1. A method for estimating a non-geometric physical parameter of an unrestrained livestock animal, comprising: projecting one or more predetermined light patterns onto at least a portion of the unrestrained livestock animal with a single calibrated device comprising a light projector and a light detector, wherein the unrestrained livestock animal is able to move relative to the single calibrated device within a commercial livestock environment; detecting one or more light patterns resulting from an interaction of one or more of the projected light patterns and at least a portion of the unrestrained livestock animal using the single device; processing, by data processing apparatus, the one or more detected light patterns to provide a three dimensional representation of at least a portion of the unrestrained livestock animal based on light patterns detected only by the single device; and using, by the data processing apparatus, the three dimensional representation of at least a portion of the unrestrained livestock animal to estimate the non-geometric physical parameter of the unrestrained livestock animal.