Browsing by Subject "Animation"

Now showing 1 - 20 of 36

Open Access
3D Hair sketching for real-time dynamic & key frame animations
(Springer, 2008-07) Aras, R.; Başarankut, B.; Çapın, T.; Özgüç, B.
Physically based simulation of human hair is a well studied and well known problem. But the "pure" physically based representation of hair (and other animation elements) is not the only concern of the animators, who want to "control" the creation and animation phases of the content. This paper describes a sketch-based tool, with which a user can both create hair models with different styling parameters and produce animations of these created hair models using physically and key frame-based techniques. The model creation and animation production tasks are all performed with direct manipulation techniques in real-time. © 2008 Springer-Verlag.
Open Access
Animated mesh simplification based on saliency metrics
(2008) Tolgay, Ahmet
Mesh saliency identifies the visually important parts of a mesh. Mesh simplification algorithms using mesh saliency as simplification criterion preserve the salient features of a static 3D model. In this thesis, we propose a saliency measure that will be used to simplify animated 3D models. This saliency measure uses the acceleration and deceleration information about a dynamic 3D mesh in addition to the saliency information for static meshes. This provides the preservation of sharp features and visually important cues during animation. Since oscillating motions are also important in determining saliency, we propose a technique to detect oscillating motions and incorporate it into the saliency based animated model simplification algorithm. The proposed technique is experimented on animated models making oscillating motions and promising visual results are obtained.
Open Access
Animation of boiling phenomena
(IEEE, 2008-05) Bülbül, Abdullah; Küçüktunç, Onur; Özgüç, Bülent
Phenomenon of boiling is a challenging topic for computer graphics due to its complex hydrodynamics and formulation. Realistic fluid animations require very heavy three-dimensional fluid flow calculations, and surface estimations as well. However, realism and performance are the two important objectives of the boiling animation for a real-time application. We present an efficient method for the simulation of boiling water in this paper. The method is based on modeling the bubbles and waves as particles. Grid-based approach is used both for the heating and the fluid surface. Our technique makes it possible to produce the animation of boiling phenomena nearly in real-time. ©2008 IEEE.
Open Access
Animation of deformable models
(Pergamon Press, 1994) Güdükbay, Uğur; Özgüç, B.
Although kinematic modelling methods are adequate for describing the shapes of static objects, they are insufficient when it comes to producing realistic animation. Physically based modelling remedies this problem by including forces, masses, strain energies and other physical quantities. The paper describes a system for the animation of deformable models. The system uses physically based modelling methods and approaches from elasticity theory for animating the models. Two different formulations, namely the primal formulation and the hybrid formulation, are implemented so that the user can select the one most suitable for an animation depending on the rigidity of the models. Collision of the models with impenetrable obstacles and constraining of the model points to fixed positions in space are implemented for use in the animations. © 1994.
Open Access
An animation system for fracturing of rigid objects
(Springer, Berlin, Heidelberg, 2005) Küçükyilmaz, Ayşe; Özgüç, Bülent
This paper describes a system for the animation of fracturing brittle objects. The system combines rigid body simulation methods with a constraint-based model to animate fracturing of arbitrary polyhedral shaped objects under impact. The objects are represented as sets of masses, where pairs of adjacent masses are connected via a distance-preserving linear constraint. Lagrange multipliers are used to compute the forces exerted by those constraints, where these forces determine how and where the object will break. However, a problem with existing systems is that the initial body models exhibit well-defined uniformity, which makes the generated animations unrealistic. This work introduces a method for generating more realistic cracks without any performance loss. This method is easy to implement and applicable on different models. © Springer-Verlag Berlin Heidelberg 2005.
Open Access
Animator's hell : an animation inspired by Sartre's other
(2012) Akgülgil, Nadide Gizem
Animation is a form that allows the animator to enter a world of impossibilities. Things that are hard or impossible to show in live action become easier or possible in animation. The animator as a subject animates an object that has no life, soul and movement. So the whole relationship is between the subject and object. French philosopher Sartre, on the other hand, plays with the concepts of subject and object when he constructs his philosophy on existence especially in Other concept. When a man confronts with another one, he puts the other in an object form in his world. As the one does so, the other also does the same, i.e. puts the other in an object form. When they confront and become objects for the other’s world they start judging each other. The Other, for this reason, is hell, according to Sartre. Animator’s Hell is a clay animation, which attempts to integrate Jean Paul Sartre’s concepts of subject - object relations and the Other into animation. It tells the story of an animator who defines an object for her animation but later faces with the fact that it is actually a subject. The characters in the film become hell for each other, and try to be recognized.
