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KR-102964023-B1 - High-Speed Parametric Sampling System Based on Piecewise Polynomial Preprocessing

KR102964023B1KR 102964023 B1KR102964023 B1KR 102964023B1KR-102964023-B1

Abstract

A sampling system according to one embodiment of the present invention may be characterized by comprising: a parsing unit that receives a NURBS-based geometric file from a user terminal and extracts geometric information from the geometric file; a preprocessing unit that determines a basis function from the extracted geometric information and generates and stores an interval polynomial for the determined basis function; a sampling unit that selectively evaluates a basis function corresponding to a parameter interval using the interval polynomial to generate interval-specific sample points corresponding to the shape; and a transmission unit that combines the interval-specific sample points, converts them into drawing representation data, and transmits them to the user terminal.

Inventors

  • 권세규

Assignees

  • 메이크웍스(주)

Dates

Publication Date
20260512
Application Date
20251127

Claims (10)

  1. In a sampling system connected to a user terminal via a network, A parsing unit that receives a NURBS-based geometric file from a user terminal and extracts geometric information from the geometric file; A preprocessing unit that determines basis functions from extracted geometric information and generates and stores interval polynomials for the determined basis functions; A sampling unit that selectively evaluates basis functions corresponding to parameter intervals using interval polynomials to generate interval-specific sample points corresponding to the shape; and It includes a transmission unit that combines sample points by section, converts them into drawing representation data, and transmits them to a user terminal, Geometric information includes the degree of the NURBS, control points, knot vectors, and weights, and A sampling system characterized by a preprocessing unit that determines a basis function based on extracted order and knot vectors, and generates and stores an interval polynomial for each knot interval based on the determined basis function.
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  3. In paragraph 1, A sampling system characterized by a sampling unit that searches for knot intervals belonging to a parameter interval, selects a polynomial among interval polynomials that corresponds to the searched knot interval, and evaluates only d+2 valid basis functions (where d represents the degree of NURBS) for the parameter interval to generate sample points for each interval.
  4. In paragraph 3, A sampling system characterized by a sampling unit that searches for a knot interval to which a parameter interval belongs using a binary search method based on the fact that the knot vector is an ordered sequence, and evaluates the interval polynomial of the knot interval corresponding to the search result.
  5. In paragraph 1, A sampling system characterized by a preprocessing unit merging knot sequences by considering whether knot vectors are duplicated, and based on the merged knot sequences, dividing the interval polynomials of the basis functions to fit the merged knot intervals and rearranging them into piecewise polynomials for each interval.
  6. In paragraph 5, A sampling system characterized by a preprocessing unit creating and storing a mapping index table that mutually maps a merged knot interval and an interval polynomial, and a sampling unit selecting an interval polynomial by referring to the mapping index table.
  7. In paragraph 1, A sampling system characterized by a preprocessing unit that generates interval polynomials of basis functions step by step based on dynamic programming.
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  9. In paragraph 1, A sampling system characterized by a sampling unit that calculates the complexity of a parameter interval based on at least one of the curvature, slope change rate, or shape error of a curve corresponding to the parameter interval, and increases or decreases the generation density of sample points according to the complexity.
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Description

High-Speed Parametric Sampling System Based on Piecewise Polynomial Preprocessing The present invention relates to a sampling system, and more specifically, to a high-speed parametric sampling system using interval polynomial preprocessing that enables high-speed sampling of NURBS (Non-Uniform Rational B-Spline) based files. In the fields of CAD (Computer-Aided Design), graphic modeling, mechanical design, architectural design, animation, and rendering, NURBS (Non-Uniform Rational B-Spline)-based curve and surface representation methods are widely used to precisely represent the geometry of objects. NURBS is defined by control points, degrees, knot vectors, and weights, and offers the advantage of being able to flexibly and accurately represent geometries of varying complexity. Generally, in order to render NURBS curves or surfaces or perform subsequent processing, a sampling process for parameters is required. When sampling, basis functions corresponding to each parameter value are calculated, and then sample points are generated by combining the basis functions with control points (and weights). However, in conventional methods, NURBS basis functions are defined by recursive equations, requiring iterative basis function calculations for each parameter value. This leads to a problem where the total computation time increases significantly when complex geometries or multiple sampling points are required. Furthermore, although NURBS basis functions consist of mutually distinct polynomials for intervals divided by knot vectors, it was common practice to perform calculations on the entire basis function without considering the interval to which the parameter belongs, or to repeatedly evaluate basis functions beyond what is necessary. The above-mentioned computational method can cause bottlenecks during the sampling process in shape models containing complex free curves or multiple curves, such as CAD data, and is a cause of performance degradation, particularly in application environments such as real-time rendering, visualization servers, web-based CAD services, or large-scale shape analysis. Therefore, a technical solution is required to significantly improve the sampling speed. A brief description of each drawing is provided to help to better understand the drawings cited in this specification. FIG. 1 is a block diagram illustrating a sampling system according to one embodiment of the present invention. FIG. 2 is a flowchart of an implementation of a sampling system according to one embodiment of the present invention. The present invention is capable of various modifications and may have various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, and it should be understood that the present invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. In describing the present invention, if it is determined that a detailed description of related prior art may unnecessarily obscure the essence of the present invention, such detailed description is omitted. Additionally, numbers used in the description of this specification (e.g., 1st, 2nd, etc.) are merely identification symbols to distinguish one component from another. In addition, when a component is described in this specification as being "connected" or "connected" to another component, it should be understood that the component may be directly connected to or directly connected to the other component, but unless otherwise specifically stated, it may also be connected or connected through another component in between. In addition, components expressed as '~part' in this specification may consist of two or more components combined into a single component, or a single component may be divided into two or more components according to more detailed functions. Furthermore, each component described below may additionally perform some or all of the functions performed by other components in addition to the primary function it is responsible for, and it goes without saying that some of the primary functions performed by each component may be exclusively performed by other components. Hereinafter, embodiments based on the technical concept of the present invention will be described in detail in turn. FIG. 1 is a block diagram illustrating a sampling system according to one embodiment of the present invention, and FIG. 2 is a flowchart illustrating an implementation of a sampling system according to one embodiment of the present invention. As illustrated in FIGS. 1 and 2, a sampling system (100) according to one embodiment of the present invention may be connected to a user terminal (10) via a network (1), may include a parsing unit (101), a preprocessing unit (102), a sampling unit (103), and a transmission unit (104), and may be applied to a cl