3D model enhancement

1. A method comprising:

receiving a fine mesh as input, the fine mesh representing a 3-Dimensional (3D) model and comprising a first plurality of fine-mesh polygons, a second plurality of fine-mesh polygons, and a third plurality of fine-mesh polygons;

grouping the first plurality of fine-mesh polygons, the second plurality of fine-mesh polygons, and the third plurality of fine-mesh polygons into a first near-planar region of a coarse mesh and a second near-planar region of the coarse mesh, the first near-planar region comprising a first coarse-mesh polygon corresponding to the first plurality of fine-mesh polygons, the second near-planar region comprising a second coarse-mesh polygon corresponding to the second plurality of fine-mesh polygons and a third coarse-mesh polygon corresponding to the third plurality of fine-mesh polygons;

applying a deformation to the coarse mesh, wherein applying the deformation the coarse mesh comprises:

increasing an angle between the first coarse-mesh polygon and the second coarse-mesh polygon based on the first coarse-mesh polygon being in the first near-planar region and the second coarse-mesh polygon being in the second near-planar region, and

decreasing an angle between the second coarse-mesh polygon and the third coarse-mesh polygon based on the second coarse-mesh polygon and the third coarse-mesh polygon being in the second near-planar region; and

transforming the deformation into a modification for the fine mesh; and

applying the modification to at least some of the first plurality of fine-mesh polygons, at least some of the second plurality of fine-mesh polygons, and at least some of the third plurality of fine-mesh polygons.

2. The method of claim 1 , wherein applying the deformation comprises:

accessing an energy function having an output based on positions of vertices of the coarse mesh, wherein a first term of the energy function (i) relates a normal of the first coarse-mesh polygon to a normal of the second coarse-mesh polygon and (ii) has a first weight causing an increase in the angle between the first coarse-mesh polygon and the second coarse-mesh polygon, wherein a second term of the energy function (i) relates the normal of the second coarse-mesh polygon to a normal of the third coarse-mesh polygon and (ii) has a second weight causing an decrease in the angle between the second coarse-mesh polygon and the third coarse-mesh polygon; and

minimizing the output of the energy function, wherein minimizing the output comprises modifying a subset of the positions of vertices.

3. The method of claim 2 , wherein the energy function also includes a term that maintains a threshold similarity of the coarse mesh relative to an original configuration of the coarse mesh when the energy function is minimized.

4. The method of claim 1 , wherein transforming the deformation into the modification for the fine mesh comprises:

generating a rotation matrix by comparing a normal of each coarse-mesh polygon prior to the deformation being applied and a normal of each coarse-mesh polygon subsequent to the deformation being applied, wherein the rotation matrix transforms the normal prior to the deformation being applied into the normal subsequent to the deformation being applied; and

applying rotations in the rotation matrix to corresponding fine-mesh polygons in the fine mesh.

5. The method of claim 1 , wherein applying the deformation comprises optimizing an energy function using a term weighted for a particular edge between coarse-mesh polygons adjacent to one another, wherein optimizing the energy function causes at least one of:

accentuating a first feature in the 3D model that corresponds to the first coarse-mesh polygon and the second coarse-mesh polygon by increasing the angle between the first coarse-mesh polygon and the second coarse-mesh polygon; or

smoothing a second feature in the 3D model that corresponds to the second coarse-mesh polygon and the third coarse-mesh polygon by decreasing the angle between the second coarse-mesh polygon and the third coarse-mesh polygon.

6. The method of claim 1 , wherein transforming the deformation into the modification and applying the modification comprises applying a rotation and controlling polygon edge length to avoid polygon collapse.

7. The method of claim 1 , wherein transforming the deformation into the modification and applying the modification comprises applying a rotation matrix to polygons in the fine mesh.

8. The method of claim 1 , wherein the first near-planar region, the second near-planar region, and the third near-planar region approximate planes of a naturally occurring object.

9. A system comprising:

a processor; and

a non-transitory computer-readable medium communicatively coupled to the processor, wherein the processor is configured for executing instructions stored in the non-transitory computer-readable medium to perform operations comprising:

receiving a fine mesh as input, the fine mesh representing a 3-Dimensional (3D) model and comprising a first plurality of fine-mesh polygons, a second plurality of fine-mesh polygons, and a third plurality of fine-mesh polygons,

grouping the first plurality of fine-mesh polygons, the second plurality of fine-mesh polygons, and the third plurality of fine-mesh polygons into a first near-planar region of a coarse mesh and a second near-planar region of the coarse mesh, the first near-planar region comprising a first coarse-mesh polygon corresponding to the first plurality of fine-mesh polygons, the second near-planar region comprising a second coarse-mesh polygon corresponding to the second plurality of fine-mesh polygons and a third coarse-mesh polygon corresponding to the third plurality of fine-mesh polygons,

applying a deformation to the coarse mesh, wherein applying the deformation the coarse mesh comprises:

increasing an angle between the first coarse-mesh polygon and the second coarse-mesh polygon based on the first coarse-mesh polygon being in the first near-planar region and the second coarse-mesh polygon being in the second near-planar region, and

decreasing an angle between the second coarse-mesh polygon and the third coarse-mesh polygon based on the second coarse-mesh polygon and the third coarse-mesh polygon being in the second near-planar region, and

transforming the deformation into a modification for the fine mesh, and

applying the modification to at least some of the first plurality of fine-mesh polygons, at least some of the second plurality of fine-mesh polygons, and at least some of the third plurality of fine-mesh polygons.

