I tracked a sequence of images and want to add a box to the tracked scene. All works well, and in the 3D view, if I change the current frame, the box looks aligned to the movie, which I use as a background.
When compositing, I have a RenderLayer node and the movie node combined using "over alpha". This works, but in the viewer, the rendered cube is at a fixed location (doesn't move with the scene), as it it's pinned to a single frame. The 3D view still works, and as I slide the current time, the cube moves with the movie.
Attaching a screenshot where the cube is aligned (next to the mouse) in the 3D view (bottom right), but not in the composite viewer (bottom left).
To make things more clear, here's a comparison of the 3D view (on the right) and the composite result view (on the left). First, on frame 20:
Now on frame 50:
And finally on frame 220:
In the composite output view, the cube is stationary while in the 3D view it's "moving" with the tracked camera.
Here's the blend file: comp_room2.blend