## Bug #1043

Updated by A. Tuleu almost 12 years ago

Modelisation of wrench seems wrong in RCI. Wrench store Torque as quaternion. However queternion are for storing rotation, that leaves in space SO (3). SO(3). Rotation are not additive (you only combine them).

However a torque is a simply a linear vector living in space R^3 therefore, you should store them in this space, and not as quaternion.

Wrench live in a more complex state, since they are (naively) defined by 9 dimension :

* a translational force

* a rotational force

* a point of origin

but actually these 3 values are bind together by the rule of transport.

However a torque is a simply a linear vector living in space R^3 therefore, you should store them in this space, and not as quaternion.

Wrench live in a more complex state, since they are (naively) defined by 9 dimension :

* a translational force

* a rotational force

* a point of origin

but actually these 3 values are bind together by the rule of transport.