Open Access
Combined filtering and key-frame reduction of motion capture data with application to 3DTV
(WSCG, 2006-01-02) Önder, Onur; Erdem, Ç.; Erdem, T.; Güdükbay, Uğur; Özgüç, Bülent
A new method for combined filtering and key-frame reduction of motion capture data is proposed. Filtering of motion capture data is necessary to eliminate any jitter introduced by a motion capture system. Key-frame reduction, on the other hand, allows animators to easily edit motion data by representing animation curves with a significantly smaller number of key frames. The proposed technique achieves key frame reduction and jitter removal simultaneously by fitting a Hermite curve to motion capture data using dynamic programming. Copyright © UNION Agency - Science Press.
Open Access
Creating crowd variation with the OCEAN personality model
(IFAAMAS, 2008-05) Durupınar, Funda; Allbeck, J.; Pelechano, N.; Badler, N.
Most current crowd simulators animate homogeneous crowds, but include underlying parameters that can be tuned to create variations within the crowd. These parameters, however, are specific to the crowd models and may be difficult for an animator or naive user to use. We propose mapping these parameters to personality traits. In this paper, we extend the HiDAC (High-Density Autonomous Crowds) system by providing each agent with a personality model in order to examine how the emergent behavior of the crowd is affected. We use the OCEAN personality model as a basis for agent psychology. To each personality trait we associate nominal behaviors; thus, specifying personality for an agent leads to an automation of the low-level parameter tuning process. We describe a plausible mapping from personality traits to existing behavior types and analyze the overall emergent crowd behaviors. Copyright © 2008, International Foundation for Autonomous Agents and Multiagent Systems (www.ifaamas.org). All rights reserved.
Open Access
A decision theoretic approach to motion saliency in computer animations
(Springer, Berlin, Heidelberg, 2011) Arpa, Sami; Bülbül, Abdullah; Çapın, Tolga
We describe a model to calculate saliency of objects due to their motions. In a decision-theoretic fashion, perceptually significant objects inside a scene are detected. The work is based on psychological studies and findings on motion perception. By considering motion cues and attributes, we define six motion states. For each object in a scene, an individual saliency value is calculated considering its current motion state and the inhibition of return principle. Furthermore, a global saliency value is considered for each object by covering their relationships with each other and equivalence of their saliency value. The position of the object with highest attention value is predicted as a possible gaze point for each frame in the animation. We conducted several eye-tracking experiments to practically observe the motion-attention related principles in psychology literature. We also performed some final user studies to evaluate our model and its effectiveness. © 2011 Springer-Verlag.
Open Access
An ecofeminist approach on Turkish and American animations
(2022-05) Dündar, Irmak
This thesis aims to analyze and compare four Turkish and four American animations from an ecofeminist perspective. The selected animations from Turkey are Kral Şakir Cumburlop (2021), Pırıl (2019-), Rafadan Tayfa 2: Göbeklitepe (2019), Kötü Kedi Şerafettin (2016) while the animations from the US are Frozen (2013), Avatar: The Last Airbender (2005-2008), She-Ra and the Princesses of Power (2018-2020), Invincible (2021-). Each selected animation is given an age range for the purposes of this research and these ranges indicate which animation pair is compared in terms of ecofeminism concepts. Close reading method is conducted to each animated work with the help of the Bechdel Test as well as the Maisy Test. Regardless of its location or which platform it gets aired, animations have been an important part of people’s entertainment. A concept as relevant and needed as ecofeminism should be researched within animation and its’ related concepts in order to show animation audiences the feminist and ecologically positive world views.
