Abstract: The invention is directed to a computer program product, a computer system, computer apparatus and a computer-implemented method for creating a parametric surface. The invention provides a base mesh having a plurality of outer or inner vertices with valence greater than two. The vertices define faces and at least one of the vertices is an extraordinary vertex. The invention converts faces of the base mesh into parametric elementary surfaces and trims at least one of said parametric elementary surfaces located in the vicinity of the extraordinary vertex. Trimming is performed according to: (i) at least two parametric elementary surfaces adjacent to a subject parametric elementary surface; and (ii) the base mesh. Next the invention constructs at least one parametric elementary surface, adjacent to the trimmed parametric elementary surface, wherein the resulting parametric elementary surfaces form the parametric surface.

Abstract: The invention is directed to a method for creating a parametric surface symmetric with respect to a given symmetry operation (20). The invention method: (i) identifies a mesh pattern (15a); (ii) creates a base mesh (15s) from the mesh pattern, according to a symmetry operation; (iii) subdivides the base mesh, at a given order, into a subdivided mesh defining elementary faces; and (iv) forms the parametric surface (16s) according to said faces. The base mesh is symmetric with respect to the symmetry operation such as a reflection symmetry. The invention further concerns computer program product and systems implementing the method according to the invention.

Abstract: Several elements are displayed on a computer display. The user is provided with a haptic device, for moving a cursor over the display. Distances between the cursor and the various elements are computed; the element with the smallest distance is highlighted on the display. When the user moves the haptic device, the identified element is changed, according to the distance between the cursor and the various elements. The user selects the identified element by actuating a select button. The invention makes it possible for the user to select one of the displayed elements, without having to move the cursor over the element to be selected. No prior knowledge of the shape of the elements is required for carrying out the selection process.

Abstract: A curve is created in a computer-aided design system, based on a set of points inputted by the user. A polyline is computed and the curvature envelope along said polyline is computed to determine particular points (A0, A1, A2, A3, A4, A5) on thepolyline, which are extrema of curvature. Segmenting points (M0,1, M1,2, M2,3, M3,4, M4,5) are selected between pairs of particular points. A curve passing through the particular segmenting points is computed and is fitted to thepolyline. The process provides a curve that is well fitted to the set of points and does not require high skills from the user.

Abstract: The invention is directed to a computer program product, a computer system, computer apparatus and a computer-implemented method for creating a parametric surface. The invention provides a base mesh having a plurality of outer or inner vertices with valence greater than two. The vertices define faces and at least one of the vertices is an extraordinary vertex. The invention converts faces of the base mesh into parametric elementary surfaces and trims at least one of said parametric elementary surfaces located in the vicinity of the extraordinary vertex. Trimming is performed according to: (i) at least two parametric elementary surfaces adjacent to a subject parametric elementary surface; and (ii) the base mesh. Next the invention constructs at least one parametric elementary surface, adjacent to the trimmed parametric elementary surface, wherein the resulting parametric elementary surfaces form the parametric surface.

Abstract: The invention is directed to a method for creating a parametric surface symmetric with respect to a given symmetry operation (20). The invention method: (i) identifies a mesh pattern (15a); (ii) creates a base mesh (15s) from the mesh pattern, according to a symmetry operation; (iii) subdivides the base mesh, at a given order, into a subdivided mesh defining elementary faces; and (iv) forms the parametric surface (16s) according to said faces. The base mesh is symmetric with respect to the symmetry operation such as a reflection symmetry. The invention further concerns computer program product and systems implementing the method according to the invention.

Abstract: This invention presents methods and systems for generating and handling a harmonized network of points. More generally, this invention reorganizes and optimizes a network of points in terms of spatial distribution regularity. Implementations may allow users to manipulate the network of points while maintaining the organization of the network of points. The network of points can define a surface, which can include Béziers and Nurbs three-dimensional surfaces. The surface can be used in a CAD system.

Abstract: A method and system for indicating curve connection continuity information in a graphical design system comprises steps and apparatus for determining values for measures of G1, G2, and G3 continuity at a junction point between curves. The continuity values are selectively displayed in a graphical display as respective tags adjacent or otherwise associated with the junction point at issue. The tags are updated as the shape of the curves are altered to provide a designer with a substantially real-time indication of the continuity of the curve junction. The display format of the tags can be altered to indicate when the respective continuity measure is within a predefined continuity tolerance level.

Abstract: Several elements are displayed on a computer display. The user is provided with a haptic device, for moving a cursor over the display. Distances between the cursor and the various elements are computed; the element with the smallest distance is highlighted on the display. When the user moves the haptic device, the identified element is changed, according to the distance between the cursor and the various elements. The user selects the identified element by actuating a select button. The invention makes it possible for the user to select one of the displayed elements, without having to move the cursor over the element to be selected. No prior knowledge of the shape of the elements is required for carrying out the selection process.

Abstract: A curve is created in a computer-aided design system, based on a set of points inputted by the user. A polyline is computed and the curvature envelope along said polyline is computed to determine particular points (A0, A1, A2, A3, A4, A5) on thepolyline, which are extrema of curvature. Segmenting points (M0,1, M1,2, M2,3, M3,4, M4,5) are selected between pairs of particular points. A curve passing through the particular segmenting points is computed and is fitted to thepolyline. The process provides a curve that is well fitted to the set of points and does not require high skills from the user.

Abstract: This invention presents methods and systems for generating and handling a harmonized network of points. More generally, this invention reorganizes and optimizes a network of points in terms of spatial distribution regularity. Implementations may allow users to manipulate the network of points while maintaining the organization of the network of points. The network of points can define a surface, which can include Beziers and Nurbs three-dimensional surfaces. The surface can be used in a CAD system. In one aspect of this invention, a smoothing algorithm is applied to the surface adjusting internal points in the network based on the extremity points. Local planes are detected in the network, and if available, are used to further smooth the internal points in the network. In another aspect of this invention, local planes are detected in the network, and if available, are used to constrain internal points in the network.

Abstract: A method and system for indicating curve connection continuity information in a graphical design system comprises steps and apparatus for determining values for measures of G1, G2, and G3 continuity at a junction point between curves. The continuity values are selectively displayed in a graphical display as respective tags adjacent or otherwise associated with the junction point at issue. The tags are updated as the shape of the curves are altered to provide a designer with a substantially real-time indication of the continuity of the curve junction. The display format of the tags can be altered to indicate when the respective continuity measure is within a predefined continuity tolerance level.