I'm not fully clear on what you're trying to do, but just about anything is possible!
If you want to morph a foreground element without affecting its background, you'll need to separate the foreground from the background (probably by masking) and clean up the background in any areas where the changing foreground would reveal it (probably by cloning).
If you want to do it all inside a 360, you'll need to make sure you maintain the correct distortion and mind the seam.
Hi Walter , and thank you for the quick answer !
I think you get what i wanted to do and i'll try with what you told me.
(it's like rotoscoping no?)
yet I'll try to be as clear as possible.
with multiple photograph of a cityscape, I want to create a 360 cylindric view (without zenith) where some elements from foreground to background (skyscraper,shop,river,bridge,...) are replaced at different moment using morphing by others, external elements.