<p>3D Models of botanical trees are very important in video games, simulation, virtual reality, digital city modeling and other fields of computer graphics. However, since the early days of computer graphics, the modeling of trees has been challenging, because of the huge dynamical range between its smallest and largest structures and their geometrical complexity. Trees are also ubiquitous which makes it even hard to model them in a realistic way, Current techniques are limited in that they model a tree either in a rule-based way or in an approximated way. These methods emphasize appearance while sacrificing its real structure. Recent development in range scanners are making 3D aquisition feasible for large and complex objects. This report presents the semi-automatic technique developed for modeling laser-scanned trees. First, the user draws a few strokes on the depth image plane generated from the dataset. Branches are then extracted through the 2D Curve detection algorithm originally developed. Afterwards, those short branches are connected together to generate the skeleton of the tree by forming a Minimum Spanning Tree (MST). Finally, the geometry of the tree skeleton is produced using allometric rules for branch thickness and branching angles.</p>

3D Models of botanical trees are very important in video games, simulation, virtual reality, digital city modeling and other fields of computer graphics. However, since the early days of computer graphics, the modeling of trees has been challenging, because of the huge dynamical range between its smallest and largest structures and their geometrical complexity. Trees are also ubiquitous which makes it even hard to model them in a realistic way, Current techniques are limited in that they model a tree either in a rule-based way or in an approximated way. These methods emphasize appearance while sacrificing its real structure. Recent development in range scanners are making 3D aquisition feasible for large and complex objects. This report presents the semi-automatic technique developed for modeling laser-scanned trees. First, the user draws a few strokes on the depth image plane generated from the dataset. Branches are then extracted through the 2D Curve detection algorithm originally developed. Afterwards, those short branches are connected together to generate the skeleton of the tree by forming a Minimum Spanning Tree (MST). Finally, the geometry of the tree skeleton is produced using allometric rules for branch thickness and branching angles.

This thesis deals with rotation estimation of 3D model of human jaw. It describes and compares methods for direct analysis od 3D models as well as method to analyze model using rasterization. To evaluate perfomance of proposed method, a metric that computes number of cases when prediction was less than 30° from ground truth is used. Proposed method that uses rasterization, takes  three x-ray views of model as an input and processes it with convolutional network. It achieves best preformance, 99% with described metric. Method to directly analyze polygonal model as a sequence uses attention mechanism to do so and was inspired by transformer architecture. A special pooling function was proposed for this network that decreases memory requirements of the network. This method achieves 88%, but does not use rasterization and can process polygonal model directly. It is not as good as rasterization method with x-ray display, byt it is better than rasterization method with model not rendered as x-ray.  The last method uses graph representation of mesh. Graph network had problems with overfitting, that is why it did not get good results and I think this method is not very suitable for analyzing plygonal model.

This project is engaged in optimalization of 3D polygonal models. Main automatic and also manual principles and methods used in the area of character model optimalization are introduced and discussed. Next the approach named geometry mapping, which was created as a part of the project and enables the creation of models with desired topology, is described.

[pt] A tese apresenta o modelo poligonal, um paradigma autoral criado para a análise de canções populares centrado no peso de quatro parâmetros: melodia, contabilidade, forma e sentido. Traduções de canções podem ser avaliadas usando os mesmos quesitos, o que permite uma visualização rápida dos erros e acertos do tradutor. O modelo é colocado à prova com a análise e tradução autoral (e comentada) de três canções: Highway 61 Revisited e All Along the Watchtower, de Bob Dylan, e Idioteque, do Radiohead. Uma semelhança influenciou a escolha desses dois artistas: eles têm fases musicais muito bem definidas: Dylan começou a carreira como músico folk tocando instrumentos acústicos e acabou adotando instrumentos elétricos; já o Radiohead tinha um som rock n roll e lançou álbuns com uma influência mais eletrônica. Então, para pensar na questão da performance e nas influências artísticas de cada canção, as três traduções foram gravadas. / [en] This dissertation introduces the polygonal model, a paradigm for the analysis of translation of popular music centered around four parameters: melody, singability, form, and sense. Translations of songs can be evaluated with the same criteria, which allows for a quick way to visualize the translator s mistakes and successes. The model is tested with the analyses of commented translations of three songs: Highway 61 Revisited and All Along the Watchtower, written by Bob Dylan, and Idioteque, written by Radiohead. A similarity influenced why those two artists were chosen: Dylan started out as a folk musician playing acoustic instruments and then went electric; Radiohead had a rock n roll sound, but then released albums with a heavy electronic influence. In order to think about performance and the artistic influences from each song, the three translations were recorded.

This thesis deals with the concept of virtual reality, its history, present-day possibilities and available devices and technologies for virtual reality and ways of creating assets such as models, textures and animations for virtual reality applications. The practical part of this work deals with design and creation of three-dimensional models, textures, animations and environment for use in interactive application in virtual reality and also with design and creation of such application to demonstrate their use.