A method for reconstructing surface meshes from measured data points is proposed. The points are obtained by laser scanning 3D shape measurement equipment. The method is based on "Implicit Function Reconstruction" method, in which the mesh is generated by iso-surfacing a potential field in 3D voxel space. A new approach for defining the potential field from the measured data points is used. Using this approach, a prototype system is developed for reconstructing meshes for complex objects.

The pattern of triangular meshes are important both for modeling and for rendering. It is desired that a user can change the mesh pattern without damaging its original shape. We propose an interactive remeshing method by which a user can specify the region to be remeshed and the pattern of triangles to be filled in the region. The proposed method is based of DSI (Discrete Smooth Interpolation) algorithm.

The purpose of this research is to suggest the method that interactively re-constructs approximate $G^1$ continuity for B-spline surface models, considering used particular in the field of computer graphics. It is for non-uniform B-spline surface model, once B-spline surface is subdivided to Bezier patches and whose control points near the B-spline boundary curve are modified. Later, B-spline control points are re-calculated with minimum square approximation method. Since each step is resolved itself into problem of linear equations without non-linear optimizing method, this method performs in short time.

Recently, animations with deforming objects have been frequently used in various computer graphics applications. Metamorphosis (or morphing) of three-dimensional objects is one of the techniques which realizes shape transformation between two or more existing objects. In this paper, we present an efficient framework for metamorphosis between two topologically equivalent, arbitrary meshes with the control of surface correspondences by the user. The basic idea of our method is to partition meshes according to the reference shapes specified by the user, whereby vertex-to-vertex correspondences between the two meshes can be specified. Each of the partitioned meshes is embedded into a polygonal region on the plane with harmonic mapping. Those embedded meshes have the same graph structure as their original meshes. By overlapping those two embedded meshes, we can establish correspondence between them. Based on this correspondence, metamorphosis is achieved by interpolating the corresponding vertices from one mesh to the other. We demonstrate that the minimum control of surface correspondences by the user generates sophisticated results of the interpolation be-tween two meshes.

We propose a 3D mesh-dragging method useful for intuitive, ancient geometric modeling of free-form polygonal models. With our method, the user can drag a part of a triangular mesh and change its position and orientation. This method is based on an adaptive remeshing procedure which evaluates the deformation of faces by dragging and properly modifies them by deleting or splitting with local topological operations. Therefore the mesh is automatically adjusted for dragging, and irregularity caused by dragging onto the mesh is no longer a concern. In addition, this method is local to the dragged portion, so its computation is ancient In this paper we describe our adaptive remeshing method and demonstrate some dragging examples.

This paper proposes a new mesh modeling scheme, called mesh fusion, based on three-dimensional (3D) mesh-based metamorphosis. We establish the attachment from a part of one mesh to a part of another with smooth boundaries, employing the traditional cutting and pasting operation in conjunction with a combination of meshes, applying the idea of 3D metamorphosis. We also offer an algorithm for adjusting two boundaries by using the combination of three geometrical operations rigid transformation, scaling and deformation. Our schematic offers a computation time swift enough that the user can create various shapes with interactive speed.

The objective of this research is to apply the subdivision surface for surface fitting problems when generating surfaces from data points or polyhedral models. The basic idea is to use the subdivision limit position (SLP) to adapt the control mesh of the subdivision surface to the data points. This method is not a time consuming process involving global optimization. It does, however, fail to capture local characteristics of data points. Consequently, the proposed method is not suitable for generating a surface that precisely interpolates the data points, but it will be useful for quickly generating a surface that captures the overall shape constituted by the data points. A prototype system has been developed to demonstrate several examples for purposes of evaluating the proposed method.

The purpose of this research is to develop methods to rapidly create smooth and detailed shape models from a rough triangular mesh (a polyhedron with triangular faces) for free-form shape design. In our previous work, a subdivision approach using the theory of local fitting a quadric surface to a triangular mesh was proposed. This approach can create smooth surface models but cannot add features such as valley and fillet to initial mesh. By ex tending this approach, new subdivision method which is able to both create smooth surface models and add detailed feature shapes is presented in this paper. New method consists of two steps, topological operations and decisions of vertex positions, and combinations of two steps are possible to create various feature shapes, including smooth shape.

We propose a new modeling and rendering system that enables users to construct 3D models with an interface that seems no different from sketching by hand, and that displays models in a sketch-like style, preserving the features of the user's strokes. We call this system 3D SKETCH. To reconstruct 3D objects from sketches, we limit the domain of renderable sketches and prepare a template for interpreting sketches. As long as a sketch can be matched to such a template, the system can reconstruct a mesh model from the sketch. The system collects information about strokes made, and uses that information for our rendering scheme. When that is accomplished, the designer can view the sketched object from different directions. Our goal is to make users feel as though they can draw their own sketches directly as 3D models.

We study a method for generating developments of polyhedral models, which are easily constructed with paper sheet. The easiness is evaluated in terms of the total length of edges which must be cut, the area of a rectangle circumscribing the development and the number of parts of development. Our goal is not for generating the optimal development but for generating a acceptable development quickly. Basically, generating a development corresponds to finding a spanning tree of face-edge graph of the polyhedral model. We propose two algorithms for traversing the face-edge graph, and four methods for setting costs representing the easiness of manual construction. We implemented an application which generates developments using this method and supports a user to construct paper models.