Method and system for generating a 3D digital model used for creating a hairpiece
A method for generating a 3D digital model used for creating a hairpiece are disclosed. The method comprises: obtaining a 3D model of a head, the 3D model containing a 3D surface mesh having one single boundary and color information associated with the 3D mesh; mapping the 3D model into a 2D image in such a manner that any continuously connected line on the 3D model is mapped into a continuously connected line in the 2D image, the 2D image containing a 2D mesh with color information applied thereto; displaying the 2D image; identifying a feature in the 2D image based on the color information; and mapping the identified feature back onto the 3D model. A system for generating a 3D digital model used for creating a hairpiece is also provided in another aspect of the present disclosure.
1. A method for generating a 3D digital model used for creating a hairpiece, comprising:
obtaining a 3D model of a head, the 3D model containing 3D geometry information and color information associated with the 3D geometry information;
mapping a surface of the 3D model into a 2D image in such a manner that any continuously connected line on the surface of the 3D model is mapped into a continuously connected line in the 2D image;
identifying a feature in the 2D image based on the color information; and
mapping the identified feature in the 2D image back onto the surface of the 3D model, wherein on the 3D model rendered with the color information, an outline of a target area to be covered with a hairpiece is indicated with a first 3D indicating line; the first 3D indicating line is mapped into a first 2D indicating line in the 2D image through said mapping the 3D model into a 2D image; and said identifying a feature in the 2D image comprises: identifying the first 2D indicating line in the 2D image.
2. The method of claim 1 , further comprising: processing the 3D model in such a manner that the surface of the 3D model has only one single boundary.
3. The method of claim 2 , wherein said processing the 3D model comprises: identifying one single largest piece of geometry in the initial 3D model; and removing the other pieces of geometry in the raw 3D model.
4. The method of claim 2 , wherein said processing the 3D model comprises: cutting the 3D model with a cutting plane, which is positioned so that a concerned portion of the 3D model is entirely on one side of the cutting plane, and discarding the other portion of the 3D model that is on the other side of the cutting plane.
5. The method of claim 2 , wherein the surface of the 3D model is presented in a 3D mesh, and
said mapping the surface of the 3D model into a 2D image comprising: mapping the single boundary of the 3D mesh along a 2D boundary of a predetermined shape of the 2D image.
6. The method of claim 1 , wherein the 2D image contains a 2D polygon mesh and color information applied to the 2D polygon mesh, and
said mapping the surface of the 3D model into a 2D image comprising: solving for 2D position of vertices of the 2D polygon mesh that are mapped from the interior vertices of the 3D mesh, by using an energy minimization technique.
7. The method of claim 6 , wherein the energy minimization technique is an angle preserving technique or an area preserving technique.
8. The method of claim 1 , wherein said identifying a feature in the 2D image is implemented with an algorithm automatically.
9. The method of claim 1 , wherein said identifying a feature in the 2D image comprises:
displaying the 2D image; and
detecting a tracing action of a user that traces the feature in the 2D image and recording a trajectory of the tracing action as the identified feature in the 2D image.
10. The method of claim 9 , wherein the trajectory of the tracing action is presented as an overlay on the 2D image.
11. The method of claim 9 , further comprising: ignoring the tracing action according to an instruction from the user.
12. The method of claim 9 , further comprising: ignoring a tracing action if the tracing action traces a feature indicating an outline of a target area and a trajectory of the tracing action does not form a closed loop.
13. The method of claim 1 , wherein on the 3D model rendered with the color information, a hair part line is indicated with a second 3D indicating line;
the second 3D indicating line is mapped into a second 2D indicating line in the 2D image through said mapping the 3D model into a 2D image; and
said identifying a feature in the 2D image further comprises: identifying the second 2D indicating line in the 2D image.
14. The method of claim 1 , further comprising: after mapping the identified feature back onto the 3D model, generating an indicator for indicating the identified feature on the 3D model.
15. One or more processor non-transitory readable storage devices having encoded thereon instructions for causing one or more processors to perform the method for generating a 3D digital model used for creating a hairpiece of claim 1 .
16. A system for generating a 3D digital model used for creating a hairpiece, comprising: one or more processors and one or more processor readable storage devices, wherein the one or more processor readable storage devices have encoded thereon instructions for causing the one or more processors to perform the method of claim 1 .
17. The system of claim 16 , further comprising a display for displaying the 2D image.
18. The system of claim 17 , wherein the display comprises a touch screen.
19. The system of claim 17 , wherein the display, the one or more processor readable storage devices and the one or more processors are integrated in a tablet, and
the system further comprises a 3D scanner attached to the tablet for scanning a head three-dimensionally by optical means.