Heterogeneous object modeling based on multi-color distance field

With the development of layered manufacturing or rapid prototyping, modeling heterogeneous object with varying material distribution has become more and more important. Different from homogeneous object modeling, the heterogeneous object modeling contains not only geometry and topology information but also material information. In this paper, a new method of modeling heterogeneous object is presented. In this method, firstly, the geometric model of an object is represented by the signed distance field; next, each grid is assigned with material property and material distance field which has the same resolution with geometric distance field are calculated according to material feature; the geometric and material distance field are then unified, named as multi-color distance field. The complex heterogeneous object can also be obtained via the boolean operations of multi-color distance field. For a heterogeneous object represented by the distance field, the most significant advantage is that its geometry model and material information can easily be sliced into a series of 2D layers, so it is convenient for the heterogeneous object to be fabricated using layered manufacturing machine. Several examples show the validity of our modeling method.