Curve network modeling
AssigneeSilicon Graphics, Inc.
InventorsSriram Dayanand, Richard E. Rice
Life of this patent
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Abstract
A method of modeling complex surface models using a network of intersecting non-uniform rational B-spline curves. Topological information of the curve network and interpolating surfaces to the network of curves are automatically generated. Different levels of continuity between surface patches are enforced. Surface patches of three and four sides and positional, tangent or curvature continuity between the patches are provided. Using a constrained minimization process, arbitrary, non-uniform B-spline curves may be used to manipulate the shape of the surfaces interpolating the curve network without violating the continuity conditions enforced during the generation of the surface patches allowing for very complex three-dimensional shapes to be modeled using the method.
Claims27
A method of computer surface modeling comprising:
- storing in a computer memory a curve network of intersecting nonhomogenous curves;
- and
- automatically determining faces from the curve network, the faces having an arbitrary number of sides, wherein the faces are automatically determined by a topology estimation routine that searches coupled curve segments lying between intersections of the curves.
A method of computer surface modeling comprising:
- storing in a computer memory a curve network of intersecting nonhomogeneous curves, and an interpolated surface for a face of the curve network, the face having an arbitrary number of sides;
- and
- modifying the interpolated surface in response to manipulation of a control curve, the control curve being separate from the curves of the curve network, wherein the modifying step further comprises:
- sampling the control curve at a sampling point,
- coupling the sampling point to a projection point on the interpolated surface, and
- controlling the shape of the interpolated surface at the projection point based upon the coupled sampling point.
A method of computer surface modeling comprising:
- storing in a computer memory a curve network of intersecting nonhomogeneous curves defining faces and edges, the faces having an arbitrary number of sides;
- setting a continuity constraint at an edge of a first one of the faces;
- and
- automatically generating and storing in the computer memory an interpolated curved surface for the first face based on the set continuity constraint.
An interface method for use with a computer-based surface modeling program, comprising:
- enabling a user to define interactively nonhomogeneous curves forming portions of a curve network associated with a surface being modeled;
- and
- automatically in response to the defining of curves by the user, determining faces associated with the curves, the faces having an arbitrary number of sides, wherein the faces are automatically determined by a topology estimation routine that searches coupled curve segments lying between intersections of the curves.
An interface method for use with a computer-based surface modeling program, comprising:
- enabling a user to manipulate interactively a curved control element shown on a display;
- and
- automatically altering a surface being modeled in response to the user's manipulations of the curved control element, the surface comprising a network of intersecting curves and the control element being separate from the curves of the network, wherein faces associated with the curves are automatically determined by a topology estimation routine that searches coupled curve segments lying between intersections of the curves.
Dependencies are inferred from the claim text.