Maya Nuke CameraTrack
This bit unfinished
As I have already mentioned, the CameraTracker is the glue that holds together the 3D world, 2D compositing and live action footage. The workflow is, in its least detailed form, is this:
Consider the case of trying to get some live action footage and a Maya animation to 'agree' with each other. Such a case might be a camera moving round a figure against a green screen. This needs to be placed against an enviromant made and animated in Maya.
In preperation you should prepare a simple piece of real-world geometry that can correspond in some way with the Maya enviroemnt. an example might be a desk, or chair. This placeholder geometrty will be modeled in Nuke and will serve to unite the scale of the real-world and 3D world.
- Camera track the live action footage.
- From the tracked camera create a scene. The scenes (virtual) camera will contain tracked data from the live action footage (real) camera. Using the camera's File menu parameter (the little folder icon) export the camera data as a .chan file. A .chan file is a common file format for passing camera motion between applications.
- Make some placeholder geometry based on the contents of the live action footage
- Using the Modeler or any of Nuke's simple geometry nodes, make some simple geometry based on the contents of the live action footage. This can be anything simple, like a desk or chair. It will only serve as a visula cue to esatblsh the position of your Maya geometry and its scale. What form it takes depends upon what you are doing, but it need be no more complex that a cube or even a simple card.
- Export the placeholder geometry
- Use the WriteGeo node with which to write out the placeholder as an .obj file.
- Import into Maya
- Import the geometry and camera into Nuke. Ensure that the focal lenghth of the real-world and virtual camera are the same. Make sure that Maya 'agrees' with Nuke (do a simple playblast in Maya and comp into Nuke). Now make your geomtry and render. Remember to render out any junk masks that are needed.