Methods of constructing a printable 3D model, and related devices and computer program products

1. A method of constructing a printable three-dimensional (3D) model, the method comprising:

constructing a ray-cast mesh representation of an object by using ray-casting on a preliminary digital 3D model of the object; and

converting the preliminary digital 3D model of the object into the printable 3D model of the object by adding, to the preliminary digital 3D model of the object, an interior surface that is based on the ray-cast mesh representation,

wherein the using ray-casting on the preliminary digital 3D model comprises:

constructing a first portion of the ray-cast mesh representation by using cylindrical coordinates to model a first portion of the object; and

constructing a second portion of the ray-cast mesh representation by using spherical coordinates to model a second portion of the object.

2. The method of claim 1 ,

wherein the preliminary digital 3D model comprises a first 3D mesh representation of the object that is printable as a solid physical 3D model,

wherein the printable 3D model comprises a second 3D mesh representation of the object that is printable as a hollow physical 3D model, and

wherein the converting comprises using the ray-cast mesh representation to convert the first 3D mesh representation into the second 3D mesh representation.

3. The method of claim 1 ,

wherein the preliminary digital 3D model comprises a plurality of polygons of an exterior surface of the preliminary digital 3D model that model features of the object, and

wherein the using ray-casting on the preliminary digital 3D model comprises locating ones of the plurality of polygons of the exterior surface.

4. The method of claim 3 , wherein the locating the ones of the plurality of polygons of the exterior surface comprises:

using cylindrical coordinates to locate a first plurality of triangles of a first portion of the exterior surface; and

using spherical coordinates to locate a second plurality of triangles of a second portion of the exterior surface.

5. The method of claim 3 , wherein the locating the ones of the plurality of polygons of the exterior surface comprises:

locating a nearest first plurality of triangles that are in a first plane to which an axis that extends through the preliminary digital 3D model is perpendicular; and

locating a nearest second plurality of triangles that are in a second plane to which the axis is perpendicular.

6. The method of claim 3 , wherein the locating the ones of the plurality of polygons of the exterior surface comprises:

performing a discrete number of searches for a plurality of triangles in a first portion of the exterior surface; and

performing the discrete number of searches for the plurality of triangles in a second portion of the exterior surface.

7. The method of claim 6 ,

wherein the performing the discrete number of searches for the plurality of triangles in the first portion of the exterior surface comprises searching in a discrete number of directions to construct the first portion of the ray-cast mesh representation by using cylindrical coordinates, and

wherein the performing the discrete number of searches for the plurality of triangles in the second portion of the exterior surface comprises searching in the discrete number of directions to construct the second portion of the ray-cast mesh representation by using spherical coordinates.

8. The method of claim 1 , wherein the converting comprises shaping the interior surface to construct the printable 3D model as a hollow digital shell comprising an opening that exposes the interior surface.

9. The method of claim 1 , wherein the converting comprises:

forming a first portion of the interior surface based on a cylinder; and

forming a second portion of the interior surface based on a sphere or hemisphere.

10. The method of claim 1 , further comprising providing the printable 3D model, from a portable electronic device that performs the ray-casting on the preliminary digital 3D model, to a 3D printer.

11. The method of claim 1 , wherein the converting comprises forming the interior surface at a predetermined distance from an exterior surface of the preliminary digital 3D model.

12. The method of claim 1 , further comprising:

receiving, in a storage medium, image data for the object from an image capture device; and

constructing the preliminary digital 3D model based on the image data.

13. The method of claim 1 , wherein an exterior surface of the preliminary digital 3D model comprises a higher level of topological detail of a surface of the object than the interior surface.

14. An electronic device comprising:

a processor; and

a storage medium coupled to the processor and comprising computer readable program code therein that when executed by the processor causes the processor to perform the method of claim 1 .

15. A computer program product comprising:

a non-transitory computer readable storage medium comprising computer readable program code therein that when executed by a processor causes the processor to perform the method of claim 1 .

16. A computer program product comprising:

a non-transitory computer readable storage medium comprising computer readable program code therein that when executed by a processor causes the processor to perform operations comprising:

constructing a ray-cast mesh representation of an object by using ray-casting on a preliminary digital 3D model of the object;

converting the preliminary digital 3D model of the object into a printable 3D model of the object by adding, to the preliminary digital 3D model of the object, an interior surface that is based on the ray-cast mesh representation; and

providing the printable 3D model to a 3D printer,

wherein the using ray-casting on the preliminary digital 3D model comprises:

constructing a first portion of the ray-cast mesh representation by using cylindrical coordinates to model a first portion of the object; and

constructing a second portion of the ray-cast mesh representation by using spherical coordinates to model a second portion of the object.

17. The computer program product of claim 16 ,

wherein the preliminary digital 3D model comprises a plurality of triangles of an exterior surface of the preliminary digital 3D model that model features of the object, and

wherein the computer readable program code comprises computer readable program code configured to perform the ray-casting on the preliminary digital 3D model by:

using cylindrical coordinates to locate first ones of the plurality of triangles of a first portion of the exterior surface; and

using spherical coordinates to locate second ones of the plurality of triangles of a second portion of the exterior surface.

18. An electronic device comprising:

a processor; and

a storage medium coupled to the processor and comprising computer readable program code that when executed by the processor causes the processor to perform operations comprising:

constructing a ray-cast mesh representation of an object by using ray-casting on a preliminary digital 3D model of the object; and

converting the preliminary digital 3D model of the object into a printable 3D model of the object by adding, to the preliminary digital 3D model of the object, an interior surface that is based on the ray-cast mesh representation,

wherein the electronic device is a portable electronic device comprising the storage medium, the processor, and an image capture device that is configured to capture image data of the object,

wherein the portable electronic device comprises a smartphone, a tablet computer, a laptop computer, or a portable camera,

wherein the preliminary digital 3D model comprises a plurality of triangles of an exterior surface of the preliminary digital 3D model that model features of the object based on the image data, and

wherein the processor is configured to perform the ray-casting on the preliminary digital 3D model by:

using cylindrical coordinates to locate first ones of the plurality of triangles of a first portion of the exterior surface; and

using spherical coordinates to locate second ones of the plurality of triangles of a second portion of the exterior surface.

19. The electronic device of claim 18 ,

wherein the processor is configured to perform the converting by shaping the interior surface to construct the printable 3D model as a hollow digital shell comprising an opening that exposes the interior surface, and

wherein the processor is further configured to provide the hollow digital shell from the portable electronic device to a 3D printer.