Motion Capture

What's the Difference from Object Tracking?

In object-tracking, the points must all be rigidly connected to one another, and move around as a group; you need only one camera. In motion capture, the points can all move around independently (arms, legs, facial points), but two cameras are required.

How Many Cameras?

Any number of cameras can be used, there's no particular limit, but you need at least two for motion capture. Adding cameras increases accuracy and working volume, reducing occlusion, but takes more of your time for tracking.

What If Markers Disappear?

SynthEyes checks each camera on each frame for each tracker, computing the best location as long as the tracker was seen by two or more cameras on that frame.

If not, there will be no key on that frame. You should get a usable spline-interpolated path on any few frames where the tracker was hidden.

Mocap Accuracy?

It depends on the camera placement and type. As a rough idea, divide twice the horizontal field of view at the subject by the horizontal camera resolution. With good images and subpixel accuracy, you'll do better. With blur, or nearly adjacent cameras, you'll do worse. Evaluate any arrangement with simple triangulation.

What Projects Is It Intended For?

SynthEyes mocap features have been used for high-volume facial capture.

If you want to make the next Polar Express, you'll want a big, fancy, expensive full-body mocap system. But if you need a bunch of hero shots for an indie film, TV commercial, or demo reel, SynthEyes may be exactly the solution you need.