Method for computationally designing at least one rigid re-usable two-pieced mold (1, 1a, 1b) for the reproduction of a complex object or a resemblance thereof, wherein a complex object is an object for which no parting direction exists that allows non-destructive casting of said object with a single rigid two-pieced mold (1, 1a, 1b) in a single-stepped extraction process, wherein each two-pieced mold (1, 1a, 1b) is designed to enclose at least one cavity that is fillable with filling material to form the complex object, a resemblance of the complex object, or a part of the complex object, namely a sub-object (2a, 2b), to be reproduced within the mold (1, 1a, 1b), wherein each mold (1, 1a, 1b) consists of rigid material, comprising the following steps: a) taking as an initial input a digital surface description of the object to be reproduced, b) manipulation of the digital surface description of step a) in order to obtain a feasible digital representation (Df) and consequently to calculate at least one feasible re-usable two-pieced mold, wherein a feasible digital representation (Df) is a representation that allows for each two-pieced mold (1, 1a, 1b) a single-stepped non-destructive extraction process, b1) wherein the manipulation of the digital surface description is performed by applying at least one of the following amendments to the digital surface description: {object deformation, split of the complex object into a number of sub-objects (2a, 2b) and as such increasing the number of molds (1a, 1b), extending the complex object by adding at least one inset}, and b2) wherein the extent of manipulation according to step b1) is determined based on - an optimization algorithm, and/or - user-input preference data, and b3) wherein the optimization algorithm is applied to obtain at least one feasible two-pieced mold (1f, 1fa, 1fb) by way of calculating an optimized orientation and position of the object or sub-object (2a, 2b) within at least one feasible two-pieced mold (1, 1fa, 1fb) and consequently to calculate the shape of each piece of each two-pieced mold and its parting line, wherein the parting line is defined as at least one closed curve in 3D space that is shaped when the two pieces (U, L) of the mold (1f, 1fa, 1fb) and the cavity or the object within the mold meet one another, c) providing the at least one feasible two-pieced mold ((1f, 1fa, 1fb) of step b) as an output. a) taking as an initial input a digital surface description of the object to be reproduced, b) manipulation of the digital surface description of step a) in order to obtain a feasible digital representation (Df) and consequently to calculate at least one feasible re-usable two-pieced mold, wherein a feasible digital representation (Df) is a representation that allows for each two-pieced mold (1, 1a, 1b) a single-stepped non-destructive extraction process, b1) wherein the manipulation of the digital surface description is performed by applying at least one of the following amendments to the digital surface description: {object deformation, split of the complex object into a number of sub-objects (2a, 2b) and as such increasing the number of molds (1a, 1b), extending the complex object by adding at least one inset}, and b2) wherein the extent of manipulation according to step b1) is determined based on - an optimization algorithm, and/or - user-input preference data, and b3) wherein the optimization algorithm is applied to obtain at least one feasible two-pieced mold (1f, 1fa, 1fb) by way of calculating an optimized orientation and position of the object or sub-object (2a, 2b) within at least one feasible two-pieced mold (1, 1fa, 1fb) and consequently to calculate the shape of each piece of each two-pieced mold and its parting line, wherein the parting line is defined as at least one closed curve in 3D space that is shaped when the two pieces (U, L) of the mold (1f, 1fa, 1fb) and the cavity or the object within the mold meet one another, b1) wherein the manipulation of the digital surface description is performed by applying at least one of the following amendments to the digital surface description: {object deformation, split of the complex object into a number of sub-objects (2a, 2b) and as such increasing the number of molds (1a, 1b), extending the complex object by adding at least one inset}, and b2) wherein the extent of manipulation according to step b1) is determined based on - an optimization algorithm, and/or - user-input preference data, and - an optimization algorithm, and/or - user-input preference data, and b3) wherein the optimization algorithm is applied to obtain at least one feasible two-pieced mold (1f, 1fa, 1fb) by way of calculating an optimized orientation and position of the object or sub-object (2a, 2b) within at least one feasible two-pieced mold (1, 1fa, 1fb) and consequently to calculate the shape of each piece of each two-pieced mold and its parting line, wherein the parting line is defined as at least one closed curve in 3D space that is shaped when the two pieces (U, L) of the mold (1f, 1fa, 1fb) and the cavity or the object within the mold meet one another, c) providing the at least one feasible two-pieced mold ((1f, 1fa, 1fb) of step b) as an output.