Details of a Researcher - MATSUYAMA Katsutsugu

MATSUYAMA Katsutsugu

写真a

Affiliation	IWATE University Faculty of Science and Engineering Department of Systems Innovation Engineering Studies in Computer, Intelligence and Media Sciences
Position	Professor

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Campus Career 【 display / non-display 】

2023.02

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Now

IWATE University Faculty of Science and Engineering Professor [Duty]
2017.09

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2023.01

IWATE University Faculty of Science and Engineering Associate Professor [Duty]

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Course Subject 【 display / non-display 】

2011

Computer Animation
2011

Network Laboratory
2012

3D Shape Representation
2012

Computer Animation
2011

Hardware Laboratory

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Published Papers 【 display / non-display 】

Spherical Style Deformation on Single Component Models

Xuemei Feng, Qing Fang, Kouichi Konno, Zhiyi Zhang, Katsutsugu Matsuyama

IEICE Transactions on Information and Systems E106-D ( 11 ) 1891 - 1905 2023.11 [Refereed]

International Conference Proceedings Multiple authorship

In this study, we present a spherical style deformation algorithm to be applied on single component models that can deform the models with spherical style, while preserving the local details of the original models. Because 3D models have complex skeleton structures that consist of many components, the deformation around connections between each single component is complicated, especially preventing mesh self-intersections. To the best of our knowledge, there does not exist not only methods to achieve a spherical style in a 3D model consisting of multiple components but also methods suited to a single component. In this study, we focus on spherical style deformation of single component models. Accordingly, we propose a deformation method that transforms the input model with the spherical style, while preserving the local details of the input model. Specifically, we define an energy function that combines the as-rigid-as-possible (ARAP) method and spherical features. The spherical term is defined as ℓ2-regularization on a linear feature; accordingly, the corresponding optimization can be solved efficiently. We also observed that the results of our deformation are dependent on the quality of the input mesh. For instance, when the input mesh consists of many obtuse triangles, the spherical style deformation method fails. To address this problem, we propose an optional deformation method based on convex hull proxy model as the complementary deformation method. Our proxy method constructs a proxy model of the input model and applies our deformation method to the proxy model to deform the input model by projection and interpolation. We have applied our proposed method to simple and complex shapes, compared our experimental results with the 3D geometric stylization method of normal-driven spherical shape analogies, and confirmed that our method successfully deforms models that are smooth, round, and curved. We also discuss the limitations and problems of our algorithm based on the experimental results.
A New Method of Refitting Mixture Lithic Materials by Geometric Matching of Flake Surfaces

Xi Yang, Katsutsugu Matsuyama, Kouichi Konno

The Journal of The Society for Art and Science 15 ( 4 ) 167 - 176 2016.11 [Refereed]

International Conference Proceedings Multiple authorship

In Japan, lithic materials are very important evidences of human activity research in the Palaeolithic and Jomon periods, while refitting lithic materials is a complex and hard task. In our previous research, it is possible to refit lithic materials from a single stone core, while it is impossible to refit them from multiple stone cores. This paper proposes a new method for refitting mixture lithic materials by matching flake surfaces. Each of the input point clouds of lithic materials is segmented and simplified to obtain flake surfaces. Then, according to several refitting principles in archeology, the lithic materials are matched starting from a stone core by searching the best matching flake surface. The flake surfaces of matched lithic materials are reconstructed, and the matching process is repeated until all data are matched. The implementation of the new method can obtain good refitting results for experimental examples.
Unfolding a Point Cloud on Relic's Surface for Surface Pattern Visualization

Zepeng Wang, Katsutsugu Matsuyama, Kouichi Konno

The Journal of The Society for Art and Science 15 ( 2 ) 32 - 42 2016.06 [Refereed]

International Conference Proceedings Multiple authorship

Developable surfaces are important for representing and understanding geometric features of 3D models. Some methods are required that surface pattern of a relic should be easily observed in archaeology area. This paper introduces a system to visualize the development of relic's surface pattern based on points, which does not require reconstruction of a mesh model and relies only on the information of points to develop the relic's surface. After a point cloud of a relic is segmented to separate sections, points of each section are projected to a developable surface, then the points of relic's surface are unfolded into an image plane. In our method, the number of segmentations can be controlled by an archaeologist in an interactive interface. The more segmentations a point cloud is divided into, the higher precision the image plane is shown in adjacent area. To observe the surface pattern easily, a developed plane can be interactively rotated on the prime meridian, which is extracted from a relic's surface. This approach can help archaeologists move a specific area of interest to the center of the relics.
A Framework for Manipulating Multi-Perspective Image Using A Parametric Surface

Katsutsugu MATSUYAMA, Kouichi KONNO

ACM Digital Library 2016.05 [Refereed]

Bulletin of University, Institute, etc. Multiple authorship
Generating a reference model of the surface with a hole for downstream process

Gulibaha Silayi, Tsutomu Kinoshita, Katsutsugu Matsuyama, Kouichi Konno

Computer-Aided Design and Applications 13 ( 4 ) 530 - 537 2016.01 [Refereed]

Academic Journal Multiple authorship

The value of 3D CAD models is continuously increasing in downstream processes. The more extensive use of a 3D model outside traditional design and manufacturing is trending now. To distribute 3D data quickly to downstream departments is significant boosts to product quality, production costs, and delivery to markets. Unfortunately, interoperability causes poor communication since downstream applications rely on the reusability and interoperability of CAD models. However, 3D CAD data size for expressing precise forms tends to be big and time-consuming for computation, which may interfere in the communication. In addition, downstream processes emphasize surface smoothness more than precision. Therefore, this paper describes the reconstruction method of a smooth surface by integrating the advantages of Gregory and B-spline surfaces. In this paper, a new surface representation is proposed. Two surfaces are connected with G1-continuity by using the control points at the common boundary obtained from joining equations. The internal control point that is not connected to the boundary curve is obtained from the least squares approximation method. The proposed method is applicable to shapes with a hole.