Realistic Animation Research Articles

Twelve-month-old infants learn crossmodal associations between visual objects and natural sounds in ecologically valid situations

Infants are able to learn novel associations between visual objects and auditory linguistic labels (such as a dog and the sound /dɔg/) by the end of their first year of life. Surprisingly, at this age they seem to fail to learn the associations between visual objects and natural sounds (such as a dog and its barking sound). Researchers have therefore suggested that linguistic learning is special (Fulkerson and Waxman, 2007) or that unfamiliar sounds overshadow visual object processing (Robinson and Sloutsky, 2010). However, in previous studies visual stimuli were paired with arbitrary sounds in contexts lacking ecological validity. In the present study, we create animations of two novel animals and two realistic animal calls to construct two audiovisual stimuli. In the training phase, each animal was presented in motions that mimicked animal behaviour in real life: in a short movie, the animal ran (or jumped) from the periphery to the center of the monitor, and it made calls while raising its head. In the test phase, static images of both animals were presented side-by-side and the sound for one of the animals was played. Infant looking times to each stimulus were recorded with an eye tracker. We found that following the sound, 12-month-old infants preferentially looked at the animal corresponding to the sound. These results show that 12-month-old infants are able to learn novel associations between visual objects and natural sounds in an ecologically valid situation, thereby challenging our current understanding of the development of crossmodal association learning.

The Spontaneously Hypertensive Streptozotocin-induced Diabetic Rat – A More Realistic Animal Model than Hypertension and Diabetes in Isolation?

It is well established that SHR/STZ animals are suitable animal models for cardiometabolic disorders and are often utilised in studies requiring a more rapid onset of the pathological cascade. This study sought to compare the presentation and magnitude of cardiovascular dysfunction in adolescent SHR, STZ and SHR/STZ rats. Animals were incorporated into the study at eight weeks of age and diabetes was induced via a single intravenous dose of streptozotocin. All terminal assessments were conducted when animals were sixteen weeks of age.

Data-Driven Synthesis of Spatially Inflected Verbs for American Sign Language Animation

We are studying techniques for producing realistic and understandable animations of American Sign Language (ASL); such animations have accessibility benefits for signers with lower levels of written language literacy. This article describes and evaluates a novel method for modeling and synthesizing ASL animations based on samples of ASL signs collected from native signers. We apply this technique to ASL inflecting verbs, common signs in which the location and orientation of the hands is influenced by the arrangement of locations in 3D space that represent entities under discussion. We train mathematical models of hand movement on animation data of signs produced by a native signer. In evaluation studies with native ASL signers, the verb animations synthesized from our model had similar subjective-rating and comprehension-question scores to animations produced by a human animator; they also achieved higher scores than baseline animations. Further, we examine a split modeling technique for accommodating certain verb signs with complex movement patterns, and we conduct an analysis of how robust our modeling techniques are to reductions in the size of their training data. The modeling techniques in this article are applicable to other types of ASL signs and to other sign languages used internationally. Our models’ parameterization of sign animations can increase the repertoire of generation systems and can partially automate the work of humans using sign language scripting systems.

Evaluation of Three Animal Models for Concussion and Serious Brain Injury

Three animal models were evaluated in this study involving head impacts of the rat, including the Marmarou drop-weight and two momentum-exchange techniques. In series 1, 36 Wistar rats were hit on the side of the free-moving head using Marmarou's 450 g impact mass at 4.4, 5.4, and 6.3 m/s. Head acceleration was measured and injuries were observed. The 6.3-m/s side impact resulted in no deaths, no skull fractures, infrequent contusions, and some injuries consistent with diffuse axonal injury. In series 2, 57 Marmarou drop-weight tests were conducted to study head biomechanical responses. Marmarou's technique involves a head impact followed by prolonged loading into a foam pad under the animal. Based on the literature, the 2 m (6.3 m/s) Marmarou drop causes death, skull fracture, brain and spinal cord contusions, and diffuse axonal injury. These injuries are more severe than that occurring with impact of similar mass and velocity to the free-moving head. Impacts to the free-moving head provide more realistic animal models to study concussion and severe brain injury.

