1. A three-dimensional (3D) pointing sensing apparatus, comprising: an image generation unit to photograph a first light source and a second light source in a light emitting unit, and to generate an image including an image of the first light source and an image of a second light source; and an orientation calculation unit to calculate an orientation of the light emitting unit, using a size difference between the image of the first light source and the image of the second light source in the image using at least one processing device.