
  AnyIntVar nStep = NewLastFrame - NewFirstFrame + 1;

Because your C3D file has bad marker recording in the last, so I tried not to use the last 20 frames.

Attached find a modified version of your model.

I guess that from now you can run your model well without our support !

Best regards,
Moonki

5

Thank you for your message,

At first, I modified last 20 frames of C3D files that you mentioned has bad marker to right position.
And I edited the code “AnyIntVar LastFrameOffset = 20;” to “AnyIntVar LastFrameOffset = 0;”.
Then I did run the ‘MotionAndParameterOptimizationModel’ process with new C3D files.

I tied to run InverseDynamicModel but the error shown as below has exist and couldn’t finish.
“ERROR(OBJ1) : C:/U…s/d…5/D…p/T…y/A…n/E…s/G…4/JointsAndDriversOptimized.any : JntDriverTrunk : Time, ‘t’, has an invalid value for this interpolation”

I attached whole files to run this program (GaitFullBody_TUT_With_Force_2012_12_5.zip).
AMS is ver 5.1 and AMMR is ver 1.4.

I hope you will be able to solve this problem.
Always appreciate for your kindness.
Akira

6

Hi Akira,

  1. You can try to check your C3D file whether there are some marker drop-outs or not.
  2. If not, then you can try to change these offset values.

Please try to test your models with various efforts first.

If you can’t still solve the problem, then write a question here again.

Best regards,
Moonki

7

Thank you for your message,

So I tried to check C3D files whether there are some marker drop-outs or not. And I found one wrong point.
So I modified that point to correct one.

And I changed offset values as you mentioned.
But I got same problem as before, “ERROR(OBJ1) : C:/U…s/d…5/D…p/T…y/A…n/E…s/G…5/JointsAndDriversOptimized.any : JntDriverTrunk : Time, ‘t’, has an invalid value for this interpolation”.

I attached whole files to run this program (GaitFullBody_TUT_With_Force_2012_12_5_mod.zip).
AMS is ver 5.1 and AMMR is ver 1.4.

Please give your kindness help to solve this problem.
Thank you very much.

Akira

8

Hi,

  1. It seems that you are using old TrialSpecificData.any file in the model.
    Are you developing your model in the latest version?

  2. you ‘always’ use the same name for your C3D file.
    I’m not sure whether you are using new C3D files.
    I’d suggest you to use different names for different C3D files. It will be also good for you to manage different C3D files.

Before uploading new models, please check everything perfectly.

And if you can’t still solve the problem even in that case, then upload your models again.

Best regards,
Moonki