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The DSpace digital repository system captures, stores, indexes, preserves, and distributes digital research material.Thu, 25 Jul 2024 10:36:12 GMT2024-07-25T10:36:12ZVariational geometric modeling with black box constraints and DAGs
http://hdl.handle.net/10985/11350
Variational geometric modeling with black box constraints and DAGs
GOUATY, Gilles; FANG, Lincong; MICHELUCCI, Dominique; DANIEL, Marc; RAFFIN, Romain; LANQUETIN, Sandrine; NEVEU, Marc; PERNOT, Jean-Philippe
CAD modelers enable designers to construct complex 3D shapes with high-level B-Rep operators. This avoids the burden of low level geometric manipulations. However a gap still exists between the shape that the designers have in mind and the way they have to decompose it into a sequence of modeling steps. To bridge this gap, Variational Modeling enables designers to specify constraints the shape must respect. The constraints are converted into an explicit system of mathematical equations (potentially with some inequalities) which the modeler numerically solves. However, most of available programs are 2D sketchers, basically because in higher dimension some constraints may have complex mathematical expressions. This paper introduces a new approach to sketch constrained 3D shapes. The main idea is to replace explicit systems of mathematical equations with (mainly) Computer Graphics routines considered as Black Box Constraints. The obvious difficulty is that the arguments of all routines must have known numerical values. The paper shows how to solve this issue, i.e., how to solve and optimize without equations. The feasibility and promises of this approach are illustrated with the developed DECO (Deformation by Constraints) prototype.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/10985/113502016-01-01T00:00:00ZGOUATY, GillesFANG, LincongMICHELUCCI, DominiqueDANIEL, MarcRAFFIN, RomainLANQUETIN, SandrineNEVEU, MarcPERNOT, Jean-PhilippeCAD modelers enable designers to construct complex 3D shapes with high-level B-Rep operators. This avoids the burden of low level geometric manipulations. However a gap still exists between the shape that the designers have in mind and the way they have to decompose it into a sequence of modeling steps. To bridge this gap, Variational Modeling enables designers to specify constraints the shape must respect. The constraints are converted into an explicit system of mathematical equations (potentially with some inequalities) which the modeler numerically solves. However, most of available programs are 2D sketchers, basically because in higher dimension some constraints may have complex mathematical expressions. This paper introduces a new approach to sketch constrained 3D shapes. The main idea is to replace explicit systems of mathematical equations with (mainly) Computer Graphics routines considered as Black Box Constraints. The obvious difficulty is that the arguments of all routines must have known numerical values. The paper shows how to solve this issue, i.e., how to solve and optimize without equations. The feasibility and promises of this approach are illustrated with the developed DECO (Deformation by Constraints) prototype.Towards a declarative modeling approach built on top of a CAD modeler
http://hdl.handle.net/10985/16981
Towards a declarative modeling approach built on top of a CAD modeler
DANIEL, Marc; DÉCRITEAU, Dorian; PERNOT, Jean-Philippe
Today’s CAD modelers are very efficient in processing 3D shapes of CAD models by means of B-Rep modeling operators such as pad, pocket, shaft, groove, hole, fillet and so on. At a lower description level, those modeling operators are based on Euler operators acting directly on the faces, edges and vertices of the B-Rep models. Using such a top-down approach, the designers do not have to work on low-level geometric entities, but rather manipulate so-called structural and detail features to shape directly the CAD models. However, there is still a gap between the shapes the designers have in mind and the way they have to decompose them in a succession of modeling steps. This paper proposes a new declarative modeling approach to design industrial shapes allowing the designers to interact with a CAD software at a more conceptual level. The designers enter a high-level description of the expected shapes that is then transformed through scripts into traditional CAD operators successively called to create the shapes. Compared to the traditional feature-based approaches, our declarative modeling approach is closer to the way designers think. It saves time while keeping all the advan- tages of existing efficient CAD modelers. This new approach aims at quickly creating drafts rather than final shapes. Those drafts can then be modified using classical CAD software in which our new approach is fully embedded. This approach is a first step towards a declarative CAD modeler.
Fri, 01 Jan 2016 00:00:00 GMThttp://hdl.handle.net/10985/169812016-01-01T00:00:00ZDANIEL, MarcDÉCRITEAU, DorianPERNOT, Jean-PhilippeToday’s CAD modelers are very efficient in processing 3D shapes of CAD models by means of B-Rep modeling operators such as pad, pocket, shaft, groove, hole, fillet and so on. At a lower description level, those modeling operators are based on Euler operators acting directly on the faces, edges and vertices of the B-Rep models. Using such a top-down approach, the designers do not have to work on low-level geometric entities, but rather manipulate so-called structural and detail features to shape directly the CAD models. However, there is still a gap between the shapes the designers have in mind and the way they have to decompose them in a succession of modeling steps. This paper proposes a new declarative modeling approach to design industrial shapes allowing the designers to interact with a CAD software at a more conceptual level. The designers enter a high-level description of the expected shapes that is then transformed through scripts into traditional CAD operators successively called to create the shapes. Compared to the traditional feature-based approaches, our declarative modeling approach is closer to the way designers think. It saves time while keeping all the advan- tages of existing efficient CAD modelers. This new approach aims at quickly creating drafts rather than final shapes. Those drafts can then be modified using classical CAD software in which our new approach is fully embedded. This approach is a first step towards a declarative CAD modeler.Towards a better integration of modelers and black box constraint solvers within the Product Design Process
http://hdl.handle.net/10985/17218
Towards a better integration of modelers and black box constraint solvers within the Product Design Process
MICHELUCCI, Dominique; DANIEL, Marc; FOUFOU, Sebti; PERNOT, Jean-Philippe
This paper presents a new way of interaction between modelers and solvers to support the Product Development Process (PDP). The proposed approach extends the functionalities and the power of the solvers by taking into account procedural constraints. A procedural constraint requires calling a procedure or a function of the modeler. This procedure performs a series of actions and geometric computations in a certain order. The modeler calls the solver for solving a main problem, the solver calls the modeler’s procedures, and similarly procedures of the modeler can call the solver for solving sub-problems. The features, specificities, advantages and drawbacks of the proposed approach are presented and discussed. Several examples are also provided to illustrate this approach.
Tue, 01 Jan 2019 00:00:00 GMThttp://hdl.handle.net/10985/172182019-01-01T00:00:00ZMICHELUCCI, DominiqueDANIEL, MarcFOUFOU, SebtiPERNOT, Jean-PhilippeThis paper presents a new way of interaction between modelers and solvers to support the Product Development Process (PDP). The proposed approach extends the functionalities and the power of the solvers by taking into account procedural constraints. A procedural constraint requires calling a procedure or a function of the modeler. This procedure performs a series of actions and geometric computations in a certain order. The modeler calls the solver for solving a main problem, the solver calls the modeler’s procedures, and similarly procedures of the modeler can call the solver for solving sub-problems. The features, specificities, advantages and drawbacks of the proposed approach are presented and discussed. Several examples are also provided to illustrate this approach.