Classifications

• • G—PHYSICS
  • G06—COMPUTING OR CALCULATING; COUNTING
  • G06T—IMAGE DATA PROCESSING OR GENERATION, IN GENERAL
  • G06T17/00—Three-dimensional [3D] modelling for computer graphics
  • G06T17/30—Polynomial surface description

Definitions

• the present invention relates to the decoration of three-dimensional objects and more particularly methods and devices for modeling precut or clichés for three-dimensional objects with non-developable surfaces and for assisting the transfer of two-dimensional patterns on these objects.
• the decoration of planes is generally intended to carry the commercial image of the airlines and often includes the painting of names, signs and logos that must be perfectly realized.
• the adaptation of the airline model to the particular shapes of each aircraft is usually based on experience and empirical analysis. The validation of this adaptation is often linked to the realization of models.
• European Patent EP 0 593 340 discloses a method and a device for aiding the decoration of a three-dimensional object. The process consists of representing a three-dimensional model of the object decorated by a decoration path. It then consists in locating on the object, starting from the 3D model, at least some characteristic points of said path for positioning, for example, adhesive tapes for delimiting the decoration or stencils, or precut decorative elements, etc.
• This invention applies in particular to the decoration of an aircraft by logos, letters or distinctive signs on the outer surface of this aircraft.
• the invention solves at least one of the problems discussed above.
• the method further comprises a step of measuring at least one error between at least one of said developable surfaces of said three-dimensional object and said model of said three-dimensional object and in that said steps of decomposition of said at least one a portion of said three-dimensional object in a plurality of surfaces and approximation of said surfaces of said modeling of said three-dimensional object by said developable surfaces are repeated if said at least one measured error is greater than a predetermined threshold.
• a predetermined threshold it is possible to control the precision of fit of pre-cuts and clays on the three-dimensional model.
• the method according to the invention thus makes it possible to simplify the process of transferring a two-dimensional model onto a three-dimensional object and to reduce the risks of errors in laying precuts or cliches.
• the method according to the invention makes it possible to dispense with a validation step according to which the construction of a real model is necessary.
• FIG. 2 shows an example of an apparatus making it possible to implement the invention
• FIG. 3 illustrates certain steps of an exemplary algorithm for implementing a first part of the method according to the invention in order to model the three-dimensional object by a set of developable surfaces;
• FIGs 5 to 8 show illustrations of some of the steps shown in Figures 3 and 4.
• a central processing unit 215 such as a microprocessor, denoted CPU (Central Processing Unit);
• CPU Central Processing Unit
• the process according to the invention can be decomposed into two phases.
• a first phase aims at modeling the three-dimensional object by a set of developable surfaces, that is to say three-dimensional surfaces that can be represented in a plane, without deformation.
• a second phase has for object the transfer of the two-dimensional pattern on the developable surfaces modeled.
• FIG. 3 illustrates certain steps of an exemplary algorithm for implementing the first part of the method according to the invention in order to model the three-dimensional object by a set of developable surfaces.
• a first step consists in determining the part to be modeled (step 300), that is to say here the part on which the two-dimensional pattern must be transferred.
• a new surface is determined to produce an approximated three-dimensional model (step 305).
• the modeling surface is used instead of the surface of the three-dimensional object to be modeled to take into account the error introduced by the modeling of the three-dimensional object into developable surfaces, that is to say to take into account the difference in length between the theoretical starting surface and the developable surface.
• the modeling surface is a surface parallel to the surface of the three-dimensional object, located outside the surface of the three-dimensional object. The distance between the modeling surface and the real surface of the three-dimensional object is chosen according to the type of the three-dimensional object to be modeled.
• a set of developable surfaces is determined from the modeling surface (step 310).
• Each developable surface is determined by two reference curves of the modeling surface, the developable surface being constructed by the set of normal segments at both curves and whose ends belong to the two curves, forming a regulated surface.
• the developable surfaces can be constructed by any type of scanning supporting a segment on one or more curves.
• the reference curves of the modeling surface can in particular be determined by the intersection of planes with the modeling surface or by the shape of the two-dimensional pattern to be projected itself.
• FIG. 5 illustrates a modeling surface 500 comprising two curves 505-1 and 505-2 obtained by the intersection of the parallel planes 510-1 and 510-2 with the modeling surface 500.
• the developable surface generated by the curves 505-1 and 505-2 is the surface 515.
• the distance between the reference curves is preferably determined according to the complexity of the surface to be modeled. According to an advantageous embodiment, a default distance between two neighboring reference curves is used, this distance being reduced recursively as long as the difference between the modeling surface and the developable surface generated by these two reference curves is greater than a predetermined threshold (step 315). Thus, if the distance between the modeling surface and the developable surface generated by the two reference curves used is greater than a predetermined threshold, the distance between the two reference curves used is reduced and a new developable surface is calculated (the step 310 is repeated).
• FIGS. 5 to 8 have been generated from reference curves resulting from the intersection of vertical planes perpendicular to the longitudinal axis of the aircraft. These planes are here parallel and generate developable surfaces in the form of bands.
• the developable surfaces are then preferably developed and positioned in the same plane to facilitate the creation of trace files that can be used to produce precut or clichés.
• Figure 7 shows a set of developable and developed surfaces including characteristic points and projection of two-dimensional patterns.
• the creation of such files is an effective means of transmitting to a manufacturer of pre-cut or stencil precise and final data relating to each developable surface.
• Such files also make it possible to maintain a representation of precuts or clichés for a subsequent direct use, for example, to repaint the decorations of an aircraft.
• precut and precut are advantageously on machines capable of tracing and cutting adhesives such as pre-cut adhesive or mylar or other suitable media to provide tracing or masking on the three-dimensional object.

Landscapes

• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Pure & Applied Mathematics (AREA)
• Mathematical Optimization (AREA)
• Mathematical Physics (AREA)
• Mathematical Analysis (AREA)
• Algebra (AREA)
• Computer Graphics (AREA)
• Geometry (AREA)
• Software Systems (AREA)
• Theoretical Computer Science (AREA)
• Processing Or Creating Images (AREA)
• Numerical Control (AREA)
• Image Generation (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=38779562

Family Applications (1)

Country Status (9)

Families Citing this family (5)

Family Cites Families (8)

• 2007
  • 2007-04-26 FR FR0754720A patent/FR2915605B1/fr not_active Expired - Fee Related
• 2008
  • 2008-04-23 WO PCT/FR2008/000582 patent/WO2008145857A2/fr not_active Ceased
  • 2008-04-23 CA CA002684525A patent/CA2684525A1/en not_active Abandoned
  • 2008-04-23 EP EP08805501A patent/EP2145318A2/de not_active Withdrawn
  • 2008-04-23 US US12/597,359 patent/US20100060636A1/en not_active Abandoned
  • 2008-04-23 CN CN200880013698A patent/CN101836238A/zh active Pending
  • 2008-04-23 RU RU2009143678/08A patent/RU2468438C2/ru not_active IP Right Cessation
  • 2008-04-23 BR BRPI0809768-2A2A patent/BRPI0809768A2/pt not_active IP Right Cessation
  • 2008-04-23 JP JP2010504786A patent/JP2010525474A/ja active Pending

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events