10. The system of claim 9 , wherein applying the deformation comprises:

accessing an energy function having an output based on positions of vertices of the coarse mesh, wherein a first term of the energy function (i) relates a normal of the first coarse-mesh polygon to a normal of the second coarse-mesh polygon and (ii) has a first weight causing an increase in the angle between the first coarse-mesh polygon and the second coarse-mesh polygon, wherein a second term of the energy function (i) relates the normal of the second coarse-mesh polygon to a normal of the third coarse-mesh polygon and (ii) has a second weight causing an decrease in the angle between the second coarse-mesh polygon and the third coarse-mesh polygon; and

minimizing the output of the energy function, wherein minimizing the output comprises modifying a subset of the positions of vertices.

11. The system of claim 9 , wherein the energy function also includes a term that maintains a threshold similarity of the coarse mesh relative to an original configuration of the coarse mesh when the energy function is minimized.

12. The system of claim 9 , wherein transforming the deformation into the modification for the fine mesh comprises:

generating a rotation matrix by comparing a normal of each coarse-mesh polygon prior to the deformation being applied and a normal of each coarse-mesh polygon subsequent to the deformation being applied, wherein the rotation matrix transforms the normal prior to the deformation being applied into the normal subsequent to the deformation being applied; and

applying rotations in the rotation matrix to corresponding fine-mesh polygons in the fine mesh.

13. The system of claim 9 , wherein applying the deformation comprises optimizing an energy function using a term weighted for a particular edge between coarse-mesh polygons adjacent to one another, wherein optimizing the energy function causes at least one of:

accentuating a first feature in the 3D model that corresponds to the first coarse-mesh polygon and the second coarse-mesh polygon by increasing the angle between the first coarse-mesh polygon and the second coarse-mesh polygon; or

smoothing a second feature in the 3D model that corresponds to the second coarse-mesh polygon and the third coarse-mesh polygon by decreasing the angle between the second coarse-mesh polygon and the third coarse-mesh polygon.

14. The system of claim 9 , wherein transforming the deformation into the modification and applying the modification comprises applying a rotation and controlling polygon edge length to avoid polygon collapse.

15. A non-transitory computer-readable medium having instructions stored thereon that are executable by a processing device, the instructions comprising:

instructions for receiving a fine mesh as input, the fine mesh representing a 3-Dimensional (3D) model and comprising a first plurality of fine-mesh polygons, a second plurality of fine-mesh polygons, and a third plurality of fine-mesh polygons;

instructions for grouping the first plurality of fine-mesh polygons, the second plurality of fine-mesh polygons, and the third plurality of fine-mesh polygons into a first near-planar region of a coarse mesh and a second near-planar region of the coarse mesh, the first near-planar region comprising a first coarse-mesh polygon corresponding to the first plurality of fine-mesh polygons, the second near-planar region comprising a second coarse-mesh polygon corresponding to the second plurality of fine-mesh polygons and a third coarse-mesh polygon corresponding to the third plurality of fine-mesh polygons;

instructions for applying a deformation to the coarse mesh, wherein applying the deformation the coarse mesh comprises:

increasing an angle between the first coarse-mesh polygon and the second coarse-mesh polygon based on the first coarse-mesh polygon being in the first near-planar region and the second coarse-mesh polygon being in the second near-planar region, and

decreasing an angle between the second coarse-mesh polygon and the third coarse-mesh polygon based on the second coarse-mesh polygon and the third coarse-mesh polygon being in the second near-planar region, and

transforming the deformation into a modification for the fine mesh; and

instructions for applying the modification to at least some of the first plurality of fine-mesh polygons, at least some of the second plurality of fine-mesh polygons, and at least some of the third plurality of fine-mesh polygons.

16. The non-transitory computer-readable medium of claim 15 , wherein applying the deformation comprises:

accessing an energy function having an output based on positions of vertices of the coarse mesh, wherein a first term of the energy function (i) relates a normal of the first coarse-mesh polygon to a normal of the second coarse-mesh polygon and (ii) has a first weight causing an increase in the angle between the first coarse-mesh polygon and the second coarse-mesh polygon, wherein a second term of the energy function (i) relates the normal of the second coarse-mesh polygon to a normal of the third coarse-mesh polygon and (ii) has a second weight causing an decrease in the angle between the second coarse-mesh polygon and the third coarse-mesh polygon; and

minimizing the output of the energy function, wherein minimizing the output comprises modifying a subset of the positions of vertices.

17. The non-transitory computer-readable medium of claim 16 , wherein the energy function also includes a term that maintains a threshold similarity of the coarse mesh relative to an original configuration of the coarse mesh when the energy function is minimized.

18. The non-transitory computer-readable medium of claim 15 , wherein transforming the deformation into the modification for the fine mesh comprises:

generating a rotation matrix by comparing a normal of each coarse-mesh polygon prior to the deformation being applied and a normal of each coarse-mesh polygon subsequent to the deformation being applied, wherein the rotation matrix transforms the normal prior to the deformation being applied into the normal subsequent to the deformation being applied; and

applying rotations in the rotation matrix to corresponding fine-mesh polygons in the fine mesh.

19. The non-transitory computer-readable medium of claim 15 , wherein applying the deformation comprises optimizing an energy function using a term weighted for a particular edge between coarse-mesh polygons adjacent to one another, wherein optimizing the energy function causes at least one of:

accentuating a first feature in the 3D model that corresponds to the first coarse-mesh polygon and the second coarse-mesh polygon by increasing the angle between the first coarse-mesh polygon and the second coarse-mesh polygon; or

smoothing a second feature in the 3D model that corresponds to the second coarse-mesh polygon and the third coarse-mesh polygon by decreasing the angle between the second coarse-mesh polygon and the third coarse-mesh polygon.

20. The non-transitory computer-readable medium of claim 15 , wherein transforming the deformation into the modification and applying the modification comprises applying a rotation and controlling polygon edge length to avoid polygon collapse.