Retaining intradiscal pressure after annulotomy by different annular suture techniques, and their biomechanical evaluations

BackgroundThe adverse effects of annulotomy during lumbar discectomy have been increasingly recognized, and methods are developing to repair the annular defect. Biomechanically, the repair should retain the intra-nuclear pressure, which is doubtful using the current suture techniques. Therefore, a new suture technique was designed and tested to close a simpler type of annular incision. MethodsA new suture technique, the modified purse-string suture, was introduced into a re-validated nonlinear finite element human disk model after creating a standard transverse slit incision, as well as two other suture techniques: either two simple sutures, or a horizontal crossed suture, and compared their contact pressure on the cleft contact surface. Then, porcine lumbar endplate–disk–endplate complexes with transverse slit incisions were repaired using the three techniques. Quantitative discomanometry was then applied to compare their leakage pressure, as a parameter of disk integrity. FindingsIn finite element model, the new technique created the greatest contact pressure along the suture range (the outer annulus), and generated a minimum contact pressure at the critical point, which was 68% and 55% higher than the other two suture techniques. In quantitative discomanometry, the new suture technique also had an average leakage pressure of 85% and 49% higher than the other two suture techniques. InterpretationThe modified purse-string suture can generate higher contact pressure than the other two techniques at finite element analysis and in realistic animal models, which aids in retaining intra-discal pressure, and should be encouraged in clinical practice.

가상 수술 의료 시뮬레이션을 위한 소작 효과 애니메이션 기법

Practice education using virtual medical simulation has been recently introduced to maximize the learning efficiency in clinical environment. Specially, in minimally invasive surgery, the necessity of virtual surgery medical simulation has been substantially increased. Since cauterizing effect occurred frequently in minimally invasive surgery has been represented by simple bleeding, realistic cauterizing effect animation has not been proposed yet. In this paper, we propose realistic real-time cauterizing effect animation. Proposed method changes the individual element of each vertex color of the mesh and uses sigmoid function to impose weights for the smooth color change inside the valid mesh region so that the results of cauterizing effect animation was realistic. In addition, by proposing cauterizing color buffer, overlapped cauterizing effects can be realistically represented. Proposed method greatly improves the sense of the real and absorption in virtual surgery medical simulation so that the education efficiency of doctors and students using medical simulation can be maximized.

Weighted pose space editing for facial animation

Blendshapes are the most commonly used approach to realistic facial animation in production. A blendshape model typically begins with a relatively small number of blendshape targets reflecting major muscles or expressions. However, the majority of the effort in constructing a production quality model occurs in the subsequent addition of targets needed to reproduce various subtle expressions and correct for the effects of various shapes in combination. To make this subsequent modeling process much more efficient, we present a novel editing method that removes the need for much of the iterative trial-and-error decomposition of an expression into targets. Isolated problematic frames of an animation are re-sculpted as desired and used as training for a nonparametric regression that associates these shapes with the underlying blendshape weights. Using this technique, the artist’s correction to a problematic expression is automatically applied to similar expressions in an entire sequence, and indeed to all future sequences. The extent and falloff of editing is controllable and the effect is continuously propagated to all similar expressions. In addition, we present a search scheme that allows effective reuse of pre-sculpted editing examples. Our system greatly reduces time and effort required by animators to create high quality facial animations.

From dummies to animations: a review of computer-animated stimuli used in animal behavior studies

Traditionally, studies that explored animal communication have been directed towards the observation of natural interactions between individuals. Over the years, researchers have long championed the use of artificial stimuli in place of natural ones in behavioral experiments to precisely control what the observers get to see or experience. The employment of diverse techniques to stage animal interactions has provided an alternative to observations and intrusive experimental methods. Technological advances now allow researchers to develop realistic computer animations of social partners that mimic behaviors with a high degree of fidelity for morphological and behavioral characteristics of tutors. The increasing use of the computer-generated animations technique reveals a desire to deliver standardized visual stimuli and to limit the variable behavior of demonstrators across experimental sessions. In the following review, we provide an appraisal of the computer-generated animations efficiency to stage animal interactions, and consider experimental studies in which this technique has been employed to simulate social interactions. We also present alternative methods that are used for designing animation models. Our aim is to evaluate the merits of computer-generated animations and how this technique may be more appropriate for certain types of staged interactions when compared to other classically employed approaches. We advocate that computer-generated animations appear to be the most flexible technique to date, and offers better control of visual cues that are presented, thus allowing researchers to program a large variety of stimuli. Finally, we suggest improvements of this technique, and especially how it may be used to study signal design in multimodal systems.

