Breakaway motion-capture tracker hardware.
A motion capture tracking device comprising a base portion including a first alignment feature, a first magnetic element and an attachment mechanism operative to mechanically couple the base portion to a rod, a detachable end cap configured to be removably mated with the base portion, and a plurality of motion capture markers coupled to the end cap. The detachable end cap can include a second alignment feature and a second magnetic element, such that, during a mating event in which the detachable end cap is coupled to the base portion, the second alignment feature cooperates with the first alignment feature to ensure that the base portion and detachable end cap are mated in accordance with a unique registration and the second magnetic feature cooperates with the first magnetic feature to magnetically retain the detachable end cap in physical contact with the base portion upon completion of the mating event.
BACKGROUND OF THE INVENTION
A camera creates a record of a three-dimensional (3D) physical scene with a two-dimensional (2D) image. The image may be recorded on a film or as a digital 2D array of pixel values. Computer-based animation and special effects techniques often involve capturing a series of images of one or more actors (or other objects within a scene) with one or more cameras, each of which can have a different viewing perspective. The images from the cameras can be combined to generate a three-dimensional (3D) graphical representation of the actor(s) and scene that can be applied to an animated character or generate special effects and placed in a computer-generated 3D scene that can be used in the production of video content.
In order for the 3D representation of the actors performance within the scene to be accurate, the actors can wear motion capture suits to enable their movements to be precisely captured. Additionally, the location of each camera must be able to be accurately reproduced. Towards this end, each camera typically includes motion capture tracker objects (e.g., colored or reflective balls) that are attached to the camera (or a device fixed to the camera) so that the camera can be tracked in a motion capture volume. When more than one camera is employed, the arrangement of motion capture tracker objects on each camera is unique so that the cameras can be readily identified and distinguished from each other. At various times the motion
1. A motion capture tracking device comprising: a base portion including a first alignment feature, a first magnetic element and an attachment mechanism operative to mechanically couple the base portion to a rod; a detachable end cap configured to be removably mated with the base portion, the detachable end cap including a second alignment feature and a second magnetic element, wherein during a mating event in which the detachable end cap is coupled to the base portion, the second alignment feature cooperates with the first alignment feature to ensure that the base portion and detachable end cap are mated in accordance with a unique registration and the second magnetic feature cooperates with the first magnetic feature to magnetically retain the detachable end cap in physical contact with the base portion upon completion of the mating event; and a plurality of motion capture markers coupled to the end cap. ||
2. The motion capture tracking device set forth in claim 1 wherein the base portion includes an alignment body comprising the first alignment feature and a collar coupled to the alignment body and comprising the attachment mechanism. ||
3. The motion capture tracking device set forth in claim 2 wherein the first alignment feature comprises a sidewall surface of the alignment body and the second alignment feature comprises a sidewall surface of the detachable end cap defining a recess that aligns with and fits over the sidewall surface of the alignment body. ||
4. The motion capture tracking device set forth in claim 2 wherein the collar includes a generally circular channel extending longitudinally through the collar towards the base portion and further includes a clamping mechanism operable to tighten the collar to mechanically secure the base portion to a rod. ||
5. The motion capture tracking device set forth in claim 4 wherein the clamping mechanism includes a first threaded screw hole perpendicular to the generally circular channel and a screw that can be threaded into the screw hole to tighten the clamping mechanism around the rod. ||
6. The motion capture tracking device set forth in claim 1 wherein the end cap includes a plurality of threaded holes distributed around an outer periphery of the end cap. ||
7. The motion capture tracking device set forth in claim 6 wherein each motion capture markers in the plurality of motion capture markers includes a post having a first end with threads operable to couple the post to one of the plurality of threaded holes and a motion tracker object coupled to a second end of the post. ||
8. The motion capture tracking device set forth in claim 7 wherein each motion tracker object attached to the second end of a post in the plurality of motion capture markers comprises a retro-reflective motion tracker ball. ||
9. The motion capture tracking device set forth in claim 1 wherein the base portion and the end cap are each made from a plastic material and at least one of the first magnetic element or the second magnetic element comprises a magnet and the other of the first magnetic element and the second magnetic element comprises either a magnet or a plate comprising a magnetic material. ||
