Abstract: A framework on heterogeneous material part (HMP) modeling is proposed based on voxel model. The description in the paper focuses on the multiple material objects and the functionally gradient models. By digital distance transform, a distance field is calculated from the object voxels to the features selected. A heterogeneous part can be modeled by mapping the object point into material space from geometry space by the criterion of the minimal distance. Finally, three examples of heterogeneous part modeling are presented.