This script modifies a layer to have a perspective and reflection consistent with that perspective.
This script is not finished. It has not been tested very much, and it is missing major features to come later on.
To install this script, copy it to your scripts folder, then restart Gimp. If you don't know where your scripts folder is, then go to Edit > Preferences > Folders > Scripts.
To run this script, select Filters > Decor > Perspective Reflection.
Feedback is appreciated.