Closed Traumatic Brain Injury Model in Sheep Mimicking High-Velocity, Closed Head Trauma in Humans

To date, there are only a few, non-evidence based, cerebroprotective therapeutic strategies for treatment and, accordingly, for prevention of secondary brain injuries following severe closed head trauma. In order to develop new therapy strategies, existing realistic animal models need to be advanced. The objective is to bridge standardized small animal models and actual patient medical care, since the results of experimental small animal studies often cannot be transferred to brain-injured humans. For improved standardization of high-velocity trauma, new trauma devices for initiating closed traumatic brain injury in sheep were developed. The following new devices were tested: 1. An anatomically shaped rubber bolt with an integrated oscillation absorber for prevention of skull fractures; 2. Stationary mounting of the bolt to guarantee stable experimental conditions; 3. Varying degrees of trauma severity, i. e., mild and severe closed traumatic brain injury, using different cartridges; and 4. Trauma analysis via high-speed video recording. Peritraumatic measurements of intracranial pressure, brain tissue pH, brain tissue oxygen, and carbon dioxide pressure, as well as neurotransmitter concentrations were performed. Cerebral injuries were documented with magnetic resonance imaging and compared to neuropathological results. Due to the new trauma devices, skull fractures were prevented. The high-speed video recording documented a realistic trauma mechanism for a car accident. Enhancement of extracellular glutamate, aspartate, and gamma amino butyric acid concentrations began 60 min after the trauma. Magnetic resonance imaging and neuropathological results showed characteristic injury patterns of mild, and severe, closed traumatic brain injury. The severe, closed traumatic brain injury group showed diffuse axonal injuries, traumatic subarachnoid hemorrhage, and hemorrhagic contusions with inconsistent distribution among the animals. The model presented here achieves a gain in standardization of severe, closed traumatic brain injury by increasing approximation to reality. The still existent heterogeneity of brain pathology mimics brain changes observed in patients after high-energy trauma. This model seems to close the gap between experimental small animal models and clinical studies. However, further investigations are needed to evaluate if this model can be used for testing new therapeutic strategies for these patients.

MAYA를 이용한 3D게임 캐릭터 디자인

스마트폰 환경에서 하드웨어인 폰(Phone)은 CPU 처리 속도 향상, 3D 엔진 탑재, 가용량 메모리 확대 등으로 인하여 차세대 스마트폰 게임 시장이 활발하게 떠오르고 있다. 또한 3D 게임 캐릭터설정에 있어서, 작은 스마트폰 화면에서 사실적이고 자유로운 애니메이션이 중요한 부분이 되고 있다. 본 연구에서는 캐릭터 설정과 스마트폰에서 효과적으로 3D 게임 캐릭터가 체감을 유발할 수 있는 조작 방법으로, MAYA를 활용하여 NURBS 데이터로 눈에서 코 그리고 입으로 얼굴을 완성하고, Polygon Cube tool로 손과 발을 모델링하였다. 그리고 하나의 큐브를 반으로 나누어 모델링 한 후 mirror 복사를 통해서 바디의 전체를 완성시켜 로우폴리곤 모델링하였다. 그 다음 사실감 있고 자연스러운 캐릭터를 모델링하기 위해 ZBrush로 디테일 완성하고 Divide의 레벨을 4까지 적용하였다. 다소 거칠거나 과장된 형태일지라도 들어갈 곳과 나올 곳 등을 표현해가며 Smooth 브러시 효과로 부드럽게 표현하고 매핑하여 로우폴리곤 3D 캐릭터를 설계하였다. 3D engines loading, and expansion of the usable capacity, next-generation smartphone game markets are rising briskly by the improvement in CPU processing speed of Phones (hardware of smartphone). Therefore, in creating 3D game characters, realistic and free-form animations in a small screen of a smartphone are becoming important. Through this paper, as a method of creating characters and operating for game characters to cause user's feeling, with NURBS data of MAYA, We completed a face in turns of eyes, a nose, and a mouth, and with Polygon Cube tool, modeled hands and feet. After dividing a cube into half and modeling it, through mirror copying We completed the whole body and modeled the low-polygon. Then to model realistic and free-form characters, We completed each detail with ZBrush and applied Divide level up to 4. Though they might look rough and exaggerated, We tried to express stuck-out parts and fallen-in parts effectively and smoothly with Smooth brush effect, map and design the low-polygon 3D characters.

