Methods of reconstructing a 3D object model from portions of an object in a single 2D image using an existing 3D object model that is generic to a class to which the object in the 2D image belongs. In some embodiments, the methods determine a camera center from a computed estimated camera projection matrix. Landmark points on the object in the 2D image are back-projected to the existing 3D object model to warp the existing 3D object model according to the landmark points in the 2D image to create a derived 3D object model of the 2D object in the 2D image. Optional additional processing steps can include regularization, texturing, and infill of missing regions of the derived 3D object model. An example implementation of the disclosed methods is 3D craniofacial reconstruction from a single 2D image containing at least a portion of a face.