I worked on two compositions in After Effects files (a 6 second and a minute composition). How can I merge the compositions in a new composition so that the minute long composition will follow immediately after the 6 second composition?
I think you can "place embedded"? (File->Place) If not, you can open them both at the same time, then literally drag one tab/file onto the other. It works in all my other Adobe products, so hopefully in Ae as well.
I also found this online:
Save your original After Effects file.
Go to File/Save/Save A Copy..
Open the Copy file then customize the template with your new photos or videos. Be sure to Save when you’re done.
Now open the original After Effects file.
Go to File/Import/File.. Select the Copied After Effects file (it will have an .aep file extension) and click Open.
You’ll see in the Project Panel that After Effects has imported the Copied After Effects file as a folder. Inside this folder you’ll find all the compositions, solids, and any assets used in this After Effects file.
Now here’s the fun part! With your Render Comp timeline selected to go the Composition menu then select Composition Settings. In the pop up window go to the Duration section and add some time to the composition’s duration. This setting will give you more space (and therefore time) in the timeline so you can add more scenes or placeholder compositions.
Now you’re ready! In the Copied After Effects file’s folder select the comps you want to use then drag and drop them into your final Render composition. Move them around in the timeline as needed.
I think your key is Import and "Add time" to your comp. I always drag my stuff into libraries panel, then just pull it out of that library from my other file.