1. A method of determining spatial coordinates in three dimensional space, comprising: obtaining initial spatial coordinate values for an object in three dimensions using a signal received from one or more markers associated with the object by an optical sensor system; separately measuring a distance to the object using a separate non-contact distance measurement device, wherein the separately measuring a distance to the object is performed separately from the obtaining initial spatial coordinate value for the object in the three dimensions; and combining the initial spatial coordinate values for the object in the three dimensions with the separately measured distance to obtain spatial coordinate values for the three dimensions.