Sensory state machines for physically-based animation

In this paper, we propose a flexible representation of controllers that uses high-level sensors and possesses a general and intuitive structure that offers several types of parameters, which can be modified either automatically or with the animator’s intervention. This structure, with the feedback signals provided by its sensors, allows several state machines to act simultaneously on the model, or in a subset of its actuators. The sensors can be optimized, facilitating their definition and use. The representation also permits the animator to define procedures with general instructions that can be automatically executed by the controller during the dynamics simulation.     

Fragment shaders for agent animation using finite state machines

In a previous paper we generated animated agents and their behavior using a combination of XML and images. The behavior of agents was specified as a finite state machine (FSM) in XML. We used images to determine properties of the world that agents react to. While this approach is very flexible, it can be made much faster by using the power available in modern GPUs. In this paper we implement FSMs as fragment shaders using three kinds of images: world space images, agent space images and FSM table images. We show a simple example and compare performance of CPU and GPU implementations. Then we examine a more complex example involving more maps and two types of agents (predator–prey). Furthermore we explore how to render agents in 3D more efficiently by using a variation on pseudoinstancing.     

语音驱动的人脸动画研究现状综述

利用语音来驱动人脸动画,是虚拟现实（Virtual Reality）等领域重要的智能技术,近年来虚拟现实技术的飞速发展更进一步地突出了在沉浸环境下的人机自然交流的迫切需求。语音驱动的人脸动画技术能够创造出自然生动、带有情感的动画,相对于传统预设的人脸动画而言能够更好地辅助人机交互、提升用户体验。为推进该技术的智能化程度和应用,针对语音驱动人脸动画的关键问题：音视频映射,综述了逐帧分析、多帧分析和逐音素分析的映射方法,同时也梳理了多种脸部模型的思想,动画合成、情感融合、人脸动画评价的方法,及可能的研究发展方向。     

Skeleton driven animation based on implicit skinning

Skeleton-driven animation methods have been commonly used in animating 3D characters. In these methods, a skinning process that binds the character surface onto the skeleton is required. This process is usually accomplished manually and is a time-consuming task. In this paper, we propose a novel method for automatically skinning skeletal character models. Given the motion of a skeleton, our method can animate the character model automatically. In our method, each joint coordinate is parameterized by its surrounding local surface. In such a way, the character's surface is implicitly bound onto the skeleton. Character animation is achieved by minimizing an energy function that is carefully designed to prevent unnatural volume changes and to guarantee smooth deformations. Experiments demonstrate the efficiency and excellent performance of our method.     

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.     

Communicating real-time state machines

Communicating real-time state machines (CRSMs), a complete and executable notation for specifying concurrent real-time systems including the monitored and controlled physical environment, are introduced. They are essentially state machines that communicate synchronously in a manner much like the input-output in Hoare's CSP. In addition, CRSMs have a novel and small set of facilities for describing timing properties and accessing real time. The author defines the CRSM language, gives many examples of its use in requirements specification, outlines an algorithm for executing or simulating CRSMs, introduces some techniques for reasoning about the specifications, and discusses some open problems and issues     

Discontinuities driven by a billion connected machines

We have witnessed an explosion of Internet use that has tremendous implications for our industry, particularly on the test requirements put upon us. At Intel we have a vision. We see a world in which we're marching toward a billion connected computers being served by high-performance networks and millions of servers. On those servers we see billions of transactions worth trillions of dollars, conducted on a daily and a yearly basis. This connected world is changing everything-everything that we do and everything that we need to deliver as an industry     

Performance‐driven muscle‐based facial animation

We describe a system to synthesize facial expressions by editing captured performances. For this purpose, we use the actuation of expression muscles to control facial expressions. We note that there have been numerous algorithms already developed for editing gross body motion. While the joint angle has direct effect on the configuration of the gross body, the muscle actuation has to go through a complicated mechanism to produce facial expressions. Therefore,we devote a significant part of this paper to establishing the relationship between muscle actuation and facial surface deformation. We model the skin surface using the finite element method to simulate the deformation caused by expression muscles. Then, we implement the inverse relationship, muscle actuation parameter estimation, to find the muscle actuation values from the trajectories of the markers on the performer's face. Once the forward and inverse relationships are established, retargeting or editing a performance becomes an easy job. We apply the original performance data to different facial models with equivalent muscle structures, to produce similar expressions. We also produce novel expressions by deforming the original data curves of muscle actuation to satisfy the key‐frame constraints imposed by animators.Copyright © 2001 John Wiley & Sons, Ltd.     

Data‐driven detailed hair animation for game characters

We propose a data‐driven method to realize high‐quality detailed hair animations in interactive applications like games. By devising an error metric method to evaluate hair animation similarities, we take hair features into consideration as much as possible. We also propose a novel database construction algorithm based on Secondary Motion Graph. Our algorithm can improve the efficiency of such graphs to reduce redundant data and also achieves visually smooth connection of two animation clips while taking into consideration their future motions. The costs for the run‐time process using our Secondary Motion Graph are relatively low, allowing real‐time interactive operations. Copyright © 2016 John Wiley & Sons, Ltd.     

