On Thu, 24 Jun 2021, Jeong Dal wrote:

> Now, I am trying to do the same thing using \startuseMPgraphic, but I don’t the correct result yet.
> Using \startuseMPgraphic, and \dorecurse, the code is simpler. But, it seems to me that \startanimation … \stopanimation is not working with \dorecurse{}{} …
> It just list all the graphics.
> Any hint is welcome.

A while back, I wrote some code to easily generate metapost animations. 

https://adityam.github.io/context-blog/post/metapost-animation/

I haven't used it much because I am mostly on linux, and its is a PITA to get an older version of Adobe Reader to work under wine. 

Aditya