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Stereoscopic Object Tracking
SynthEyes can perform stereo object tracking, where the same rigid object is tracked from both cameras. (It can also do motion capture from stereo imagery, where the objects do not have to be rigid, and each feature is tracked separately.) Or you can do single-eye object tracking on a stereo shot, if the object moves enough for that to work well.
To set up the stereo moving-object setup, do a Shot/Add Moving Object when a stereo shot is active. You will be asked whether to create a regular or stereo moving object. The latter is similar to adding a moving object twice, once when each camera (left and right) is selected as the main active object (the currently-selected camera is used as the parent when a new object is created), except that SynthEyes records that the two are linked together. Each object will have the Stereo solving mode.
An object can only be in one place at a time: there should only be a single path for the object in world space, the same path as seen in the left and right cameras, just like each 3-D tracker pair only has a single location. The world path depends on the camera path, though! This creates challenging “what comes first” issues. Object solves always start with an initial camera-type estimate, before being converted to an object- type solve, and that is what happens with object solves as well.
Simple object solves start out with two separate motion paths, one for the “left object” and one for the “right object.” As the camera path becomes available, additional constraints are applied that force the left and right paths, in world space, to become practically identical by adjusting the camera and object positioning.
Because of this inherent interaction, it is wise to work on the camera solve first, before proceeding to the objects.
Warning : if you disable the cameras while you work on the object, you'll need to lock the field of views to avoid creating a mismatch. Alternatively, set the cameras to Refine mode.
You can use one or more axis locks on the camera and/or object, typically once you've got the initial solves (and then set everything to Refine mode). For stereo cameras and objects, place the locks on the dominant camera or object. Locks on the secondary camera or objects will be ignored!
To perform motion-capture style tracking in a stereo shot, after completing the camera tracking, do an Add Moving Object, then set the solver mode for the object(s) to Individual Mocap. Add stereo tracking pairs on the moving object, and each pair will be
solved to create a separate independent path. See the online tutorial for an example, and see the Motion Capture section of the manual.
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