Wyniki wyszukiwania - BazTech

1

Branched iterated function system (IFS) models with positioners for biological visualizations

Stępień C., Prolejko M.

Bio-Algorithms and Med-Systems

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2015

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Vol. 11, no. 4

237--241

EN

While researching new algorithms for computer graphics, we focused on the ones that are useful in modeling biological formations. Iterated function systems (IFS) are commonly used to visualize fractals or 3D selfsimilar objects. Their main advantage is the brevity. In the simplest cases, it is enough to define the shape of the base module and the set of transformations to create a multimodular object. In the literature, models of shells, horns, and beaks are described. To model more complex formations, the modified method was introduced in which parameters of the transformation depend on the number of iteration. Methods: The presented method combines IFS with a new approach to modeling compound objects, which uses positioners. The positioner itself and its possible applications were described in papers that do not refer to IFS models. Results: We show here how to use positioners with IFS models, including branched ones (as models of the bronchial tree). The achieved models can be simplified or more accurate depending on the variant of the algorithm. Thanks to the positioners, these models have a continuous lateral surface regardless of used shape of cross-section. The algorithm is described along with the requirements for a base module. Conclusions: It is indicated that positioners simplify the work of a graphic designer. Obtained models of bronchial trees can be used (e.g. in 3D interactive visualizations for medicine students).

2

The use of positioners in creation modular models of horns for mammals from the Bovidae family

Stępień C., Prolejko M.

Mathematica Applicanda

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2014

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Vol. 42, No. 2

179--192

EN

The paper describes the method suitable for creating animated modular models of horns for mammals belonging to the Bovidae family. This method uses the time-dependent positioners. They are used in two ways: for placing modules appropriately to each other and for creating lateral surfaces of the modules. Thanks to double usage of the positioners, a continuous surface is achieved regardless of the complexity of the time-dependent parameters. There are considered different connections between parameters of modules, justified from the point of view of modeling the horns. The method is illustrated with the example of creation a time-dependent ram's horn model.

PL

W pracy opisano metodę tworzenia animowanych modułowych modeli rogów ssaków z rodziny krętorogich, w której wykorzystano pojęcie pozycjonerów. W metodzie wykorzystuje się zależne od czasu pozycjonery na dwa sposoby: do ustawiania modułów względem siebie oraz do tworzenia powierzchni bocznej modułu. Dzięki podwójnemu wykorzystaniu pozycjonerów uzyskujemy ciągłość powierzchni bocznej bryły złożonej, bez względu na stopień skomplikowania parametrów zależnych od czasu. Rozważa się różne powiązania parametrów poszczególnych modułów, uzasadnione z punktu widzenia modelowania rogów. Metodę zilustrowano przykładem tworzenia modelu rogu baraniego.

3

A method of constructing phyllotaxically arranged modular models by partitioning the interior of a cylinder or a cone

Stępień C.

Machine Graphics and Vision

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2014

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Vol. 23, No. 1/2

21--36

EN

The paper describes a method of partitioning a cylinder space into three-dimensional subspaces, congruent to each other, as well as partitioning a cone space into subspaces similar to each other. The way of partitioning is of such a nature that the intersection of any two subspaces is the empty set. Subspaces are arranged with regard to phyllotaxis. Phyllotaxis lets us distinguish privileged directions and observe parastichies trending these directions. The subspaces are created by sweeping a changing cross-section along a given path, which enables us to obtain not only simple shapes but also complicated ones. Having created these subspaces, we can put modules inside them, which do not need to be obligatorily congruent or similar. The method ensures that any module does not intersect another one. An example of plant model is given, consisting of modules phyllotaxically arranged inside a cylinder or a cone.

4

The method of animation of a growing spruce with seasonal model changes

Regiński M., Stępień C.

Machine Graphics and Vision

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1998

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Vol. 7, No. 1/2

15-26

EN

This paper describes an algorithm which generates a model of a tree in different moments of it's life. The algorithm, in opposition to those already known, enables to get the model in time period shorter than a year. Therefore it is possible to make an animation of growing tree including seasonal changes in its appearance. A morphing method was used as a base of this animation. Necessary transformations of a sequence of models are presented in order to adapt these models to the standard of the morphing methods.