3D PRINTING WITH CUSTOM SURFACE REFLECTION

• US 20150079327A1
• Filed: 09/18/2013
• Published: 03/19/2015
• Est. Priority Date: 09/18/2013
• Status: Active Grant

• Current Assignee: Disney Enterprises Incorporated (The Walt Disney Company)
• Original Assignee: Disney Enterprises Incorporated (The Walt Disney Company)
• Inventors: MATUSIK, WOJCIECH, KAUTZ, JAN, ROULLIER, OLIVIER, BICKEL, BERND, ALEXA, MARC
• Granted Patent: US 9,266,287 B2
• Time in Patent Office: Days
• US Class Current: 428/64.1
• CPC Class Codes: B29C 64/393 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B29K 2995/0026 Transparent
• CPC Class Codes: B29K 2995/003 Reflective
• CPC Class Codes: B29L 2031/773 Dome-shaped igloos B29L2031/106, frameless domes B29L2025/00
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: Y10T 428/21 Circular sheet or circular blank
• CPC Class Codes: Y10T 428/24355 Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]

Abstract

A method for fabricating custom surface reflectance and spatially-varying bi-directional reflectance distribution functions (BDRFs or svBRDFs). The 3D printing method optimizes micro-geometry to produce a normal distribution function (NDF) that can be printed on surfaces with a 3D printer. Particularly, the method involves optimizing the micro-geometry for a wide range of analytic NDFs and simulating the effective reflectance of the resulting surface. Using the results of the simulation, the appearance of an input svBRDF can be reproduced. To this end, the micro-geometry is optimized in a data-driven fashion and distributed on the surface of the printed object. The methods were demonstrated to allow 3D printing svBRDF on planar samples with current 3D printing technology even with a limited set of printing materials, and the described methods have been shown to be naturally extendable to printing svBRDF on arbitrary shapes or 3D objects.

Claims

1. A 3D printed object, comprising:

a base layer; and

a micro-structure layer covering the base layer, wherein the micro-structure layer comprises a back surface adjacent the base layer and a front surface opposite the base layer, wherein the front surface comprises a plurality of reflectance elements, and wherein the reflectance elements are configured to define a set of reflectance properties.

2. The object of claim 1, wherein the base layer is formed of materials to be diffuse and wherein the micro-structure layer is formed of a substantially transparent material.

3. The object of claim 1, wherein the reflectance elements each comprise a body extending outward and wherein the body comprises an outer surface with a plurality of facets providing the set of reflectance properties.

4. The object of claim 3, wherein the facets are of substantially equal area.

5. The object of claim 3, wherein the facets have a geometry based on a normal distribution function (NDF) associated with the set of reflectance properties.

6. The object of claim 5, wherein the geometry defines a number, a size, and a shape of the facets.

7. The object of claim 6, wherein the geometry defines a height and an outer dimension of a base of the body.

8. The object of claim 7, wherein the base of the body is circular or oval in shape.

9. The object of claim 1, wherein the surface further comprises a second plurality of reflectance elements configured to define a second set of reflectance properties differing from the set of reflectance properties of the plurality of reflectance elements, whereby the 3D printed object has an outer surface with at least two reflectances.

10. A 3D printing method, comprising:

providing a diffuse base layer;

printing a layer of transparent material comprising a surface with a plurality of micro-structures, wherein the micro-structures are configured based on a 3D model defining a geometry corresponding to a numerical representation of a target reflectance; and

forming a 3D printed object by attaching the layer of transparent material to the diffuse base layer with the micro-structures facing away from the diffuse base layer to define reflectance for the 3D printed object.

11. The method of claim 10, wherein the providing, the printing, and the forming are performed by a single multi-material 3D printer.

12. The method of claim 10, further comprising measuring reflectances of printing materials available for the diffuse base layer and the layer of transparent material and, based on the measured reflectances, optimizing the geometry of the micro-structures to reproduce the numerical representation.

13. The method of claim 10, wherein the numerical representation comprises a normal distribution function (NDF).

14. The method of claim 13, wherein the geometry of each of the micro-structures is provided by performing a Voronoi optimization.

15. The method of claim 14, wherein each of the micro-structures comprises a base with one or more sidewalls extending outward from the base and wherein outer surfaces of the one or more sidewalls comprises a plurality of facets.

16. The method of claim 15, wherein the facets each have substantially equal areas.

17. The method of claim 15, wherein the base is circular or oval in shape, whereby the body is dome shaped.

18. A method for used in 3D printing an object with customizable reflectances, comprising:

for a set of printing materials for a 3D printer, determining a bidirectional reflectance distribution function (BRDF) for a base diffuse layer and for a specular outer layer;

with a set of normal distribution functions (NDFs), computing a corresponding geometry for a multi-faceted micro-structure;

measuring reflectances of the specular outer layer with a surface of the specular outer layer comprising a plurality of the multi-faceted micro-structures corresponding to each of the NDFs with the set of printing materials;

simulating a resulting BRDF of the base diffuse layer covered with the specular outer layer with the multi-faceted micro-structures;

with an input target reflectance, determining a geometry of the multi-faceted micro-structures and a density on the surface of the specular outer layer to synthesize one of the NDFs; and

operating a 3D printer to print a 3D object using the determined geometry and the set of printer materials.

19. The method of claim 18, wherein the determining the geometry comprises performing Voronoi optimization of to define facets of the micro-structures.

20. The method of claim 18, further comprising with an additional input target reflectance, determining an additional geometry of the multi-faceted micro-structures to synthesize another one of the NDFs and wherein the operating of the 3D printer comprises printing the 3D object using the determined geometry, whereby the printed 3D object has two or more reflectances.