How to connect imported chair from solidworks with seated human (C3D data)

Hello everyone,

I am using MoCap examples of Plug-in-gait_Simple FullBody. I inserted my own data of C3D file with seated human performing pelvis movement. I have only human data. Chair was created in Solidworks and it was imported in mocap file of seated human. However, there is a problem. I cannot move the human from previous position, because it returns to it when I run analysis, so the main task is to move my chair, but how to it?
I created nodes on pelvis and chair and merge it with revolute joint, however the seat did not move. Maybe someone can advice me about this situation?

Thank you,

Hi @ievale and welcome to the forum!

So when you say you moved the human did you change the load position in the mannequin file?
When you start the simulation the drivers will take over and use the mocap data which is not moved.
So I think you are correct to move seat.

The seat probably has constraints on it which prevents it from moving - you can inspect those from the study information window. If there are any you can set them to be soft kinematic constraints and you revolute joint between the human and chair to be using hard constraints.

Best regards,

Hello, Bjorn,

thank you for the answer.
Finally I adjust chair near the human position. But here is another problem. As I mentioned I created nodes on pelvis and chair and merge it with revolute joint, however when I run kinematic analysis I got an error:
ERROR(OBJ.MCH.KIN3) : AnyMocapModel.any(43) : MarkerTracking.InitialConditions : Kinematic analysis failed in time step 0 : Position analysis is not completed

So it means, that the position of the nodes on pelvis and seat is wrong? Do I need to change the axis of these nodes or something else? Also, the attachment should be done in environment file?

Seated human


Hi @ievale

Did you run the parameter identification before the marker tracking?
It is good practice to place environment objects in the environments file but not strictly necessary.

You should ensure that when you join the chair and human the node coordinate systems align. I think you will get it right by default, but you might need to rotate the nodes if the chair is not orientated correctly.

Best regards