I've searched around on the COW and I've watched the Video Copilot tutorials using Vanishing Point, but nothing seems to correspond to what I was trying to achieve on a recent project, so I'm wondering whether I missed a trick with VP, or whether I was just barking up the wrong tree.
I had some footage of an office interior (large, open plan space) in which I wanted to add some titles. The idea was to make it look as though the text was moving across the ceiling and walls of the room, so I wanted to add some 3D layers which matched. Rather than add some layers and fiddle around with the camera position until they matched by eye, I thought thought that Vanishing Point might be a simpler solution, so I exported a still to Photoshop, added a couple of grids (one vertical for the back wall, and one horizontal for the ceiling) and saved out the .vpe data. Once imported into AE, however, if I superimposed the VP comp over the footage, the camera position never matched and, if I adjusted the camera manually, the perspective and scale were still a bit off - close, but not close enough. Although I didn't actually intend to use the 3D images exported from Photoshop, they made it clear that the geometry of the 3D layers didn't match the original footage.
The interior wasn't particularly complex - the camera was pretty much perpendicular to one wall, with a wide-ish angle lens (I'm guessing, I wasn't at the shoot), but I never managed to get a match using VP. In the end, as time was getting short, I just placed the 3D layers by eye, but I can't help feeling that I may have missed something in the Vanishing Point settings that might have made it work. If anybody has used VP to do something similar, I'd be grateful for any tips... or maybe it just isn't designed to do what I was trying to do?