Part 4 - Adjusting your 3d scene to the voodoo_cam

Voodoo Camera Tracker is a very powerful free match mover. The only real issue I see with using it is aligning the voodoo_cam to your scene. After a few weeks of trying various ways including camera matching the scene and aligning the voodoo_cam to the matched cam, creating a matched cam and aligning it to the voodoo_cam using rotation and position constraints to animate the matched cam, etc. Nothing worked. What I have found that DOES work is to create either a truly Matched Camera using 3ds Max's Camera Match utility or simply aligning a camera by eye-balling it, then aligning the WHOLE scene to the voodoo_cam. There are a couple of issues to be addressed before trying this method:

If you choose to use the Camera Match utility in 3ds Max, you will have to change the FOV of the matched cam to that of the voodoo cam. I've found its best to go ahead and create the 3d scene will all geometry in place, set up the camera points and match the camera.

IMPORTANT: Change the FOV to that of the voodoo_cam and hit Modify Camera in the Camera Match utility. Then truck the camera to or from so that the camera point helpers re-align with your reference geometry. The next step is to LINK all scene geometry to the matched_cam.

Now run the exported Voodoo Camera Tracker MAXscript to generate the voodoo_cam and it's feature point helpers. Select the matched_cam and align it to the voodoo_cam on all three axis. Make sure all Position and Orientation check boxes are checked as well as Scale.

You can now change the perspective viewport to the voodoo_cam, set up your Environment Background and Viewport Background to your source video or .tga sequence and render. Note: Remember, if your source video was captured at 29.97fps and your .tga sequence was converted at 30fps, you'll need to convert your source video to 30fps or use the .tga sequence as your final Environment Background for rendering.

If you need to add geometry or move geometry around at this point, you should always use LOCAL coordinates on the geometry when adjusting it since it will no longer be aligned parallel or perpendicular to the world axis. If this is an issue, you can create a grid helper and align it to the ground plane (assuming you have one) of your 3d scene, then things should be smoother to edit.