This effect will work best with a scene that contains a lot of depth. Since the parallax effect will be enhanced the more you see of the floor, the ceiling and the walls, I do recommend using a fairly wide angle shotCreate a new composition.
One important thing we need to configure before we get started is the shadow quality of our composition. The projection of our footage layer is technically its shadow so we want to make sure we set the shadow quality to very high, otherwise we might not see much more than a blurry mess.
For this, open your composition settings, go to the 'Advanced' tab and click on 'Options...'. Set the 'Shadow Map Quality' to something large, like 4000.
For the first scene, I have an image here that I took in a car park.
Add this image into your composition as a new layer.This layer will be projected onto the 3D layers we will set up to remodel the geometry of the scene.
Because we will eventually turn it into a 3D layer and disable its visibility, let's duplicate it and set the copy up as a Guide Layer. Set the opacity of the guide layer to something like 30%.
A guide layer will be visible in the composition but won't be rendered as part of the final effect. We just want to add it so we can still see our scene once we disable the visibility of the original garage layer.Now turn the original garage layer into a 3D layer.
Create a new camera. Set up the camera properties, especially the focal length, to match the camera you used to shoot your scene as precisely as possible. I used a focal length of 35mm.
Create a new spot light. Set the following properties
The most important thing to check is the 'Cast Shadows' option. Remember we will shine this light through our garage image to project the shadow of the garage image - the projection - onto the 3D layers. If the light does not cast shadows, the effect will not work.