10. A motion capture tracking device comprising: a base portion, a detachable end cap coupled to the base portion and a plurality of motion capture markers coupled to the end cap; the base portion comprising: (i) an alignment body having first and second opposing surfaces and a sidewall extending fully around an outer perimeter of the alignment body between the first and second opposing surfaces; (ii) one or more base portion magnetic elements coupled to the alignment body; and (iii) a collar coupled to and extending away from second surface of the alignment body, wherein the collar includes a generally circular channel extending longitudinally through the collar and a clamping mechanism operable to tighten the collar to mechanically secure the base portion to a rod; and the detachable end cap comprising: (i) a front plate; (ii) a sidewall extending away from the front plate towards the base portion and defining an end cap recess having an inner perimeter such that the alignment body of the base portion can be fitted within the recess and mated with the detachable cap; and (iii) one or more end cap magnetic elements coupled to the detachable end cap and operable to cooperate with the one or more base portion magnetic elements to magnetically secure the end cap to the base portion when the end cap recess is fitted over the alignment body. ||
11. The motion capture tracking device set forth in claim 10 wherein an interface between the alignment body sidewall and the front surface extends fully around the front surface and is tapered or curved. ||
12. The motion capture tracking device set forth in claim 10 wherein the base portion and the end cap are each made from a plastic material. ||
13. The motion capture tracking device set forth in claim 10 wherein the clamping mechanism includes a first threaded screw hole perpendicular to the generally circular channel and a screw that can be threaded into the screw hole to tighten the clamping mechanism around the rod. ||
14. The motion capture tracking device set forth in claim 10 wherein there is only one orientation in which the alignment body of the base portion can only be fitted within the recess and mated with the detachable end cap. ||
15. The motion capture tracking device set forth in claim 10 further comprising an eyelet coupled to the end cap. ||
16. The motion capture tracking device set forth in claim 10 wherein the detachable end cap further includes a plurality of threaded holes spaced apart along an exterior surface of the sidewall and each of the plurality of motion capture markers is coupled to the detachable end cap by one of the threaded holes in the plurality of threaded holes. ||
17. The motion capture tracking device set forth in claim 16 wherein each motion capture marker in the plurality of motion capture markers comprises a post having first and second opposing ends, the first end including a threaded portion enabling the post to be screwed into one of the plurality of threaded holes, the second end having a motion capture tracker object attached thereto. ||
18. The motion capture tracking device set forth in claim 17 wherein each motion tracker object attached to the second end of a post in the plurality of motion capture markers comprises a retro-reflective motion tracker ball. ||
19. A motion capture tracking device comprising: a base portion having an alignment body having an exterior perimeter sidewall surface that defines a polarized mounting surface; one or more first magnetic elements coupled to the alignment body; and a collar coupled to and extending away from the alignment body, the collar having a generally circular channel extending longitudinally through the collar towards the alignment body and including at least one fastener hole extending into the collar at an angle perpendicular to the generally circular channel and a fastener operable to tighten the collar around an object inserted into the generally circular channel to secure the base portion to the object; an end cap magnetically attachable to the base portion, the end cap having a front plate; a sidewall extending away from the front plate and defining an end cap recess opposite the front plate and having an inner perimeter such that the end cap can be fitted over the alignment body and mated with the base portion; one or more second magnetic elements coupled to the end cap and operable to cooperate with the one or more first magnetic elements to magnetically secure the end cap to the base portion when the end cap recess is fitted over the alignment body; and a plurality of threaded holes spaced apart along an exterior surface of the sidewall; a plurality of motion capture markers coupled to the end cap, each motion capture marker in the plurality of motion capture markers comprising a post having a first threaded end that is coupled to one of the threaded holes in the plurality of threaded holes, a second end opposite the first end, and a motion tracker ball coupled to the second end; wherein at two or more of the plurality of motion capture markers have posts of different lengths. ||
20. The motion capture tracking device set forth in claim 19 wherein the exterior perimeter sidewall surface of the alignment body and the inner perimeter of the end cap sidewall are sized and shaped such that the end cap can be mated with the end cap in a single orientation.