Browsing by Subject "Rendering"

Now showing 1 - 7 of 7

Open Access
MARS: a tool-based modeling, animation and parallel rendering system
(1992) Aktıhanoğlu, Murat
A b stract: This thesis describes a system for modeling, animating, previewing and rendering articulated objects. Tl^^ system has a modeler which models objects, consisting of joints and segments. The animatoi- interactively positions the articulated object in its stick, control vertex or rectangular prism representation into the keyframes, interpolates inbetweens and previews the motion in real time. Then the data representing the motion and the models is sent to a multicomputer {iPSC/2 Ilypercube^). The frames are rendered in parallel by distributed processing techniques, exploiting the coherence between successive frames, thus cutting down the rendering time significantly. The main aim of this research has been to make a detailed study on rendering of a sequence of 3D scenes. The results show that due to an inherent correlation between the 3D scenes, a much more efficient rendering than the conventional sequential one can be done.
Open Access
Modeling and animating personalized faces
(2002) Erol, Fatih
A very important and challenging problem in computer graphics is modeling and animation of individualized face models. In this thesis, we describe a facial modeling and animation system attempting to address this problem. The system uses muscle-based generic face model and deforms it using deformation techniques to model individualized faces. Two orthogonal photos of the real faces are used for this purpose. Image processing techniques are employed to extract certain features on the photographs, which are then refined manually by the user through the facilities of the user interface of the system. The feature points located on the frontal and side views of a real face are used to deform the generic model. Then, the muscle vectors in the individualized face model are arranged accordingly. Individualized face models produced in this manner are animated using parametric interpolation techniques.
Open Access
Real-time fur modeling with simulation of physical effects
(2012) Arıyürek, Sinan
Fur is one of the important visual aspects of animals and it is quite challenging to model it in computer graphics. This is due to rendering and animating high amounts of geometry taking excessive time in our personal computers. Thus in computer games most of the animals are without fur or covered with a single layer of texture. But these current methods do not provide the reality and even if the rendering in the game is realistic the fur is omitted. There have been several models to render a fur, but the methods that incorporate rendering are not in real-time, on the other hand most of the real-time methods omit many of the natural aspects , such as; texture lighting, shadow and animation. Thus the outcome is not sufficient for realistic gaming experience. In this thesis we propose a real-time fur represantation that can be used on 3D objects. Moreover, we demonstrate how to; render, animate and burn this real-time fur.
Open Access
Realistic rendering and animation of a multi-layered human body model
(IEEE, 2006) Yeşil, Mehmet Şahin; Güdükbay, Uğur
A framework for realistic rendering of a multi-layered human body model is proposed in this paper. The human model is composed of three layers: skeleton, muscle, and skin. The skeleton layer, represented by a set of joints and bones, controls the animation of the human body using inverse kinematics. Muscles are represented with action lines that are defined by a set of control points. An action line applies the force produced by a muscle on the bones and on the skin mesh. The skin layer is modeled as a 3D mesh and deformed during animation by binding the skin layer to both the skeleton and muscle layers. The skin is deformed by a two-step algorithm according to the current state of the skeleton and muscle layers. Performance experiments show that it is possible to obtain real-time frame rates for a moderately complex human model containing approximately 33,000 triangles on the skin layer. © 2006 IEEE.
Open Access
Scene representation technologies for 3DTV-a survey
(Institute of Electrical and Electronics Engineers, 2007-11) Alatan, A. A.; Yemez, Y.; Güdükbay, Uğur; Zabulis, X.; Müller, K.; Erdem, C.; Weigel, C.; Smolic, A.
3-D scene representation is utilized during scene extraction, modeling, transmission and display stages of a 3DTV framework. To this end, different representation technologies are proposed to fulfill the requirements of 3DTV paradigm. Dense point-based methods are appropriate for free-view 3DTV applications, since they can generate novel views easily. As surface representations, polygonal meshes are quite popular due to their generality and current hardware support. Unfortunately, there is no inherent smoothness in their description and the resulting renderings may contain unrealistic artifacts. NURBS surfaces have embedded smoothness and efficient tools for editing and animation, but they are more suitable for synthetic content. Smooth subdivision surfaces, which offer a good compromise between polygonal meshes and NURBS surfaces, require sophisticated geometry modeling tools and are usually difficult to obtain. One recent trend in surface representation is point-based modeling which can meet most of the requirements of 3DTV, however the relevant state-of-the-art is not yet mature enough. On the other hand, volumetric representations encapsulate neighborhood information that is useful for the reconstruction of surfaces with their parallel implementations for multiview stereo algorithms. Apart from the representation of 3-D structure by different primitives, texturing of scenes is also essential for a realistic scene rendering. Image-based rendering techniques directly render novel views of a scene from the acquired images, since they do not require any explicit geometry or texture representation. 3-D human face and body modeling facilitate the realistic animation and rendering of human figures that is quite crucial for 3DTV that might demand real-time animation of human bodies. Physically based modeling and animation techniques produce impressive results, thus have potential for use in a 3DTV framework for modeling and animating dynamic scenes. As a concluding remark, it can be argued that 3-D scene and texture representation techniques are mature enough to serve and fulfill the requirements of 3-D extraction, transmission and display sides in a 3DTV scenario. © 2007 IEEE.
Open Access
A tool for generating three dimensional animation on computers
(1991) Türün, Cemil Şinasi
In this work, a three dimensional computer animation system has been designed to be employed in schools, for the training of art students on basic three dimensional animation techniques. Puppet Theater, as we have called the system, utilizes the flexibility and effectiveness of the low-end hardware, namely IBM PC™ computers supported with Targa 16™ graphics board and gives special emphasis to user friendliness. It Is basically a software to design three dimensional objects and choreograph the object data in the computer's memory, before rendering the resulting scenery with shading methods. The system is the result of reflecting the recent advances in the field of computer graphics and pushing the potentials of the existing platform. Software is Implemented in C language, thus the code is transportable. A custom designed object oriented windowing system called WODNTW is used as the user Interface. This open windowing system supports pull-down menus, interactive buttons, scalable windows and other popular user interface elements.
Open Access
Walkthrough in complex environments at interactive rates using level-of-detail
(TÜBİTAK, 2002) Selçuk, Alper; Güdükbay, Uğur; Özgüç, Bülent
One of the biggest problems in computer graphics is displaying huge geometric models at interactive rates. A lot of work has been done to achieve the required frame-rates in architecture, simulation, computer-aided design and entertainment applications. In this paper, a system that enables walkthrough in complex environments using level-of-detail approximations is explained. The system uses hierarchical triangulated models as input. In the preprocessing phase, multiresolution models of objects are created using polygonal simplification techniques. During walkthrough, fast frustum culling based on bounding boxes is performed to eliminate branches of hierarchy that are not visible. An appropriate level for detail of objects is selected and displayed depending on the distance of the objects to the camera. For far nodes in the hierarchy, geometric data in lower levels is ignored and textured bounding boxes are displayed. The system achieves interactive frame rates for moderately complex models containing up to a million polygons.