SU‐C‐211‐05: Improved Target Localization with Integrated X‐Ray/bioluminescent Tomography

Purpose: Bioluminescence tomography (BLT) is a promising approach to guide focal irradiation of pre‐palpable tumors in small animals, but is limited in resolution. In this study, we investigate the use of x‐ray and diffuse optical tomography tomography to provide spatial and optical information about the object to improve BLT reconstruction. Methods: In a 3‐step approach, x‐ray CBCT is used first to provide the anatomic spatial information about the object. Secondly, photons of different wavelengths are transmitted through the object for detection by a CCD camera. The optical properties of the anatomic regions are then found by solutions of the diffuse optical tomography problem. In the final step, the anatomic and optical “priors” are employed in BLT reconstruction, where optical filters are used again to extract the multi‐spectral information required to derive the position and power of the internal source. The approach was tested in an experimental setup where a 1.5 mm diameter (dia) optical fiber light source was inserted at 5 different lateral positions in a 12 mm dia optical heterogeneity within a 25 mm dia cylindrical tissue‐mimicking phantom. The reconstructed positions and powers were compared with the known inputs. Results: The average error in locating the source centroid was 0.13 mm, range 0.3 mm to 0 mm. The average error in source power estimations was 9%, range 14% to −1%. The results are an improvement over commercial systems that typically have an average localization uncertainty of 1 mm and error in power estimation of more than 20%. Conclusions: The spatial and spectral prior information provided by x‐ray CT and diffuse optical tomography improves the accuracy of BLT. Integrated x‐ray/BL tomographic capability on board new small animal radiation research systems can contribute significantly to accurate biological targeting in realistic animal models.J Wong has a sponsored research agreement with Xstrahl Ltd on small animal radiation research.

Physically valid statistical models for human motion generation

This article shows how statistical motion priors can be combined seamlessly with physical constraints for human motion modeling and generation. The key idea of the approach is to learn a nonlinear probabilistic force field function from prerecorded motion data with Gaussian processes and combine it with physical constraints in a probabilistic framework. In addition, we show how to effectively utilize the new model to generate a wide range of natural-looking motions that achieve the goals specified by users. Unlike previous statistical motion models, our model can generate physically realistic animations that react to external forces or changes in physical quantities of human bodies and interaction environments. We have evaluated the performance of our system by comparing against ground-truth motion data and alternative methods.

Real‐time smoke simulation with improved turbulence by spatial adaptive vorticity confinement

AbstractTurbulence modeling has recently drawn many attentions in fluid animation to generate small‐scale rolling features. Being one of the widely adopted approaches, vorticity confinement method re‐injects lost energy dissipation back to the flow. However, previous works suffer from deficiency when large vorticity coefficient ε is used, due to the fact that constant ε is applied all over the simulated domain. In this paper, we propose a novel approach to enhance the visual effect by employing an adaptive vorticity confinement which varies the strength with respect to the helicity instead of a user‐defined constant. To further improve fine details in turbulent flows, we are not only applying our proposed vorticity confinement to low‐resolution grid, but also on a finer grid to generate sub‐grid level turbulence. Since the incompressible Navier–Stokes equations are solved only in low‐resolution grid, this saves a significant amount of computation. Several experiments demonstrate that our method can produce realistic smoke animation with enhanced turbulence effects in real‐time. Copyright © 2011 John Wiley & Sons, Ltd.

Exploring Non‐Linear Relationship of Blendshape Facial Animation

AbstractHuman face is a complex biomechanical system and non‐linearity is a remarkable feature of facial expressions. However, in blendshape animation, facial expression space is linearized by regarding linear relationship between blending weights and deformed face geometry. This results in the loss of reality in facial animation. To synthesize more realistic facial animation, aforementioned relationship should be non‐linear to allow the greatest generality and fidelity of facial expressions. Unfortunately, few existing works pay attention to the topic about how to measure the non‐linear relationship. In this paper, we propose an optimization scheme that automatically explores the non‐linear relationship of blendshape facial animation from captured facial expressions. Experiments show that the explored non‐linear relationship is consistent with the non‐linearity of facial expressions soundly and is able to synthesize more realistic facial animation than the linear one.

