1. A method of capturing gestural motion of a control object in a three-dimensional (3D) sensory space, the method including: determining observation information characterizing a surface of a control object from at least one image of a gestural motion of the control object in a three-dimensional (3D) sensory space by fitting a family of closed curves and positions of a plurality of two-dimensional (2D) cross-sectional portions of the control object to the image based at least on a location of at least one image capturing device; constructing a 3D solid model to represent the control object by fitting one or more 3D solid subcomponents to the characterized surface; and improving the 3D solid model's representation of the gestural motion by: determining an error indication between a point on the characterized surface of the control object and a corresponding point on at least one of the 3D solid subcomponents; and responsive to the error indication adjusting the 3D solid model.