Three-dimensional motion capture

A system comprising:

• one or more support structures configured to be coupled to an actor whose motion is to be tracked by one or more cameras, each of the one or more support structures being a band having a plurality of marks each of which is positioned in a respective region of the band that visually contrasts with a corresponding motion capture mark such that when coupled to the actor, the band of each of the one or more support structures is wrapped around a predetermined body part of the actor, the band being of sufficient rigidity such that, in response to movement by the actor, each of the plurality of marks on the band maintains substantially fixed distances from every other mark on the band, the plurality of marks being positioned on the band such that, when wrapped around the predetermined body part of the actor, fewer than all the marks on the band are visible within a field of view of any one of the one or more cameras;
• one or more processors configured to perform operations comprising:
• associating respective positions of the one or more support structures coupled to the actor to respective positions of corresponding virtual support structures for a virtual skeleton associated with the actor, wherein the plurality of marks on each of the one or more support structures coupled to the actor substantially correspond in position to a plurality of virtual marks on each of the virtual support structures;
• receiving a frame associated with one or more camera views that depicts marks on the one or more support structures coupled to the actor tracked by the one or more cameras and selecting one or more marks from among the marks depicted in the frame;
• calculating ray traces extending from corresponding ones of the one or more camera views through the selected one or more marks;
• and
• determining an orientation of the virtual skeleton associated with the actor by aligning one or more of the virtual marks corresponding to the selected one or more marks to substantially lie on the calculated ray traces as constrained by joints and movement possibilities of the virtual skeleton, wherein each additional aligned virtual mark serves as an additional constraint for determining the orientation of the virtual skeleton associated with the actor.

A computer program product, encoded on a non-transitory computer-readable medium, operable to cause data processing apparatus to perform operations comprising:

• associating respective positions of one or more support structures coupled to an actor whose motion is to be tracked by one or more cameras to respective positions of corresponding virtual support structures for a virtual skeleton associated with the actor, each of the one or more support structures being a band having a plurality of marks each of which is positioned in a respective region of the band that visually contrasts with a corresponding motion capture mark such that, when coupled to the actor, the band of each of the one or more support structures is wrapped around a predetermined body part of the actor, the band being of sufficient rigidity such that, in response to movement by the actor, each of the plurality of marks on the band maintains substantially fixed distances from every other mark on the band, the plurality of marks being positioned on the band such that, when wrapped around the predetermined body part of the actor, fewer than all the marks on the band are visible within a field of view of any one of the one or more cameras, wherein the plurality of marks on each of the one or more support structures coupled to the actor substantially correspond in position to a plurality of virtual marks on each of the virtual support structures;
• receiving a frame associated with one or more camera views that depicts marks on the one or more support structures coupled to the actor tracked by the one or more cameras and selecting one or more marks from among the marks depicted in the frame;
• calculating ray traces extending from corresponding ones of the one or more camera views through the selected one or more marks;
• and
• determining an orientation of the virtual skeleton associated with the actor by aligning one or more of the virtual marks corresponding to the selected one or more marks to substantially lie on the calculated ray traces as constrained by joints and movement possibilities of the virtual skeleton, wherein each additional aligned virtual mark serves as an additional constraint for determining the orientation of the virtual skeleton associated with the actor.