Frame design and implementation of realistic and controllable fire animation

This paper presented a general fire simulation frame including three stages:pre-processing,fire simulation and post-processing.In order to implement this fire animation frame,the corresponding solutions were provided to address the key issues in every stage.Based on the two-phase flow characteristics of fire and the performance of turbulence fluid,a turbulence model using limited computing resources was proposed to rich the flame details.The experimental results show the effectiveness of the proposed flame simulation frame which can generate not only the basic fire phenomena but also other fire animations under the control of complex curves or surfaces and spreading rules.

Generating Real-Time Responsive Balance Recovery Animation

We propose a novel Biomechanics-based Responsive Balance Recovery (BRBR) technique for synthesizing realistic balance recovery animations. First, our BRBR technique is based on a simplified human biomechanical model of keeping balance, so as to interactively respond to contact forces in the environment. Then, we employ the Principal Component Analysis (PCA) to reduce the dimensions of the mocap (motion capture) database to ensure the search for the most qualified return-to segment in real-time. Finally, empirical results from three cases validate the approach.

Scan-Based Volume Animation Driven by Locally Adaptive Articulated Registrations

This paper describes a complete system to create anatomically accurate example-based volume deformation and animation of articulated body regions, starting from multiple in vivo volume scans of a specific individual. In order to solve the correspondence problem across volume scans, a template volume is registered to each sample. The wide range of pose variations is first approximated by volume blend deformation (VBD), providing proper initialization of the articulated subject in different poses. A novel registration method is presented to efficiently reduce the computation cost while avoiding strong local minima inherent in complex articulated body volume registration. The algorithm highly constrains the degrees of freedom and search space involved in the nonlinear optimization, using hierarchical volume structures and locally constrained deformation based on the biharmonic clamped spline. Our registration step establishes a correspondence across scans, allowing a data-driven deformation approach in the volume domain. The results provide an occlusion-free person-specific 3D human body model, asymptotically accurate inner tissue deformations, and realistic volume animation of articulated movements driven by standard joint control estimated from the actual skeleton. Our approach also addresses the practical issues arising in using scans from living subjects. The robustness of our algorithms is tested by their applications on the hand, probably the most complex articulated region in the body, and the knee, a frequent subject area for medical imaging due to injuries.

A Fuzzy Clustering Algorithm for Virtual Character Animation Representation

The use of realistic humanoid animations generated through motion capture (MoCap) technology is widespread across various 3-D applications and industries. However, the existing compression techniques for such representation often do not consider the implicit coherence within the anatomical structure of a human skeletal model and lacks portability for transmission consideration. In this paper, a novel concept virtual character animation image (VCAI) is proposed. Built upon a fuzzy clustering algorithm, the data similarity within the anatomy structure of a virtual character (VC) model is jointly considered with the temporal coherence within the motion data to achieve efficient data compression. Since the VCA is mapped as an image, the use of image processing tool is possible for efficient compression and delivery of such content across dynamic network. A modified motion filter (MMF) is proposed to minimize the visual discontinuity in VCA's motion due to the quantization and transmission error. The MMF helps to remove high frequency noise components and smoothen the motion signal providing perceptually improved VCA with lessened distortion. Simulation results show that the proposed algorithm is competitive in compression efficiency and decoded VCA quality against the state-of-the-art VCA compression methods, making it suitable for providing quality VCA animation to low-powered mobile devices.

Data-driven facial expression synthesis via Laplacian deformation

Realistic talking heads have important use in interactive multimedia applications. This paper presents a novel framework to synthesize realistic facial animations driven by motion capture data usin...

Simulation of longitudinal geometric yarn structure

A useful yarn model is certainly a valuable tool for yarn technologists involved in the process of product development that is why this study is to present a three-dimensional environment for the virtual design and the simulation of a yarn, the emphasis being on the yarn structure. To integrate the model of the yarn in the fabric model, we must define a geometry adapted to the yarn and describe the behaviour of the yarn model, for that, an algorithm of modelling the fibres in 3D has been developed. Beyond the scientific character of the forecast, one can use the same computerised base to virtually simulate the tests and laboratory experiments or to generate realistic animations in artistic matter and design of textile clothing.