According to aspects, provided is a method for displaying a three-dimensional geometry of a part to be 3D printed, comprising receiving the geometry of a part sliced into shells or layers, displaying the shells or layers, displaying, for a shell or layer, a representation of a distribution of a isotropic fill material, displaying, for an anisotropic fill subset of the set of shells or layers, a representation of a distribution of an anisotropic fill material having an anisotropic characteristic oriented relative to a trajectory of an anisotropic fill tool path, receiving a selection, from among the displayed shells or layers, of an editing subset, the editing subset including part of the anisotropic fill subset, and regenerating, for a shell or layer of the editing subset, one of a second representation of a distribution of isotropic fill material and a second representation of a distribution of anisotropic fill material.