Papers by Vladimir Savchenko
The Visual Computer, 1995
Geometric modeling using continuous real functions of several variables is discussed. Modeling co... more Geometric modeling using continuous real functions of several variables is discussed. Modeling concepts include sets of objects, operations and relations. An object is a closed point set of n-dimensional Euclidean space with a defining inequality f x x x n (, ,...,) 1 2 0 ≥. Transformations of a defining function are described for the set-theoretic operations, blending, offsetting, bijective mapping, projection, Cartesian product and metamorphosis. Inclusion, point membership and intersection relations are described. In the implemented interactive modeling system, we use highlevel geometric language that provides extendibility of the modeling system by input symbolic descriptions of primitives, operations and predicates. This approach supports combinations of representational styles, including constructive geometry, sweeping, soft objects, voxel-based objects, deformable and other animated objects. Application examples of aesthetic design, collisions simulation, NC machining, range data processing, and 3D texture generation are given.
This paper presents an approach to realize a tool for interactive and intuitive deformation of 3D... more This paper presents an approach to realize a tool for interactive and intuitive deformation of 3D shapes, to be used, for example as a character animation tool. The approach combines a fast algorithm for 3D free form deformation that employs compactly supported radial basis function (CSRBF) with a high degrees-of-freedom input device of hand joint angles, namely, the CyberGlove. While shape deformation algorithm by using CSRBF allows for fast and reasonable shape deformations, it is not a simple task to position the CSRBF so that desired shape deformations can be created. In our approach, the 10 CSRBF are attached to the tip of the fingers of the CyberGlove worn on both hands of the users. This allows the user an intuitive manipulation of 3D shapes in a manner somewhat similar to clay modeling. While the shape deformation algorithm does not produce physically accurate deformation, the deformation is fast, plausible and quite useful. For example, using a 32k polygon mesh, a deformati...
In this paper, we present a new technique called Trapezium Drawing to improve surface mesh qualit... more In this paper, we present a new technique called Trapezium Drawing to improve surface mesh quality while maintaining the essential surface characteristics. In contrast to previous methods we do not tend to preserve new mesh vertices on the original discrete surface. Instead our approach allows keeping new mesh close to the surface approximated by the initial mesh. All operations are performed directly on the surface. As a result our technique is robust and runs at interactive speeds. It can be applied to triangular and quadrilateral meshes iteratively. Various quantitative measures are presented to demonstrate the effectiveness of proposed technique.
Despite their long history, radial basis functions have never really become a widely used tool fo... more Despite their long history, radial basis functions have never really become a widely used tool for surface generation and image/surface modifications. This paper presents work in progress, and continues a project devoted to developing a system for shape modeling based on implementation of RBF technology. Experimental results are included to demonstrate the functionality of our mesh-modeling tool. In particular, we consider such applications as surface reconstruction, surface retouching, animation, and shape smoothing. Also we discuss an algorithm for local mesh generation and polygon simplification.
Most mesh processing filters (including remeshing, simplification, and subdivision) affect vertic... more Most mesh processing filters (including remeshing, simplification, and subdivision) affect vertices of the mesh. Vertices coordinates are modified, new vertices are added and some original ones are removed, with the result that the shape of the original surface is changed. While a great deal of research is concentrated on preservation of surface shape during some mesh processing, there is no general tool that can be used for surface reconstruction at post processing stage. To the best of our knowledge, this paper is the first one to present a restoring algorithm that allows to “repair” output of various mesh processing filters. The proposed scheme is straightforward way to put “off-surface” vertices of the deformed mesh back to the original smooth shape. It does not require any surface parameterization and is based on normal analysis. The procedure is demonstrated by using it as post processing tool after applying local node movement and simplification algorithms. However, the techn...
This invited talk describes basics and current developments of an approach to modeling volumetric... more This invited talk describes basics and current developments of an approach to modeling volumetric and multidimensional objects using HyperFun language and associated software (1). HyperFun is a modeling language designed to be a high-level tool suitable for specifying functionally based (F-rep) models (2). While being minimalist, it supports all main notions of F-rep. HyperFun is also intended to serve as a lightweight exchange protocol to support platform independence and Internet-based collaborative modeling. Software tools for HyperFun are being developed in an open source project manner by the team of collaborators from several countries. Application software deals with HyperFun models through the language interpreter or using the compiler to C/C++/Java and a set of utilities of the HyperFun API. The project description and current application tools (HyperFun polygonizer and plug-in to POVRay) are available at the devoted Web site http://www.hyperfun.org. A volume can be thought...
The recent advent of video-based tracking technologies allowed to bring natural head motion to an... more The recent advent of video-based tracking technologies allowed to bring natural head motion to any 3D application, including games. However, video tracking is a CPU-intensive process, which may have a negative impact on game performance. In this work, we examine this impact for different types of 3D content, using a game prototype built with two advanced components, CryENGINE2 platform and faceAPI head tracking system. Our findings indicate that cost of video tracking is negligible. We provide detail on our system implementation and performance analysis. Also, we present a number of new techniques of controlling user avatars in social 3D games, based on head motion.
SN Applied Sciences
Origami art has found numerous engineering applications. Many studies show that folding structure... more Origami art has found numerous engineering applications. Many studies show that folding structures are the source of the desired system characteristics. In this article, we discuss the design of a beach umbrella based on the principles of origami and the study of its optical and mechanical properties. The main requirements for the designed model are that it should reduce the harmful effects of solar radiation on human health, should be compact for storage, and not collapse in the wind. To demonstrate the optical and mechanical properties of the designed model, the developed recursive ray tracing algorithm is used to simulate the propagation of light rays through the designed paper origami-based structure and the numerical simulations are performed using the commercial software ANSYS and LS-DYNA to study the behavior of the designed origami-based structure under lateral forces as well as its folding behavior. A combination of ray tracing approach and an optimization technique based on the genetic algorithm for modifying the developed model is also discussed. Simulation results are presented in the illustrations.