Computing refactorings of state machines

For behavior models expressed in statechart-like formalisms, we show how to compute semantically equivalent yet structurally different models. These refactorings are defined by user-provided logical predicates that partition the system’s state space and that characterize coherent parts – modes or control states–of the behavior. We embed the refactorings into an incremental development process that uses a combination of both tables and graphically represented state machines for describing systems.     

Combining programs and state machines

State machines consume and process actions complementary to programs issuing actions. State machines maintain a state and reply with a boolean response to each action in their interface. As state machines offer a service to programs, their interface is also called a service interface. State machines can be combined with several natural operators, thus giving rise to a state machine calculus. State machines are used for abstract data type modeling.     

Institutionalising UML 2.0 state machines

A key challenge to achieve a unified semantics for UML is how to handle the heterogeneity of its sublanguages. In this context, the theory of institutions provides an elegant and robust framework for programming in the large and in particular for compositionality. It can be used to define a family of formalisms which capture various UML sublanguages, and morphisms that represent the expected semantic relationships between them, resulting in a heterogeneous environment for the semantic definition of UML. The main goal of this work is to collaborate with the definition of such environment. For this purpose, we define an institution for UML 2.0 state machines. The building blocks of our institution are based on a previous semantics dealing with processing simple input events within a transition step. We also extend these semantic definitions for handling sequences of events, and then for considering runs through the state machine.     

Solving satisfiability via Boltzmann machines

Boltzmann machines (BMs) are proposed as a computational model for the solution of the satisfiability (SAT) problem in the propositional calculus setting. Conditions that guarantee consensus function maxima for configurations of the BM associated with solutions to the satisfaction problem are given. Experimental results that show a linear behavior of BMs solving the satisfiability problem are presented and discussed     

On state reduction of incompletely specified finite state machines

State reduction of incompletely specified finite state machines (ISFSMs) is an important task in optimization of sequential circuit design and known as an NP-complete problem. Removal of redundant states reduces the logic, because of this, chip area decreases. In addition, test generation is easier when the sequential circuit is irredundant. In this paper, we present a heuristic for state reduction of ISFSMs. The proposed heuristic is based on a branch-and-bound search technique and identification of sets of compatible states of a given ISFSM specification. We have obtained results as good as the best exact method in the literature but with significantly better run-times.     

Synthesis of finite state machines for improved state verification

Finite State Machines (FSMs) are used in diverse areas to model hardware and software systems. Verification of FSMs is essential to ensure reliability of systems. To verify that a machine is in an expected state in testing, Unique Input/Output (UIO) sequences are used. The aforementioned testing methodology requires that each state in the FSM has an UIO. However, it is possible for a given machine that few or even none of its states have an UIO sequence. This paper presents a guided heuristic algorithm for synthesizing FSMs such that each state has an UIO sequence. The states of an FSM with identical I/O labels on transitions are grouped in order to identify the states which do not possess UIO sequence. The transitions are then augmented by adding extra output terminals incrementally so that new UIO sequences are created for the states. A greedy approach is used to optimize the number of added outputs. Initially, the transitions which lead to state convergence (i.e., transitions with identical input/output labels taking a set of states to the same next state) and constrained self-loop (i.e., transitions taking a set of states either to itself or leads to state convergence) are identified since a state with only these transitions will never have a UIO sequence. Extra output terminals are added to the FSM which are used only while testing and the augmented output labels make sure that the states are neither convergent nor has constrained self-loop, thereby ensuring UIO sequence. The proposed algorithm, referred to as AUGP, was tested with a large number of FSMs including the Microelectronics Center of North Carolina (MCNC) FSM benchmarks. The augmented state transition table was used as input to a UIO computation algorithm (developed by the same authors [Ahmad I, et al. IEE Proc Comput Digital Tech 2004;151(2):131]) to check the performance of the augmentation algorithm and the tested FSMs were found to possess UIO sequence for all states.     

扰动模糊有限转换状态机

引入了扰动模糊有限转换状态机和扰动模糊有限状态机的（强）同态的概念,研究了它们的相关性质。给出了[Σ]的元素构成所有长度有限的词集上的两种同余关系,讨论商结构问题,证明了相应的所有等价类构成具有单位元的有限半群,并且这两个有限半群是同态的。给出了[Q]上容许关系及强同态的核的概念,研究了它们的相关性质。     

Incremental testing of finite state machines

The automatic generation of test suites for systems modelled as finite state machines (FSMs) is an important problem that impacts several critical applications. Known methods that automatically generate tests for FSMs, specially the W‐method and some derivations, strongly assume that the number of system states is small. If the overall number of states in the FSM specification is relatively large, such methods become difficult to use. However, often in practice, a system is defined as a combination of several subsystems, with the latter already independently designed, developed and tested. In this paper, we define the concept of combined FSMs and introduce a new method to test modular compositions of FSMs. This method allows for a new incremental testing strategy that turns the testing of new systems into a much more scalable process. As an example, we present an infinite family of naturally occurring FSM models for which our method produces exponentially more compact test suites than the W‐method. Copyright © 2012 John Wiley & Sons, Ltd.