Multi-material 3D object print method and print control apparatus

1. A multi-material 3D object printing method, comprising steps:

a. randomly generating at least one group of area print data based on each group of area information of a target object, correspondingly generating layer print data according to multiple groups of area information of each layer of the target object, and forming the multiple groups of layer print data into 3D object print data, wherein a randomness test is separately performed on the at least one group of area print data, and Y groups of area print data thereof that fail the randomness test are discarded, and Y groups of area print data are randomly generated, wherein Y≥0, wherein:

each group of area information comprises at least a quantity N of pixels, M types of materials, and a proportion of each material, comprised in a corresponding area of the area information, wherein the M types of materials are associated with the area print data, and the M types of materials comprise a first material, a second material, . . . , an (M−2) th material, an (M−1) th material, and an M th material, wherein associating an (M−1) th group of area print data in the M−1 groups of area print data with the (M−1) th material and the M th material including:

a1. generating new complementary area print data from the (M−1) th group of area print data; and

a2. associating the (M−1) th group of area print data and the complementary area print data with the (M−1) th material and the M th material, and

the area print data is generated by randomly generating M−1 groups of area print data according to each group of area information when each group of area information comprises M types of materials, wherein the M−1 groups of area print data comprise a first group of area print data, a second group of area print data, . . . , and an Xth group of area print data, wherein the area print data is binary data and 1≤X≤M−1, wherein M≥2, and correspondingly, the number of bits in the Xth group of area print data is N×(RX+ . . . +RM), RX is a proportion of an Xth material, RM is a proportion of an M th material, and the number of 0s or the number of is in the Xth group of area print data is N×RX;

b. performing layer-by-layer printing based on the 3D object print data; and

c. stacking layer-by-layer printing products from the step b to form a 3D object.

2. The printing method according to claim 1 , wherein after each group of area print data is generated, one randomness test is performed.

3. The printing method according to claim 2 , wherein the randomness test is performed by using a runs test method.

4. The printing method according to claim 1 , wherein the complementary area print data is generated by:

i1. generating reference data whose number of bits is the same as that of the (M−1) th group of area print data, and performing binary assignment on the reference data to form reference data whose values are all 1; and

i2. calculating a difference between the reference data and the (M−1) th group of area print data, to obtain the complementary area print data.

5. The printing method according to claim 4 , wherein the first group of area print data, the second group of area print data, . . . , and an (M−2) th group of area print data in the M−1 groups of area print data are associated with the first material, the second material, . . . , and the (M−2) th material, and the method further comprises:

a3. correcting at least one group of to-be-corrected area print data in the first group of area print data, the second group of area print data, . . . , and the (M−2) th group of area print data, to correspondingly obtain at least one group of corrected area print data; and

a4. correspondingly replacing the to-be-corrected area print data with the corrected area print data obtained after the correction.

6. The printing method according to claim 5 , wherein the corrected area print data is generated by:

i3. generating corrected data whose number of bits is the same as that of the to-be-corrected area print data, and performing binary assignment on the corrected data to form corrected data whose values are all 1; and

i4. calculating a difference between the corrected data and the to-be-corrected area print data, to obtain the corrected area print data.

7. The printing method according to claim 1 , wherein a corresponding area of each group of area information is divided into L rows and I columns, and N=L×I.

8. The printing method according to claim 7 , wherein the area information is obtained by:

a1. obtaining model data of the target object;

a2. obtaining material composition of different portions of the model data and proportions of materials; and

a3. performing layering processing on the target object, to obtain a quantity of pixels in a corresponding area of each layer, a material type, and a proportion of each material.

9. The printing method according to claim 8 , wherein the area print data is randomly generated by using a random number generator.

10. The printing method according to claim 9 , wherein the proportions of the materials are mass percentages.

11. The printing method according to claim 1 , wherein in the step c, each of the layer-by-layer printing products is cured and then stacked.

12. The printing method according to claim 11 , wherein in the step c, each of the layer-by-layer printing products is first leveled and cured, before being stacked.

13. A print control apparatus, comprising a data processor, a process controller, and a printhead, wherein

the data processor is configured to: obtain area information and randomly generate area print data according to the area information, and perform a randomness test and processing on the generated area print data, to generate 3D object print data, wherein a randomness test is separately performed on the at least one group of area print data, and Y groups of area print data thereof that fail the randomness test are discarded, and Y groups of area print data are randomly generated, wherein Y≥0, wherein:

each group of area information comprises at least a quantity N of pixels, M types of materials, and a proportion of each material, comprised in a corresponding area of the area information, wherein the M types of materials are associated with the area print data, and the M types of materials comprise a first material, a second material, . . . , an (M−2) th material, an (M−1) th material, and an M th material, wherein associating an (M−1) th group of area print data in the M−1 groups of area print data with the (M−1) th material and the M th material including:

a1. generating new complementary area print data from the (M−1) th group of area print data; and

a2. associating the (M−1) th group of area print data and the complementary area print data with the (M−1) th material and the M th material, and

the area print data is generated by randomly generating M−1 groups of area print data according to each group of area information when each group of area information comprises M types of materials, wherein the M−1 groups of area print data comprise a first group of area print data, a second group of area print data, . . . , and an Xth group of area print data, wherein the area print data is binary data and 1≤X≤M−1, wherein M and correspondingly, the number of bits in the Xth group of area print data is N×(RX+ . . . +RM), RX is a proportion of an Xth material, RM is a proportion of an M th material, and the number of 0s or the number of is in the Xth group of area print data is N×RX; and

the process controller controls the printhead to perform layer-by-layer printing based on the 3D object print data generated by the data processor, and stacks layer-by-layer printing products.

14. The print control apparatus according to claim 13 , further comprising a leveling apparatus, configured to level each of the layer-by-layer printing products.

15. The print control apparatus according to claim 14 , further comprising a curing apparatus, configured to cure each of the layer-by-layer printing products.

16. The printing method according to claim 1 , wherein the randomness test is separately performed on the at least one group of area print data by manually adjusting a significance level parameter for each corresponding group of area print data of the at least one group of area print data.