2014 IEEE Conference on Biomedical Engineering and Sciences (IECBES), 2014
In this work we investigate the effect of diffusive voltage and current couplings between natural... more In this work we investigate the effect of diffusive voltage and current couplings between natural pacemaker oscillators in the heterogeneous coupled oscillator model of ECG signals. We study the synchronization behavior of the oscillator system for normal and fast cardiac sinus rhythms and reproduce different mode-locked cases which correspond to known incomplete atrioventricular blocks. The obtained results may help to choose reasonable coupling configurations to study heart rhythm dynamics coupled oscillator models.
The Visual Computer, 2015
We present a non-iterative approach to visually plausible rendering of multi-layered clothes, aim... more We present a non-iterative approach to visually plausible rendering of multi-layered clothes, aimed mainly at human figures dressed in multiple garments. The problems we address are cloth interference and z-fighting. Our approach is based on numbering layers of clothing and then using recursive ray tracing to keep them in order. Instead of developing a new physically based technique, such as collision detection/response schemes or particle systems, we develop a visualization technique to complement existing physically based methods, greatly reducing the required precision and, thus, the computational cost.
We describe a novel algorithm for local approximation of scattered surface points, implementing a... more We describe a novel algorithm for local approximation of scattered surface points, implementing a 2D finite element interpolation algorithm in combination with approximation of coordinates using quadrics for conversion of noisy data to sufficiently smooth data sets. The applied methods and time performance of the developed algorithm are discussed. Experimental results are included to demonstrate the functionality of our approximation technique.
The Proceedings of The Computational Mechanics Conference
Ptesent'ed researbh' concerng in6deling lof different 'mesh quality.parameters for fumher improve... more Ptesent'ed researbh' concerng in6deling lof different 'mesh quality.parameters for fumher improvement of the mesh .elements. Basic case pf niangulation is･considered for produFing the mesh elgments with uniforrn distribution of the aspect ratio values.' This approach allows creating different applicable to a mesh processing algorithms, based Qn ..qudsi-statistical modeling proPosed at the Preli.mi, p,ary' step.,.V4rious. form'i las gah bg deriyed for calculation 6f new values of the 'mesh quality pdrarneter. Vertex dirdcijon inovement with the distribution tak,gh' in the mbdeling step is cpntfo11ed.' ''
The Proceedings of The Computational Mechanics Conference
Optimization ofmesh quality with preserving surface characteristics and features .t ' ' ' tt t t ... more Optimization ofmesh quality with preserving surface characteristics and features .t ' ' ' tt t t t ' 'LSemen6"a'' '' ''/
Geometric Modeling: Theory and Practice, 1997
ABSTRACT
In the paper we studied capabilities of using advanced geometric operations developed by us inan ... more In the paper we studied capabilities of using advanced geometric operations developed by us inan interactive environment for volume modeling having applied haptic interface for engraving.Also we discussed limitations that underlie actions for human users.Keywords: volume graphics, virtual reality, sculpting, haptic rendering1. IntroductionThe 1990's have seen a growing interest in development of volume sculpting systems. Byvolume sculpting we understand the
First International Symposium on Cyber Worlds, 2002. Proceedings., 2000
This paper introduces a basic technique for drawing non-photo realistic images of volume models. ... more This paper introduces a basic technique for drawing non-photo realistic images of volume models. The turtle graphics approach to imitate painting operations is implemented in 3D space. Objects are defined by sets of scattered range data. Analytically (that is; functionally represented) and procedurally defined geometric objects can also be used. The proposed technique is described in detail and painting examples that demonstrate its applicability to non-photo realistic rendering or hatching are provided.
Proceedings of the third ACM symposium on Solid modeling and applications - SMA '95, 1995
Ilk paper ck!als wi[h an inlcrac[ivc scuipling [cchniquc based on local tfcformsil{ms I)] a cons[... more Ilk paper ck!als wi[h an inlcrac[ivc scuipling [cchniquc based on local tfcformsil{ms I)] a cons[ruc[ivc solid by a se[ of arbitrary potnts that arc assumed (O belong [o Ihc rcsullanl surface. I<eprcsenlation of a solid by a real continuous function of three variables is used, 'Ilc [heory of R-functions is applied for scltheoretic operatlorrs on solids. in contrast m the existing methods based on space mapping, \ve construc~a displacement function that irmxpolatcs values t)f the defining function in given control points. "I"henan algebraic sum (difference) of [he defining function and [hc displactmcnt function describes the deformed solid. B]obby dcforrna[ion, dcformaliort with a volurnc splint, and deformation con[rollcd by a parametric curve arc (fiscusscd. f310bby deformation mmfcls pinching and pricking that resull in small bUtnpS, '1'() define rnorc! global dcforma[iorr we usc the volurnc spl[nc lurrctmn dcrlvcd forscattcrccf points and possessing minimal energy propcrt!. "[lis approach has been applied [o reconstruct solids from given surface points. Conlml (If dcformatiorr wilh a p:ir~mctric curve all(}vs (() produce sweep-llkc shapes placed on inltlai surlaccs.
2013 International Conference on Cyberworlds, 2013
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Papers by Vladimir Savchenko