It works as it always has - AE stores references to the PSD layers, not the full document. Importing as a comp is merely assisting in retaing the positioning and structure of the original file and translate it to native AE layers and comps. Any additions after the initial import will therefore have to be imported separately.
But it's very inconvenient if the number of new layers of more than ten. I often meet with a similar problem. Does not anyone come across this?...
There are two solutions to your problem. One, rename the new Photoshop file and import it as a new comp and then replace the layers you have already animated with the same layers in the new comp by a simple cut and paste from old comp to the new, or two, copy and paste the new layers from the new comp into the original comp.
Not rocket science, just common sense.
If your standard workflow involves adding a bunch of layers to an existing Photoshop file then someone needs to rethink the workflow. It's not very efficient.
Thanks for the answers, but these methods are good only if the number of new layers of not more than ten, otherwise it will be a monkey work.
I don't follow you. If you have 500 new layers to animate, then you have to import 500.
And that's what you get if you import a new PSD and add it to your project. Sure animating 500 layers is work, but the real problem is not new layers, it's your workflow.
If you're adding 30 or 40 layers to a PSD file and they are not moving, then dropping in a nested Photoshop composition is a one click deal. The workflows that I suggested allows you to keep all of your old animation and add layers with just a few simple steps. Even a more automated way to do that would still leave you all the new layers to animate. Even if AE recognized all of the new layers and then organized them in the project window in the same folder and in the same way a Photoshop or illustrator file is imported as a composition, you would still have to arrange them in your composition because compositions only reference the assets in the project window. What you're asking is the import function to do is remember everything you did in composition and figure out where and what you want done with the new assets you have added to the project.
I understood you. I will change my workflow.