Wyniki wyszukiwania - BazTech

1

Procedural Modelling of Three-Dimensional Geometry

Zawadzki T., Nikiel S., Warszawski K.

Machine Graphics and Vision

|

2011

|

Vol. 20, No. 2

113-138

EN

Modelling three-dimensional shapes plays an increasingly significant role in modern computer graphics. Geometry synthesis is used in many fields, including digital cinema, electronic entertainment and computer simulations. Unfortunately, the modelling process is still done manually, offering a unique output at the cost of tedious work. There is a constant need to replace designers' work with intelligent automated algorithms. The methods based on the automation of modelling processes offer a variety of three-dimensional structures within limited time and restricted money budget. This paper addresses the problem of automated modelling of virtual structures such as caves, buildings and clouds, and presents an alternative solution in the form of a hybrid system. The innovative approach combines two independent methods well known in three-dimensional computer graphics: shape grammar and shape morphing. In the modelling process, it is possible to obtain the characteristics of 3D structures with non-spherical mesh topology. The objects and their transformations are described by functions, while rule grammars define the geometry modelling process. The shapes thus obtained can be freely deformed in the subsequent rules. The resulting structure can be rendered up to very high levels of visual realism. However, in the paper we present the description of the algorithm illustrated by results on a 3D mesh without focusing on photorealistic rendering aspects. We also propose some measures that can be used to verify the model geometry.

2

Zastosowanie strumienia cząstek w modelowaniu wirtualnych struktur erozyjnych

Warszawski K.

Metody Informatyki Stosowanej

|

2010

|

nr 1 (22)

195-200

EN

Automated techniques of landscape modeling is an important part of environments in Virtual Reality systems. A method is proposed that applies particle systems to modify height-field based landscapes with erosion process. Construction of particle systems is discussed, along with its main attributes and influence on the final product of the modeling process. The key data structure for the modeled landscape is a typical height-field and hardness map, both are based on a two dimensional arrays. Each cell of height-field represents the altitude at a coordination point defined by rows and columns of this array and cells in hardness map represents this point susceptibility for erosion process. This kind of data structures enables fast and simple implementation of terrain deformation and erosion. The proposed method is not intended to simulate a physical erosion process but it focuses on its results for exploitation in virtual environments in real-time visualizations.

3

Wstęp do komputerowego generowania koryta rzeki z wykorzystaniem systemu cząstek na potrzeby modelowania wirtualnego środowiska

Warszawski K., Zawadzki T.

Pomiary Automatyka Kontrola

|

2009

|

R. 55, nr 7

464-466

PL

Artykuł przybliża idee zastosowania systemu cząstek do automatycznego deformowania struktur terenowych. Za pomocą proponowanej metody można od podstaw ukształtować krajobraz jak i można jej użyć do deformacji wstępnie predefiniowanego ukształtowania terenu i wzbogacenia jego powierzchni o struktury przypominające formacje powstałe na skutek długotrwałego oddziaływania erozji hydrologicznej, tj. kanion czy koryto rzeki. Ze względu na krótki czas pracy algorytmu, który zbliżony jest do rzeczywistego, metoda pozwala na uzyskanie w rozsądnym czasie wybranych struktur terenowych również na typowych komputerach osobistych.

EN

The paper deals with a method that applies the particle system to modify height-field based landscapes with generation of hydrological erosion like canyons or riverbeds. The authors present a construction of the particle system, its main attributes and its influence on the final product of the modelling process. Performance of the particle-based algorithm is close to real-time, thus it offers the opportunity for fast terrain surface modifications, which enable selected landscapes to be rendered in real-time on typical desktop computers [6, 7]. The main data structure of the modelled terrain is typical height-field, based on a two dimensional array. Each cell represents the altitude at a coordination point defined by rows and columns of this array. This kind of landscape data structure enables fast and simple implementation of the terrain deformation and can be rendered in any virtual reality systems. In the paper there are discussed the basic problems of landscape hydrological erosion deformations and there is proposed a fast alternative to the algorithms based on Computational Fluids Dynamic (CFD) or rainfall erosion [9, 11]. The proposed method is not intended to simulate physically the erosion process but to focus on its results for exploitation in virtual environments in on-line visualisations.

