Non Uniform Scaling
Posted: Tue Jul 30, 2019 1:43 am
As detailed in this video, we make use of four types of markers:
1) Anatomical markers
2) Tracking markers
3) Virtual markers
4) Model markers
Anatomical and Virtual markers (middle points, projections, etc. of anatomical markers) are used for scaling the model non-uniformly. I have few queries regarding this:
1) Do I need to compute the virtual markers and append to *.trc file before importing it to OpenSim?
2) Can you please point me to some documentation that has guidelines for selecting these virtual points.
3) Scaling tool computes the scaling factor using the distances between selected marker pairs in the experimental and model marker set. In case we are using more than one pair
3a) Are they weighted equally to compute the final scaling factor?
3b) Is the user responsible for ensuring that the marker pairs points in the same direction?
3c) Is the user responsible for ensuring that the scaling factors point to X, Y, and Z directions of the body definition model?
4) Can you please point me to some documentation/examples which involve non-uniform scaling.
5) Can you also please point me to an example which uses regression to compute functional joint center (a virtual marker).
I will be analyzing Sit to Stand motion.
I apologize for a long list of queries in a single post.
Thank you
1) Anatomical markers
2) Tracking markers
3) Virtual markers
4) Model markers
Anatomical and Virtual markers (middle points, projections, etc. of anatomical markers) are used for scaling the model non-uniformly. I have few queries regarding this:
1) Do I need to compute the virtual markers and append to *.trc file before importing it to OpenSim?
2) Can you please point me to some documentation that has guidelines for selecting these virtual points.
3) Scaling tool computes the scaling factor using the distances between selected marker pairs in the experimental and model marker set. In case we are using more than one pair
3a) Are they weighted equally to compute the final scaling factor?
3b) Is the user responsible for ensuring that the marker pairs points in the same direction?
3c) Is the user responsible for ensuring that the scaling factors point to X, Y, and Z directions of the body definition model?
4) Can you please point me to some documentation/examples which involve non-uniform scaling.
5) Can you also please point me to an example which uses regression to compute functional joint center (a virtual marker).
I will be analyzing Sit to Stand motion.
I apologize for a long list of queries in a single post.
Thank you