Not off the bat. You can use the Comp Resizer script that comes with AE to do some of that, but many effects that use absolute values/ coordinates will have to be adjusted as will things like masks, placement of shape layers, text layers and so on. Of course some of that again could be automated/ facilitated with additional scripts or applying expressions that convert value ranges, but there will always be manual labour involved.
Portrait to landscape? Precisely do you seek to do:
1) rotate the work you've already done,
2) somehow redistribute the layers, position points, etc. of your work into a different aspect ratio or
3) something else
Your query is confusing, and clarification will help people be more specific.
Well, I have a particular built light band zipping through the frame. The composition was 1280x720. I want to change it to 720x1280 and keep all my other settings as is. In other words, grab and migrate all the layers etc and move them around to fit the new comp format. I may be overthinking this. I could render out what I have with an alpha and do a new compostion I suppose but then I'd be stuck with that comp as it is. I was hoping there was a magic button/one step process.
Thank you all for your responses.
Here is a quick visual example. See how the particle effect is retaining the old comp format? Is there an easy way to change that to fit the new without rebuilding the particular?
You can nest the 16x9 comp in the 9x16 comp and rotate it 90 degrees, then add whatever you want.
Thanks. I'll give it a shot.