Non-horizontal foot contacts

[Saeed-Mansouri]

Dear Dr. Caron,

You stated in #12 (comment):

On a side note, if foot contacts are not horizontal, we can rectify them using the analytical projection of their contact wrench cone described in Section IV of this paper. I didn't implement this in this controller since non-horizontal foot contacts were not part of our use case.

Would you please explain which parts of the lipm_walking_controller package don't work if the foot contacts are non-horizontal?

[stephane-caron]

In the context of #12 (comment) we were discussing about the ModelPredictiveControl class used for walking pattern generation. That's the component in this controller that assumes non-coplanar but horizontal contacts.