CodePen - Motion along a closed path, arbitrary start point

There is no pre-defined way in SVG1.1 to define an offset for <animateMotion>. However, you can mimic this behaviour by using key points and times, jumping from the end to the beginning of the path instantaneously.

The math to calculate keyPoints and keyTimes for the forward movement is as follows:

keyPoints: (startPosition); 1; 0; (startPosition)
keyTimes: 0; (1 - startPosition); (1 - startPosition); 1

For the reverse motion, it is:


  keyPoints 
    (startPosition)
    0
    1
    (startPosition)
  keyTimes 
    0
    (startPosition)
    (startPosition)
    1

In both cases startPosition is a decimal between 0 and 1 representing the proportion of distance along the path. You also need to explicitly set calcMode="linear" for the key values to have an effect.

Now if only there was a way to get text on a path to wrap around a closed path.