Open Access
Emergency crowd simulation for outdoor environments
(Pergamon Press, 2010) Oğuz, O.; Akaydın, A.; Yilmaz, T.; Güdükbay, Uğur
We simulate virtual crowds in emergency situations caused by an incident, such as a fire, an explosion, or a terrorist attack. We use a continuum dynamics-based approach to simulate the escaping crowd, which produces more efficient simulations than the agent-based approaches. Only the close proximity of the incident region, which includes the crowd affected by the incident, is simulated. We use a model-based rendering approach where a polygonal mesh is rendered for each agent according to the agent's skeletal motion. To speed up the animation and visualization, we employ an offline occlusion culling technique. We animate and render a pedestrian model only if it is visible according to the static visibility information computed. In the pre-processing stage, the navigable area is decomposed into a grid of cells and the from-region visibility of these cells is computed with the help of hardware occlusion queries. © 2009 Elsevier Ltd. All rights reserved.
Open Access
Example based retargeting human motion to arbitrary mesh models
(2013) Yaz, İlker O.
Animation of mesh models can be accomplished in many ways, including character animation with skinned skeletons, deformable models, or physic-based simulation. Generating animations with all of these techniques is time consuming and laborious for novice users; however adapting already available wide-range human motion capture data might simplify the process signi cantly. This thesis presents a method for retargeting human motion to arbitrary 3D mesh models with as little user interaction as possible. Traditional motion retargeting systems try to preserve original motion as is, while satisfying several motion constraints. In our approach, we use a few pose-to-pose examples provided by the user to extract desired semantics behind retargeting process by not limiting the transfer to be only literal. Hence, mesh models, which have di erent structures and/or motion semantics from humanoid skeleton, become possible targets. Also considering mesh models which are widely available and without any additional structure (e.g. skeleton), our method does not require such a structure by providing a build-in surface-based deformation system. Since deformation for animation purpose can require more than rigid behaviour, we augment existing rigid deformation approaches to provide volume preserving and cartoon-like deformation. For demonstrating results of our approach, we retarget several motion capture data to three well-known models, and also investigate how automatic retargeting methods developed considering humanoid models work on our models.
Open Access
Example-based retargeting of human motion to arbitrary mesh models
(Blackwell Publishing Ltd, 2015) Celikcan, U.; Yaz I.O.; Capin, T.
We present a novel method for retargeting human motion to arbitrary 3D mesh models with as little user interaction as possible. Traditional motion-retargeting systems try to preserve the original motion, while satisfying several motion constraints. Our method uses a few pose-to-pose examples provided by the user to extract the desired semantics behind the retargeting process while not limiting the transfer to being only literal. Thus, mesh models with different structures and/or motion semantics from humanoid skeletons become possible targets. Also considering the fact that most publicly available mesh models lack additional structure (e.g. skeleton), our method dispenses with the need for such a structure by means of a built-in surface-based deformation system. As deformation for animation purposes may require non-rigid behaviour, we augment existing rigid deformation approaches to provide volume-preserving and squash-and-stretch deformations. We demonstrate our approach on well-known mesh models along with several publicly available motion-capture sequences. We present a novel method for retargeting human motion to arbitrary 3D mesh models with as little user interaction as possible. Traditional motion-retargeting systems try to preserve the original motion, while satisfying several motion constraints. Our method uses a few pose-to-pose examples provided by the user to extract the desired semantics behind the retargeting process while not limiting the transfer to being only literal. Thus, mesh models with different structures and/or motion semantics from humanoid skeletons become possible targets. © 2014 The Eurographics Association and John Wiley & Sons Ltd.
Open Access
Keyframe reduction techniques for motion capture data
(IEEE, 2008-05) Önder, Onur; Güdükbay, Uğur; Özgüç, Bülent; Erdem, T.; Erdem, Ç.; Özkan, M.
Two methods for keyframe reduction of motion capture data are presented. Keyframe reduction of motion capture data enables animators to easily edit motion data with smaller number of keyframes. One of the approaches achieves keyframe reduction and noise removal simultaneously by fitting a curve to the motion information using dynamic programming. The other approach uses curve simplification algorithms on the motion capture data until a predefined threshold of number of keyframes is reached. Although the error rate varies with different motions, the results show that curve fitting with dynamic programming performs as good as curve simplification methods. ©2008 IEEE.
