Get the signed angle from a to b measured about axis, in the range (-PI, PI].
Positive is counter-clockwise when axis points toward the viewer. Only the components of
a and b in the plane perpendicular to axis contribute, so they need not be
perpendicular to it. Returns 0 if either projects to the zero vector.
Unlike angle, this distinguishes the two directions of rotation, which is what
hinge limits and turn directions need.
Parameters
a: readonly[number,number,number]
the first operand
b: readonly[number,number,number]
the second operand
axis: readonly[number,number,number]
the axis to measure the rotation about, assumed to be unit length
Get the signed angle from
atobmeasured aboutaxis, in the range (-PI, PI].Positive is counter-clockwise when
axispoints toward the viewer. Only the components ofaandbin the plane perpendicular toaxiscontribute, so they need not be perpendicular to it. Returns 0 if either projects to the zero vector.Unlike angle, this distinguishes the two directions of rotation, which is what hinge limits and turn directions need.