Issue 1
https://diglib.eg.org:443/handle/10.2312/72
Regular Issue2021-04-12T23:27:37ZAn Efficient Algorithm for Line Clipping by Convex and Non-convex Polyhedra in E3
https://diglib.eg.org:443/handle/10.2312/7013
An Efficient Algorithm for Line Clipping by Convex and Non-convex Polyhedra in E3
Skala, Vaclav
A new algorithm for clipping lines against convex polyhedron with O(N) complexity is given with modification for non-convex polyhedron. The suggested algorithm is faster for higher number of facets of the given polyhedron than the traditional Cyrus-Beck s algorithm. Some principal results of comparison of all algorithms are shown and give some ideas how the proposed algorithm could be used effectively.
1996-01-01T00:00:00ZSurface Reconstruction from Unstructured 3D Data
https://diglib.eg.org:443/handle/10.2312/7012
Surface Reconstruction from Unstructured 3D Data
Algorri, Maria-Elena; Schmitt, Francis
Building 3 0 models from unstructured data is a problem that arises increasingly as new 30 scanning technology is able to produce large and complex databases of full 3 0 information. Huge efforts put into segmenting entire sets of 20 images demand robust tools that are then able to reconstruct any arbitrary 30 surface segmented from the images. In this paper we propose an algorithmic methodology that automatically produces a surface from a set of points in ?3 about which we have no topological knowledge. Our method uses a spatial decomposition and a surface tracking algorithm to produce a rough approximation S of the unknown manifold S. The produced surface S serves as a robust initialisation for a physically based modeling technique that yields the fine details of S and so improves the quality of the reconstruction.
1996-01-01T00:00:00ZAccelerated Evaluation of Box Splines via a Parallel Inverse FFT
https://diglib.eg.org:443/handle/10.2312/7011
Accelerated Evaluation of Box Splines via a Parallel Inverse FFT
McCool, Michael D.
Box splines are a multivariate extension of uniform univariate B-splines. Direct evaluation of a box spline basis function can he difficult but they have a relatively simple Fourier transform and can therefore be evaluated with an inverse FFT. Symmetry recursive evaluation of the coefficients, and parallelization can be used to improve absolute performance. A windowing function can also he used to reduce truncation artifacts. We explore all these options in the context of a high-performance parallel implementation. Our goal is the provision of an empirical touchstone for the inverse FFT evaluation of box spline basis functions, for eventual application to forward projection (splat-based) volume rendering.
1996-01-01T00:00:00ZScripting Interactive Physically-Based Motions with Relative Paths and Synchronization
https://diglib.eg.org:443/handle/10.2312/7010
Scripting Interactive Physically-Based Motions with Relative Paths and Synchronization
Lamouret, Alexis; Gascuel, Marie-Paule
This paper presents a novel approach for facilitating the use of physically based models by animators. The idea is to let the user guide motion at a high level of control by giving approximate desired trajectories and synchronization constraints between the objects over time, while a simulation module computes the final motion, dealing with collision detection and response, and enhancing realism.The objects, which are either isolated or components of an articulated structure, are guided through the specification of key-positions and orientations, defined by coordinates that can be fixed or relative to another object. The animation sequence is scripted by specifying a graph of synchronization constraints between objects over time. During the animation, objects automatically regulate their speed in order to meet these constraints.
1996-01-01T00:00:00Z