public float dot(Quaternion q) {
        return w * q.w + x * q.x + y * q.y + z * q.z;
    }
Returns the dot product with the argument. The current instance is
unaffected.

<p>This method can be used to quantify the similarity of 2 normalized
quaternions.

@param q the quaternion to multiply (not null, unaffected)
@return the dot product
jme3-core/src/main/java/com/jme3/math/Quaternion.java