math - Spherical interpolation : how to rotate an object backwards? -


i rotating transform following line:

quaternion.slerp(quaternion qbegin, quaternion qend, float deltatime);

the spherical interpolation uses shortest rotation between qbegin , qend.

sometimes, need make interpolation "backwards", longest rotation between qbegin , qend.

i achieve cutting big rotation consecutive smaller ones, prefer have proper mathematical answer rather "fix" approach.

my question : how rotate object backwards elegance ?


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