1. A method for rendering a 3D model of a 3D object as an image including image samples, wherein the 3D model is a distance field, and the distance field includes surface cells representing portions of a surface of the 3D object, comprising the steps of: determining, in an object-order phase for each surface cell, a set of image samples in the image; processing each surface cell, independent of other surface cells, wherein the processing of each surface cell further comprises: casting a ray, in an image order phase and from each image sample in the set of image samples, through the surface cell to determine a contribution of the surface cell to the image sample; and rendering the image.