Basic question :
I import a Ai file as composition, then I change some drawing in Ai and come back to Ae.
elements moved because they keep the old Anbchor point. How to prevent that and make the update like if I just imported after the last update?
Or : how can I update and keep the file in Ae like in Ai?
Thanks a lot.
You can't. These are limitations in the AI format itself. The transform info for objects is not persistent and dynamically re-calculated in relation to the artboard. Since AE doesn't know anything about this, it will simply retain the anchor point like when it was first imported. You can only re-import the AI file fully and then hope that some copy&paste magic will save your day.
1. Make sure your Ai document size matches your Ae frame size - eg: 1920x1080.
2. Import as Composition (NOT composition - retain layer sizes).
when you want to make a modification in Ai...
3. find the modified layer in the project panel folder. Right click > Reload footage.