Another area of uncertainty regarding to-animation is how a repeated to-animation should behave when accumulate it set to
sum. Should the animation build like other animations or repeat it’s normal to-animation?
Here is a simple example:
<circle fill="red" stroke="black" r="20">
<animateTransform attributeName="transform" type="scale"
to="2" dur="0.75" repeatCount="4" accumulate="sum"
And in your browser:
In Batik the to-animation repeats, and in Opera it just keeps growing. So which is right?
It’s not spelled out in the spec, but fortunately this has been addressed in SMIL3 which prefers the behaviour of Batik, i.e. the accumulate attribute has no effect. Cumulative animation of to-animation is not defined.