1. A computer implemented method of initializing an orientation of a three-dimensional (3D) model of an object, comprising: accessing at least one three-dimensional (3D) model of the object and observed information of the object moving in space; and determining a primary orientation parameter for the 3D model from the observed information, including: detecting a plurality of contours for the object in the observed information and calculating a representative normal vector for at least some of the detected contours; accessing a tangent vector representing a 3D angle tangent to a point on a surface of the object and drawn to a point of observation; calculating a primary orientation parameter for the object using a cross-product of the representative normal vector and the tangent vector; and using the calculated primary orientation parameter to initialize the orientation of the 3D model of the object.