DETERMINING AND TRACKING MOVEMENT

Apparatuses, components, devices, methods, and systems for determining and tracking movement are provided. An example apparatus that includes a position indicating system having a first light emitter positioned and oriented to emit light in a first direction, a second light emitter positioned and oriented to emit light in a second direction, the second direction being collinear with and opposite to the first direction; and a third light emitter positioned and oriented to emit light in a third direction, the third direction being different than the first direction and the second direction. The third direction may be offset from the first direction by an offset angle that is an acute angle. The apparatus may also include a screen; an imaging system configured to capture an image of the screen. The first light emitter and the third light emitter may both be configured to emit light toward the screen.