I know that if q1 and q2 indicate rotations, then q2q1 represents the composite rotation of q1 followed by q2.

but what about addition?

-- luis opazo (luisopazo@hotmail.com), March 05, 2004

Answers

Hello Luis:

Think of it as a combination of scalar and vector addition. The scalars add together like scalars always do, and the vector addition leads to a new vector pointing a new way (unless the vectors are collinear).

Only a particular subgroup of quaternions are about rotations, those that are unitary (have a norm of one). If the norm is not one, then there is a rotation along with an expansion or contraction.

doug

-- Douglas Sweetser (sweetser@alum.mit.edu), March 07, 2004.