Three-dimensional threshold matrix for three-dimensional halftoning

A computer-implemented method for generating a three-dimensional halftone threshold matrix for use in production of a three-dimensional object, comprising:

• loading data comprising values for a halftone threshold matrix in two dimensions;
• generating a set of sub-matrices in the two-dimensions based on values from the halftone threshold matrix, including:
• processing values for the set of sub-matrices to introduce a lateral shift between subsequent sub-matrices in the set, the lateral shift being in at least one of said two dimensions;
• and
• generating a three-dimensional halftone threshold matrix for use in production of a three-dimensional object by combining the processed values for the set of sub-matrices in a third dimension,
• wherein the processed values for each sub-matrix represent halftone threshold values for application to a section of a digital representation corresponding to a layer of the three-dimensional object.

An electronic data structure for use in three-dimensional halftoning comprising:

• data values defined in association with a plurality of co-ordinates in three-dimensional space, the co-ordinates representing a grid resolution in x, y and z dimensions,
• wherein the data values comprise threshold values for a three-dimensional halftone operation and are representative of a plurality of z-dimension planes arranged parallel to the x and y dimensions,
• wherein each set of data values associated with a z-dimension plane comprise at least a subset of data values from a predefined two-dimensional halftone threshold matrix, and
• wherein data values associated with at least one z-dimension plane comprise data values from the predefined two-dimensional halftone threshold matrix that are shifted in one or more of the x and y dimensions.