Data Compression

Data Compression Method for Trimmed Surfaces Based on Surface Fitting with Maintaining G1 Continuity with Adjacent Surfaces

Yuta MURAKI, Katsutsugu MATSUYAMA, Kouichi KONNO and Yoshimasa TOKUYAMA


Trimmed surfaces are one of the versatile shape representations. When 3D data is put into circulation on the Internet, data size reduction for trimmed surfaces is an important issue in digital engineering. In this paper, we propose a data compression method based on surface fitting method. Our method enables efficient surface data compression by using the surface fitting method. In our method, the surface fitting method is applied to a closed region surrounded by the boundary edges of a 3D shape model. With the approximation method that uses boundary curves and sample points based on a tangent plane at the boundary edges, the surface fitting method can also be applied to shapes with holes or concave shapes. In order to maintain G1 continuity with adjacent surfaces, the cross boundary derivatives obtained by the surface interpolation method are applied to the connection section with adjacent surfaces. When a surface is generated in good accuracy, the original surface element can be deleted and data size can be drastically reduced. The deleted surface element can be reconstructed from the boundary edges using our method.