improvements in 3D Camera Tracker in After Effects CC (12.0)
(For a complete list of what’s new and changed in After Effects CC (12.0), see this page.)
In After Effects CC (12.0), we have made a couple of small but very useful improvements to the 3D Camera Tracker effect: the ability to delete track points to isolate the tracking to relevant image data and the ability to set a ground plane and origin.
ground plane and origin in 3D Camera Tracker effect
You can now define a ground plane (reference plane) and origin–i.e., the (0,0,0) point of the coordinate system–within the 3D Camera Tracker effect.
Use the 3D Camera Tracker effect as usual to analyze a scene, and then select a set of tracking points, which causes the bullseye target to appear, showing the plane defined by the selected tracking points. You can optionally drag the target by its center to reposition it along the plane; when the center is where you want the origin to be, right-click the target and choose Set Ground Plane And Origin. This will not have any visible result, but the reference plane and origin of the coordinate system will have been saved for this scene. After this, any items that you create from within this instance of the 3D Camera Tracker effect will be created using this plane and origin as their basis. This is especially useful when exporting the scene to Cinema 4D.
If you choose Set Ground Plane And Origin again, you’ll get a warning telling you that objects already created using a different ground plane and origin will not be updated to use the new ground plane and origin.
Auto-delete Points Across Time
In the Advanced section of the effect properties, there is a new option: Auto-delete Points Across Time.
If this option is on, when you delete track points in the Composition panel, corresponding track points (i.e., track points on the same feature/object) are deleted at other times on the layer, so you don’t need to delete the track points frame by frame to improve the quality of the track. For example, you can delete track points on a person running through the scene, whose motion should not be considered for the determination of how the camera was moving in the shot. This works for both 2D Source and 3D Solved track points.
You can delete selected track points with the Delete key or by context-clicking and choosing Delete Selected Points.
Note: Even with the new Auto-delete Points Across Time feature, you may instead or additionally define an alpha channel for the layer to prevent the 3D Camera Tracker effect from considering a specific part of the image for the purpose of determining a camera.
This feature is essentially identical to the feature of the same name in the Warp Stabilizer VFX effect.