An evaluation of reconstruction filters for a path-searching task in 3D

The choice of reconstruction filter used to interpolate between sample points when generating images from volumetric data sets can have an impact on image quality. There are a range of reconstruction filters as well as methods to determine the quality of these filters. While it is well documented that stereoscopy can improve the performance of spatial search tasks, it is not clear how artifacts introduced by the choice of reconstruction filter will impact the performance of these tasks. In this study we report the results of a path-tracing experiment where we assess the effectiveness of stereoscopy and three reconstruction filters in terms of accuracy and response time. Our results suggest that the reconstruction filter can have a significant effect on path-tracing tasks and that stereoscopy can significantly improve accuracy results whilst slightly increasing response time

Tree-based Triangle Mesh Connectivity Encoding

We present a divide and conquer algorithm for triangle mesh connectivity encoding. As the algorithm traverses the mesh it constructs a weighted binary tree that holds all information required for reconstruction. This representation can be used for compression.We derive a new iterative single-pass decoding algorithm, and we show how to exploit the tree data structure for generating stripifications for efficient rendering that come with a guaranteed cost saving

Polygonal decompositions of quadrilateral subdivision meshes

We study a polygonal decomposition of the 1-ring neighborhood of a quadrilateral mesh. This decomposition corresponds to the eigenvectors of a matrix with circulant blocks, thus, it is suitable for the study of subdivision schemes. First, we calculate the extent of the local mesh area we have to consider in order to get a geometrically meaningful decomposition. Then we concentrate on the Catmull-Clark scheme and decompose the 1-ring neighborhood into 2n planar 2n-gons, which under subdivision scheme transform into 4n planar n-gons coming in pairs of coplanar polygons and quadruples of parallel polygons. We calculate the eigenvalues and eigenvectors of the transformations of these configurations showing their relation with the tangent plane and the curvature properties of the subdivision surface. Using direct computations on circulant-block matrices we show how the same eigenvalues can be analytically deduced from the subdivision matrix

A Divide and Conquer Algorithm for Triangle Mesh Connectivity Encoding

We propose a divide and conquer algorithm for the single resolution encoding of triangle mesh connectivity. Starting from a boundary edge we grow a zig-zag strip which divides the mesh into two submeshes which are encoded separately in a recursive process. We introduce a novel data structure for triangle mesh encoding, a binary tree with positive integer weights assigned to its nodes. The length of the initial strip is stored in the root of the binary tree, while the encoding of the left and right submesh are stored in the left and right subtree, respectively. We find a simple criterion determining which objects of this data structure correspond to triangle meshes. As the algorithm implicitly traverses the triangles of the mesh, it can be classified into the family of Edgebreaker like encoding schemes. Hence, the compression ratios, both in the form of theoretical upper bounds and practical results are similar to the Edgebreaker's, while the simplicity and flexibility of the algorithm makes it particularly suitable for applications where the connectivity encoding is only a small part of the problem at hand