Model FixedArrow defines an arrow that is
shown at the location of its frame_a.
The direction of the arrow specified with vector
n
is with respect to frame_a, i.e., the local frame to which the
arrow component is attached. The direction, length and color of the arrow
can vary dynamically by providing appropriate expressions in the input
fields of the parameter menu.
The quantity
parameter defines what the vector represents, allowing
tools to scale e.g. forces and torques differently in a consistent way.
For the default value RelativePosition the obvious scaling is
1 and the relative position is shown as is.