How to crate a Body orientation for rotating a 3D vector parallel to a given arbitrary vector

[Andrea Danzi]

I need to instantiate a BodyOrienter that rotates the axis of my "Body" parallel to a given arbitrary vector.

How can I calculate the three successive angles required to rotate the coordinate system parallel to the given vector?

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Andrea

[Andrea Danzi]

I did this way:

• calculate the angle between vector1 and vector2
• rotate around the axis defined by vector1.cross(vector2)

v_cross = vect1.cross(vect2)
v_dot = vect1.dot(vect2)

if v_dot == 0:
    v_angle = pi/2.
else:
    v_angle =acos(   v_dot / ( vect2.magnitude()*vect_base.magnitude()  ) )
R = N.orient_new_axis('R', v_angle,v_cross)

[Jason Moore]

Given two vectors, there is not a unique solution of euler-like angles that you can solve for that relates the two vectors. If you have a desired set of axes to rotate about you can formulate three non-linear equations from the transformation. You'll like have to solve this numerically though, with a good initial guess. I don't think solving it analytically is trivial (or necessarily possible).

Jason

moorepants.info
+01 530-601-9791

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