Restricted
Kubo ... And The Two Strings
(2016-01-05) Haimes, Marc; Butler, Chris; Tindle, Shannon; Haimes, Marc; Knight, Travis
Open Access
Mars: A tool-based modeling, animation, and parallel rendering system
(Springer, 1994) Aktıhanoğlu, M.; Özgüç, B.; Aykanat, Cevdet
This paper describes a system for modeling, animating, previewing and rendering articulated objects. The system has a modeler of objects that consists of joints and segments. The animator interactively positions the articulated object in its stick, control vertex, or rectangular prism representation and previews the motion in real time. Then the data representing the motion and the models is sent to a multicomputer [iPSC/2 Hypercube (Intel)]. The frames are rendered in parallel, exploiting the coherence between successive frames, thus cutting down the rendering time significantly. Our main aim is 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, an efficient rendering can be achieved. © 1994 Springer-Verlag.
Open Access
Media convergence in animation : an analysis of aesthetic uniformity
(2017-01) Gündeş, Feridun
This thesis analyzes the uniformity in animation aesthetics within the framework of convergence theory. The sources of aesthetic diversity in animation art are demonstrated along with the process though which these became precarious over time as realism became an end in itself. It is suggested that the diversity is due to the independent use of such elements of the screen image as the line and the form, and such elements related to movement as the motion and the time. When these elements are harnessed to create a realistic image and movement, the diversity is lost, and there occurs uniformity. This has been aggravated with the emerging computer technology which made it possible to create highly indexical photorealistic images and videorealistic movement. This process can be interpreted as a special case of digital and technological media convergence, which brought together previously separate design activities, and merged their aesthetic principles. The result is an hybrid aesthetics prevalent over separate domains, including animation. Due to industry related reasons, this realism based aesthetic approach became so dominant that it pushed all the others to obscurity, causing a decrease in diversity and increase in uniformity in animation aesthetics.
Open Access
Motion capture and human pose reconstruction from a single-view video sequence
(Academic Press, 2013) Güdükbay, Uğur; Demir, I.; Dedeoǧlu, Y.
We propose a framework to reconstruct the 3D pose of a human for animation from a sequence of single-view video frames. The framework for pose construction starts with background estimation and the performer's silhouette is extracted using image subtraction for each frame. Then the body silhouettes are automatically labeled using a model-based approach. Finally, the 3D pose is constructed from the labeled human silhouette by assuming orthographic projection. The proposed approach does not require camera calibration. It assumes that the input video has a static background, it has no significant perspective effects, and the performer is in an upright position. The proposed approach requires minimal user interaction. © 2013 Elsevier Inc.
Open Access
Motion capture from single video sequence
(2006) Demir, İbrahim
3D human pose reconstruction is a popular research area since it can be used in various applications. Currently most of the methods work for constrained environments, where multi camera views are available and camera calibration is known, or a single camera view is available, which requires intensive user effort. However most of the currently available data do not satisfy these constraints, thus they cannot be processed by these algorithms. In this thesis a framework is proposed to reconstruct 3D pose of a human for animation from a sequence of single view video frames. The framework for pose construction starts with background estimation. Once the image background is estimated, the body silhouette is extracted by using image subtraction for each frame. Then the body silhouettes are automatically labeled by using a model-based approach. Finally, the 3D pose is constructed from the labeled human silhouette by assuming orthographic projection. The proposed approach does not require camera calibration. The proposed framework assumes that the input video has a static background and it has no significant perspective effects and the performer is in upright position.
Open Access
Motion control for realistic walking behavior using inverse kinematics
(IEEE, 2007-05) Memişoǧlu, Aydemir; Güdükbay,Uğur; Özgüç, Bülent
This study presents an interactive hierarchical motion control system for the animation of human figure locomotion. The articulated figure animation system creates movements using motion control techniques at different levels, like goal-directed motion and walking. Inverse Kinematics using Analytical Methods (IKAN) software, developed at the University of Pennsylvania, is utilized for controlling the motion of the articulated body. © 2007 IEEE.