So the track used for chris’s model and my spinning top had some issues. You can see them at 0.11 and 0.15 in the video below.

The model appears to get smaller for one frame and lager in a few others.

So i took a look at what was happening to the camera in Maya.

Taking note of what second the problem occurred it did a little maths to work out around what frame it was happening. So the 11 th second x 25 frames a second suggested the problem was around  frame 275 observing frame by frame i spotted it at 337. I also did the same for the problem around the 15th second and this is what i found.

Now there are a few reasons this could be happening. When you import the exported match move camera, the camera is still editable, so i could have accidentally scrolled the camera forward thinking i was in perspective view and it has auto keyed. This can be easily prevented by locking all the attributes of the camera in Maya. But It could also be a calibration problem in Matchmover.

The red areas in the tracks mean that Matchmover isn’t confident in the quality of the track. It could be these that confuse the program and calculate the camera in the wrong place. You can eliminate these red spots by placing the tracking box back in the right place manually and tracking forward from there. If it happens again, just pick up the track again from the red point. Having little or no red on your tracks will give you a good camera solve ( creates a camera in 3D space)

I tried to put the camera problem right in maya by zooming the camrea in and out and it seemed to work. There is just one more thing that was an issue.

At approximately 0.14 in this playblast the camera actually goes through the face of the model. So this is something you need to be aware of when filming, how big and what space would the model take up if it was actually in that live environment to avoid this happening. Or the model could have been moved slightly back in the Maya scene to prevent this from happening.