Projection warping should be viewer position independent (within a limited scope), only relying on the position of the projector and the screen. Some home theater projectors which already do this to an extent. And there are some famous public performances where video is projected onto a building and warped to match the contours in such a way as to give a convincing 3d effect (Example: https://www.youtube.com/watch?v=gJ_5sDvAlNY). You can perform this kind of projection warping on a raspberry pi.
