Ahmad H. Nasri

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This paper presents a generalization of non-uniform B-spline surfaces called T-splines. T-spline control grids permit T-junctions, so lines of control points need not traverse the entire control grid. T-splines support many valuable operations within a consistent framework, such as local refinement, and the merging of several B-spline surfaces that have(More)
One of the central issues in computer-aided geometric design is the representation of free-form surfaces which are needed for many purposes in engineering and science. Several limitations are imposed on most available surface systems: the rectangularity of the network describing a surface and the manipulation of surfaces without regard to the volume(More)
Given an n-sided region bounded by a loop of n polylines, we present a general algorithm to fill such a region by a quad mesh suitable for a subdivision scheme. Typically, the approach consists of two phases: the topological phase and the geometrical phase. In the first part, the connectivity of the mesh is based on determining a partitioning of the region(More)
The volume of a solid enclosed by a recursive subdivision surface can be approximated based on the closedform representation of regular parts of the subdivision surface and a tight estimate of the local convex hull near e.xtraordinary points. The approach presented is efficient, i.e. non-exponential, and robust in that it yields rapidly contracting error(More)
A method for subdividing polygonal complexes and identifying conditions to control their limit curves is presented. A polygonal complex is a sequence of panels where every two adjacent panels share one edge only. We formulate this problem and establish a general theory which has a number of applications in CAGD such as the generation of subdivision surfaces(More)
Recursive subdivision is receiving a great deal of attention in the deenition of B-spline surfaces over arbitrary topology. The technique has recently been extended to generate interpolating surfaces with given normal vectors at the interpolated vertices. This paper describes an algorithm to generate recursive subdivision surfaces that interpolate B-spline(More)