Joint that has a spherical joint on each of its two ends.
The rod connecting the two spherical joints is approximated by a
point mass that is located in the middle of the rod. When the mass
is set to zero (default), special code for a massless body is generated.
In the following default animation figure, the two spherical joints are
represented by two red spheres, the connecting rod by a grey cylinder
and the point mass in the middle of the rod by a light blue sphere:
This joint introduces
one constraint defining that the distance between
the origin of frame_a and the origin of frame_b is constant (= rodLength).
It is highly recommended to use this joint in loops
whenever possible, because this enhances the efficiency
considerably due to smaller systems of non-linear algebraic
equations.
It is sometimes desirable to compute the rodLength
of the connecting rod during initialization. For this, parameter
computeLength has to be set to true and instead one other,
easier to determine, position variable in the same loop
needs to have a fixed attribute of true. For example,
if a loop consists of one Revolute joint, one Prismatic joint and
a SphericalSpherical joint, one may fix the start values of the revolute
joint angle and of the relative distance of the prismatic joint
in order to compute the rodLength of the rod.
It is not possible to connect other components, such as a body with mass
properties or a special visual shape object to the rod connecting
the two spherical joints. If this is needed, use instead joint Joints.UniversalSpherical
that has this property.
CONNECTORS
