Ensuring additive manufacturability of object model using meso-skeleton analysis
A three-dimensional object model is divided into a plurality of slices that are targeted for an additive manufacturing process having a minimum printable feature size. For each of the slices, a thinning algorithm is applied to one or more contours of the slice to form a meso-skeleton, where topological features of the thinned slice that are smaller than the minimum printable feature size are reduced to skeletal paths. A corrected slice is formed using the meso-skeleton by sweeping the meso-skeleton with the minimum printable feature size. The corrected slices are assembled into a corrected object model and the corrected object model is used in the additive manufacturing process.
1. A method comprising:
dividing a three-dimensional object model into a plurality of slices, the slices being targeted for an additive manufacturing process using an additive manufacturing machine that has a minimum printable feature size;
for each of the slices:
applying a thinning algorithm to one or more contours of the slice to form a meso-skeleton, wherein topological features of the thinned slice that are smaller than the minimum printable feature size are reduced to skeletal paths; and
forming a corrected slice using the meso-skeleton by sweeping the meso-skeleton with the minimum printable feature size, the thinning algorithm configured such that the slice is not thinned beyond an erosion of the contours by the minimum printable feature size;
assembling the corrected slices into a corrected object model; and
controlling the additive manufacturing machine using the corrected object model in the additive manufacturing process.
2. The method of claim 1 , wherein the thinning algorithm comprises a two sub-iteration thinning algorithm.
3. The method of claim 1 , further comprising, for each slice:
determining that at least one of the skeletal path comprises a spur; and
remove one or more pixels from an end of the spur such that a manufactured representation of the spur has a length corresponding to that of the three-dimensional object model.
4. The method of claim 1 , wherein, for each slice, forming the corrected slice comprises dilating the meso-skeleton with the minimum printable feature size.
5. The method of claim 1 , wherein, for each slice, the thinning algorithm is repeated until a union of the meso-skeleton with the erosion of the contours does not change between subsequent repetitions.
6. The method of claim 1 , wherein the corrected model is created at a design stage, the corrected model being further processed via a slicer and toolpath generator of the additive manufacturing process.
7. A method comprising:
for each angle of a plurality of build-direction angles of an additive manufacturing process having a minimum printable feature size, performing a computation comprising:
dividing a three-dimensional object model into a plurality of slices, the three-dimensional object model being targeted for the additive manufacturing process;
for each of the slices, forming a meso-skeleton via a thinning algorithm such that topological features of the thinned slice that are smaller than the minimum printable feature size are reduced to skeletal paths, a corrected slice being formed by sweeping the meso-skeleton with the minimum printable feature size;
assembling the corrected slices into a corrected object model; and
determining a difference between the corrected object model to the three-dimensional object for the angle;
determining a minimum difference of the differences obtained for each of the build-direction angles; and
using a selected angle corresponding to the minimum difference to build the three-dimensional object model in the additive manufacturing process.
8. The method of claim 7 , wherein, for each angle, a next angle is selected based on previously evaluated angles inside an optimization loop.
9. The method of claim 7 , wherein the computation is performed over a plurality of angle pairs measured relative to first and second orthogonal build axes, a selected angle pair corresponding to the minimum difference being used to build the three-dimensional object model in the additive manufacturing process.
10. The method of claim 7 , wherein the difference between the corrected object model to the three-dimensional object for the angle is weighted to favor one of material addition or material deletion in the corrected object model.
11. The method of claim 7 , wherein the thinning algorithm comprises a two sub-iteration thinning algorithm.
12. The method of claim 7 , wherein, for each slice, forming the corrected slice comprises dilating the meso-skeleton with the minimum printable feature size.
13. The method of claim 7 , wherein, for each slice, the thinning algorithm is repeated until a union of the meso-skeleton with an erosion of the contours does not change between subsequent repetitions.
14. The method of claim 7 , wherein the corrected model is created at a design stage, the corrected model being further processed via a slicer and toolpath generator of the additive manufacturing process.
15. The method of claim 7 , wherein determining the selected angle corresponding to the minimum difference comprises using a simulated annealing algorithm.
16. A system comprising
an additive manufacturing machine having a minimum printable feature size;
an apparatus comprising a processor coupled to memory, the processor configured to:
divide a three-dimensional object model into a plurality of slices, the slices being targeted for the additive manufacturing machine;
for each of the slices:
apply a thinning algorithm to one or more contours of the slice to form a meso-skeleton, wherein topological features of the thinned slice that are smaller than the minimum printable feature size are reduced to skeletal paths; and
form a corrected slice using the meso-skeleton by sweeping the meso-skeleton with the minimum printable feature size, the thinning algorithm configured such that the corrected slice is not thinned beyond an erosion of the contours by the minimum printable feature size;
assemble the corrected slices into a corrected object models; and
send the corrected object model to control the additive manufacturing machine using the corrected object model.
17. The system of claim 16 , wherein the thinning algorithm comprises a two sub-iteration thinning algorithm.
18. The system of claim 16 , further comprising, for each slice:
determining that at least one of the skeletal path comprises a spur; and
remove one or more pixels from an end of the spur such that a manufactured representation of the spur has a length corresponding to that in the three-dimensional object model.
19. The system of claim 16 , wherein, for each slice, forming the corrected slice comprises dilating the meso-skeleton with the minimum printable feature size.
20. The system of claim 16 , wherein, for each slice, the thinning algorithm is repeated until a union of the meso-skeleton with the erosion of the contours does not change between subsequent repetitions.
21. The system of claim 16 , wherein the corrected model is created at a design stage, the corrected model being further processed via a slicer and toolpath generator associated with the additive manufacturing machine.