animateMotion and animateTransform
If animateMotion and animateTransform act on the same element,
the animateMotion is a supplemental transformation matrix onto the CTM
of the animateTransform.
The rotation related to the animateMotion attribute rotate is
a supplemental transformation matrix onto the CTM and the animateMotion
translation.
What does it mean for the order the transformations are applied?
This can be simulated with nested g elements.
The test case here is a group with a blue rectangle and a circle.
The circle is centered at the origin.
This group is additionally skewed with an animateTransform.
The intended effect of the rotate attribute value 'auto' is here to
align the rectangle along the path, the larger part of the rectangle in
motion direction.
The motion path is given in gray for comparison.
A red comparison has to be completely covered,
therefore not visible, else an error has occured.
transform comparison
test case