Hello!!!
I'd want to execute a mel script in even time an animation.How can I do that???
A bit doepending on what your doing you either want a expressiion ofr a scriptjob. Scripjobs jsuualy fine if you just change something for a gui.
But to be honest you realy in all likelyhood dont want to do this as a animation tool. You may think you do but its not something you usualy want in the end. Its one of those things that is a good idea when you firstt think of it untill you actualy start to implement it,
Se if a script executes every frame then the script needs to be able to cope with moving about in the timeline, so the script would need to account for what the state is and how to change if one jumps form frame 100 to frame 57 as wall as from frame 1 to 2, tehn 2 to 1 and so on.
So for example a frame by freame executed script that creates a sphetre on each frame, its nothing you want to do. totaly honestly beacsue itd just keep adding those speheres scrub forward or backward.
But again it all depends on whatkind of use you have and if it has sideffects or not. And how fast it executes because you dont need much fumbling to make something teht runs 60 fps to start working at aslow pace of 0.1 fps.
Anyway it would help me to help you if you actualy told what you NEED this for. Usualy yioud only truly do this IF and only if you have NO OTHER POSSIBLE ALTERNATIVE. or you know the exact implications.
But you need no mel fror turning object based on their proevious position pure expression syntax is enough (note mel is not equal to expressions)