Motion capture using synchronized and aligned devices

A motion capture system comprising:

• a primary clock configured to repeatedly generate and output, at a frame rate, a primary clock signal that conveys when video frames start;
• a first camera configured to capture light within a first set of wavelengths comprising the visible light spectrum and generate images from the captured light, wherein the first camera includes a first shutter and is operably coupled to receive the primary clock signal and activate the first shutter in a fixed phase relationship with the primary clock signal to capture a first set of images at the frame rate;
• a synchronization module operably coupled to receive the primary clock signal from the primary clock and configured to generate and output a synchronization signal offset from and in a fixed relationship with the primary clock signal;
• a second camera configured to capture light within a second set of wavelengths comprising infrared light and generate images from the captured light, wherein the second camera includes a second shutter and is operably coupled to receive the synchronization signal and activate the second shutter in fixed phase relationship with the synchronization signal to align the second camera with the first camera and capture a second sets of images at the frame rate;
• and
• a third camera configured to capture light within the second set of wavelengths and generate images from the captured light, wherein the third camera includes a third shutter and is operably coupled to receive the synchronization signal and activate the third shutter in fixed phase relationship with the synchronization signal to align the third camera with the first camera and capture a third set of images at the frame rate;
• wherein:
• the motion capture system further comprises a light source and a driver configured to generate pulses of light at a wavelength within the second set of wavelengths,
• the synchronization signal received by the second and third cameras is the first synchronization signal, and
• the driver is operatively coupled to the synchronization module to receive the second synchronization signal, and in response to the second synchronization signal, turn the infrared light source ON and OFF to generate short pulses of light synchronized with the frame rate and in a fixed relationship with the second synchronization signal to align the pulses of light generated by the infrared light source with the image capture sequence of the second camera such that the infrared light source only projects light for a portion of each frame.

A computer-implemented method of capturing motion with a motion capture system, the method comprising:

• generating and outputting, at a frame rate, a primary clock signal that conveys when a video frame starts;
• controlling a first camera with the primary clock signal to capture a first plurality of images of an actor in a performance area, wherein the first camera is operable to capture light at wavelengths in a first spectrum comprising visible light;
• emitting infrared light from an infrared light source at towards the actor in the performance area;
• generating a first synchronization signal offset from and in a fixed relationship with the primary clock signal;
• generating a second synchronization signal offset from and in a fixed relationship with the primary clock signal;
• controlling a second camera with the first synchronization signal to align the second camera with the first camera and capture a second plurality of images of the actor concurrent with capturing the first plurality of images of the actor, wherein the second camera is operable to capture light at infrared wavelengths;
• and
• controlling the infrared light source to turn the light source ON and OFF thereby emitting pulses of infrared light into the performance area based on the second synchronization signal to synchronize the pulses of infrared light with a shutter of the second camera such that infrared light is only projected into the performance area for a portion of each frame.