Methoid and apparatus for generating a 3d model of an object

Abstract

A method for generating a 3D model for fabricating a multi-material object using additive manufacturing. The method comprises providing a first volumetric model of an object in a deformed configuration, generating a second volumetric model from the first volumetric model and assigning materials to the second volumetric model by: a) defining a cluster of elementary volumetric elements of the second volumetric model, b) selecting a cluster object material in the database of object materials by minimizing a cost function determined by computing a deformed configuration of the second volumetric model under a set of predefined loads and constraints, c) partitioning the elementary volumetric elements of the cluster in two sub-clusters based on the deformed configuration, d) repeating step b) for each sub-clusters. The method further comprises generating a 3D model for fabricating an object from the second volumetric model and the assigned materials.

1 .- 15 . (canceled) 
     
     
         16 . A method for generating a three-dimensional model for fabricating a multi-material anatomical model using additive manufacturing, the method comprising:
 providing a volumetric model of an anatomic object in a first configuration and in a second configuration, the volumetric model including a plurality of three-dimensional nodes which define a plurality of elementary volumetric elements partitioning a first space region modeled by the volumetric model;   determining mechanical properties of the three-dimensional model based on the first configuration and the second configuration, wherein the second configuration is a deform configuration under predefined loads and constraints;   assigning to each elementary volumetric element of the volumetric model a material selected in a database of plurality of materials by performing at least the following steps:   defining a cluster of elementary volumetric elements of the volumetric model, having identical mechanical properties;   assigning to each elementary volumetric element of the cluster identical intrinsic material properties associated to the material, wherein the intrinsic material properties define stress-strain relationship;   computing a cost function of the cluster associated to the material, the cost function being a function of the deformed configuration of the cluster and the deformed configuration of the volumetric model;   selecting a cluster object material in the database of plurality of materials by minimizing a cost function of the cluster; and generating a three-dimensional model for fabricating the anatomic object from the volumetric model and the materials assigned to each elementary volumetric element of the volumetric model.   
     
     
         17 . The method according to  claim 16 , wherein the selecting a cluster object material in the database of plurality of materials by minimizing a cost function of the cluster is performed for each material in the database of plurality of materials. 
     
     
         18 . The method according to  claim 16 , wherein the selecting a cluster object material in the database of plurality of materials by minimizing a cost function of the cluster further includes comparing the cost functions computed for each material in the database of plurality of materials. 
     
     
         19 . The method according to  claim 16 , wherein the cost function is a function of strain error between the cluster and the volumetric model. 
     
     
         20 . The method according to  claim 16 , wherein the cost function is a function of stress error between the cluster and the volumetric model. 
     
     
         21 . The method according to  claim 16 , wherein each of the plurality of elementary volumetric element of the volumetric model in first configuration is respectively associated with each volumetric element of the volumetric model in second configuration. 
     
     
         22 . The method according to  claim 16 , wherein the mechanical properties of the three-dimensional model is determined by comparing a location of at least one elementary volumetric element in the first configuration with a location of the at least one elementary volumetric element in the second configuration. 
     
     
         23 . The method according to  claim 16 , wherein the volumetric model is provided by;
 receiving a three-dimensional model of an object comprising at least one surface mesh representative of an interface of the object, in particular an interface of the object associated to discontinuity in physical properties of the object; and   generating the volumetric model from the at least one surface mesh by performing a volumetric model generation.   
     
     
         24 . The method according to  claim 16 , wherein the predefined loads and constraints comprise a load on the anatomical model. 
     
     
         25 . The method according to  claim 16 , wherein the predefined loads and constraints are selected from a list of volumetric forces, surface forces, punctual forces, thermal loads, electric charge, and magnetic charge. 
     
     
         26 . The method according to  claim 16 , wherein the mechanical properties of the three-dimensional model is uni-axial. 
     
     
         27 . The method according to  claim 16 , wherein the mechanical properties of the three-dimensional model is multi-axial. 
     
     
         28 . The method according to  claim 16 , wherein the mechanical properties are selected from a list of compressive strength, shear strength, coefficient friction, static friction, dynamic friction, surface tension, and elasticity. 
     
     
         29 . The method according to  claim 16 , further includes providing a third configuration of the volumetric model, wherein the third configuration is a deform configuration under a second predefined loads and constraints, which is different than the predefined loads and constraints of the second configuration. 
     
     
         30 . A system for generating a three-dimensional model for fabricating a multi-material anatomic object using additive manufacturing, the system comprising;
 a memory unit operative to store a volumetric model of an anatomic object in a first configuration and in a second configuration, wherein the second configuration is a deform configuration under predefined loads and constraints, the volumetric model being divided in a plurality of elementary volumetric elements,   a processing unit operative to assign to each elementary volumetric element of the volumetric model a material selected in a database of plurality of materials by:   defining a cluster of elementary volumetric elements of the volumetric model having identical mechanical properties;   assigning to each elementary volumetric element of the cluster identical intrinsic material properties associated to the material, wherein the intrinsic material properties define stress-strain relationship;   computing a cost function of the cluster associated to the material, the cost function being a function of the deformed configuration of the cluster and the deformed configuration of the volumetric model;   selecting a cluster object material in the database of plurality of materials by minimizing a cost function of the cluster; and   generating a three-dimensional model for fabricating the anatomic object from the volumetric model and the materials assigned to each elementary volumetric element of the volumetric model.   
     
     
         31 . The system of  claim 30  wherein the mechanical properties are selected from a list of compressive strength, shear strength, coefficient friction, static friction, dynamic friction, surface tension, and elasticity. 
     
     
         32 . The system of  claim 30  wherein the predefined loads and constraints comprise a load on the anatomical model. 
     
     
         33 . The system of  claim 30  wherein the selecting a cluster object material in the database of plurality of materials by minimizing a cost function of the cluster is performed for each material in the database of plurality of materials. 
     
     
         34 . The system of  claim 30  wherein the mechanical properties of the three-dimensional model is multi-axial. 
     
     
         35 . An anatomic object fabricated by three-dimensional model generated by method of  claim 16 , comprising;
 an organ copy being formed from plurality of materials;   an external surface of the organ copy, wherein the external surface of the organ copy is associated to discontinuity in physical properties of the organ copy; and   the materials selected from a database of plurality of materials are arranged so that the mechanical properties of the anatomic object under predefined loads and constraints matches the mechanical properties of a scanned physical original object under the predefined loads and constraints.