4

Modelowanie środowisk wirtualnych w X3D

Zawadzki T., Warszawski K.

Pomiary Automatyka Kontrola

|

2009

|

R. 55, nr 7

467-469

PL

Artykuł dotyczy tematu tworzenia nieistniejących już w rzeczywistości obszarów miejskich przy wykorzystaniu rozszerzalnego języka modelowania wirtualnej rzeczywistości (X3D). Omówione zostaną techniki optymalizacji oraz modelowania obiektów 3D w kontekście wymagań sprzętowych. Poruszony zostanie aspekt tworzenia sceny z uwzględnieniem jej realizmu: sposoby nadawania obiektom możliwości interakcji z użytkownikiem, kolizje obiektów, oświetlenie sceny, animacja ruchu roślin, drzew oraz nieba. Opisane zostaną techniki generowania dźwięku za pomocą sensorów, które pozwalają na stworzenie narracji w scenie. Efektem finalnym będzie przedstawienie wizualizacji dawnego miasta Zielonej Góry połączonej z możliwością nawigacji w czasie rzeczywistym.

EN

The paper deals with reconstruction of non-existing city landscapes with use of an extended language of modelling virtual reality X3D (Extensible 3D). There are discussed some problems of technical optimisation and modelling of 3D objects in context of system recommendations. The aspects of creating scenes including realism: ways of giving objects ability to interact with the user, object collisions, lighting and shadows, movement of plants, trees and the sky are considered as well. The problem described is illustrated by visualization of Zielona Góra old town, which enables the user to explore and move through virtual scenes in real-time. The information on the old town was received from the XVIII century model of Zielona Góra exhibited at the Museum of Zielona Góra [5]. Another information on monuments was found in historical books of Zielona Góra old town [2, 3, 4]. Application of many techniques of optimisation improved the efficiency of displaying the world. At the beginning of construction of virtual models it was important not to use excessive polygons. Another optimisation technique was to create optimal models using node LOD (Level of Detail) that helped to improve efficiency rendering and not to loose realism of the presented virtual objects (Fig. 2). One of important stages of the project was to give objects the ability of interaction with the user. The project was created by means of the hybrid technique that joins a manual technique which is implementation of the code X3D language to a notepad and a program technique which uses existing tools (Cinema_4D, Avatar Studio). The Viewpoint nodes help to create better navigation, which improves the process of exploration of a virtual town (Fig. 4). Creating virtual reality environments based on architectural visualization is a very hard and time-consuming task because the structure of these objects is complex and the system limits must be taken into consideration. The aim of the work was reached. The final application is a reconstruction of Zielona Góra old town that lets the user to explore and move throughout the virtual scenes (Fig. 5).

5

Automatyczna regulacja procesu wzbogacania węgla w cieczach ciężkich w zakładzie przeróbki węgla kopalni "Zofiówka"

Cierpisz St., Warszawski K.

Przegląd Górniczy

|

1999

|

T. 55, nr 2

12-15

PL

Przedstawiono układ automatycznej regulacji obiegów cieczy ciężkiej zainstalowany i uruchomiony w 1997 r. w kopalni "Zofiówka". W układzie tym zastosowano nowe urządzenia pomiarowe, elementy wykonawcze i rozszerzony algorytm sterowania w stosunku do dotychczas eksploatowanych w innych kopalniach podobnych układów. Omówiono doświadczenia ze wstępnej eksploatacji układu sterowania.

EN

The dense medium circuits automatic control system installed and put into operation in 1997 at "Zofiówka" Colliery is presented. New measuring arrangements, executive elements and an extended control algorithm in comparison with so far operated in the other mines have been applied in this system. The initial system operation experience is discussed.