APPLICATION OF COMPUTER GRAPHICS IN MARTENSITIC TRANSFORMATION

This paper discuss the stereographic method of martensitic transformation (MT)in the view of computer graphics (CG) and programs are programmed to realize this method. Habit plane resulting from the programs agrees with that of numerical analysis in terms of the lattice parameters of austenite and martensite and shear mechanism supposed in Fe-22%Ni-0.8%C alloy, so does orientation relationships.

PHOTOREALISTIC COMPUTER GRAPHICS FORENSICS BASED ON LEADING DIGIT LAW

As the advent and growing popularity of image rendering software,photorealistic computer graphics are becoming more and more perceptually indistinguishable from photographic images.If the faked images are abused,it may lead to potential social,legal or private consequences.To this end,it is very necessary and also challenging to find effective methods to differentiate between them.In this paper,a novel leading digit law,also called Benford's law,based method to identify computer graphics is proposed.More specifically,statistics of the most significant digits are extracted from image's Discrete Cosine Transform(DCT) coefficients and magnitudes of image's gradient,and then the Support Vector Machine(SVM) based classifiers are built.Results of experiments on the image datasets indicate that the proposed method is comparable to prior works.Besides,it possesses low dimensional features and low computational complexity.

Three-Dimensional Space Interpolation of Grey / Depth Image Sequence-A New Technique of Computer Graphics Synthesis

This paper advances a three-dimensional space interpolation method of grey / depth image sequence, which breaks free from the limit of original practical photographing route. Pictures can cruise at will in space. By using space sparse sampling, great memorial capacity can be saved and reproduced scenes can be controlled. To solve time consuming and complex computations in three-dimensional interpolation algorithm, we have studied a fast and practical algorithm of scattered space lattice and that of 'Warp' algorithm with proper depth. By several simple aspects of three dimensional space interpolation, we succeed in developing some simple and practical algorithms. Some results of simulated experiments with computers have shown that the new method is absolutely feasible.

Trends in Computer Graphics for the 1990's

We look at expected developments in computer graphics system capabilities for the next decade.the underlying thrust is an expected system hardware capability increase of around 50% per year.Memory sizes are expected to double every 12 to 18 months.Most of this system capability in- crease will be used in better and more elaborate simulations,detailed analyses of experimental and com- puted data(i.e.visualization)and more convenient user inputs.The overall effect by the end of the decade will be an increase in simulation capabilties of about fifty-fold,bringing affordable detailed analy- sis and interpretation of data to all engineering,scientific and business enterprises.Concomitant with these system growths is a need to re-examine graphics algorithms with the view of effectively utilizing the vastly increased memory sizes and employing specialized autonomous parallel computing structure.

Discriminating between photorealistic computer graphics and natural images using fractal geometry

Rendering technology in computer graphics （CG） is now capable of producing highly photorealistic images, giving rise to the problem of how to identify CG images from natural images. Some methods were proposed to solve this problem. In this paper, we give a novel method from a new point of view of image perception. Although the photorealistic CG images are very similar to natural images, they are surrealistic and smoother than natural images, thus leading to the difference in perception. A pert of features are derived from fractal dimension to capture the difference in color perception between CG images and natural images, and several generalized dimensions are used as the rest features to capture difference in coarseness. The effect of these features is verified by experiments. The average accuracy is over 91.2%.

Visual Simulation of Multiple Fluids in Computer Graphics： A State-of-the-Art Report

Realistic animation of various interactions between multiple fluids, possibly undergoing phase change, is a challenging task in computer graphics. The visual scope of multi-phase multi-fluid phenomena covers complex tangled surface structures and rich color variations, which can greatly enhance visual effect in graphics applications. Describing such phenomena requires more complex models to handle challenges involving the calculation of interactions, dynamics and spatial distribution of multiple phases, which are often involved and hard to obtain real-time performance. Recently, a diverse set of algorithms have been introduced to implement the complex multi-fluid phenomena based on the governing physical laws and novel discretization methods to accelerate the overall computation while ensuring numerical stability. By sorting through the target phenomena of recent research in the broad subject of multiple fluids, this state-of-the-art report summarizes recent advances on multi-fluid simulation in computer graphics.

Future Trends in Computer Graphics： How Much is Enough？

Over the forty-year history of interactive computer graphics, there have beencontinuous advances, but at some stage this progression must terminate with images beingsufficiently realistic for all practical purposes. How much detail do we really need? Polygon countsover a few million imply that on average each polygon paints less than a single pixel, making useof polygon shading hardware wasteful. We consider the problem of determining how much realism isrequired for a variety of applications. We discuss how current trends in computer graphics hardware,and in particular of graphics cards targeted at the computer games industry, will help or hinderachievement of these requirements. With images now being so convincingly realistic in many cases,critical faculties are often suspended and the images are accepted as correct and truthful althoughthey may well be incorrect and sometimes misleading or untruthful. Display resolution has remainedlargely constant in spatial terms for the last twenty years and in terms of the number of pixels hasincreased by less than an order of magnitude. If the long-promised breakthroughs in displaytechnology are finally realised, how should we use the increased resolution?

A review of computer graphics approaches to urban modeling from a machine learning perspective

Urban modeling facilitates the generation of virtual environments for various scenarios about cities.It requires expertise and consideration,and therefore consumes massive time and computation resources.Nevertheless,related tasks sometimes result in dissatisfaction or even failure.These challenges have received significant attention from researchers in the area of computer graphics.Meanwhile,the burgeoning development of artificial intelligence motivates people to exploit machine learning,and hence improves the conventional solutions.In this paper,we present a review of approaches to urban modeling in computer graphics using machine learning in the literature published between 2010 and 2019.This serves as an overview of the current state of research on urban modeling from a machine learning perspective.

A Computer Graphics-Based Framework for 3D Pose Estimation of Pedestrians

In pedestrian-to-vehicle collision accidents,adapting safety measures ahead of time based on actual pose of pedestrians is one of the core objectives for integrated safety.It can significantly enhance the performance of passive safety system when active safety maneuvers fail to avoid accidents.This study proposes a deep learning model to estimate 3D pose of pedestrians from images.Since conventional pedestrian image datasets do not have available pose features to work with,a computer graphics-based(CG)framework is established to train the system with synthetic images.Biofidelic 3D meshes of standing males are first transformed into several walking poses,and then rendered as images from multiple view angles.Subsequently,a matrix of 50 anthropometries,10 gaits and 12 views is built,in total of 6000 images.A two-branch convolutional neural network(CNN)was trained on the synthetic dataset.The model can simultaneously predict 16 joint landmarks and 14 joint angles of pedestrian for each image with high accuracy.Mean errors of the predictions are 0.54 pixels and−0.06°,respectively.Any specific pose can then be completely reconstructed from the outputs.Overall,the current study has established a CG-based pipeline to generate photorealistic images with desired features for the training;it demonstrates the feasibility of leveraging CNN to estimate the pose of a walking pedestrian from synthesized images.The proposed framework provides a starting point for vehicles to infer pedestrian poses and then adapt protection measures accordingly for imminent impact to minimize pedestrian injuries.

Call for Papers Special Issue of Tsinghua Science and Technology on Visualization and Computer Graphics

Tsinghua Science and Technology was started publication in 1996. It is an international academic journal sponsored by Tsinghua University and is published bimonthly. This journal aims at presenting the up-to-date scientific achievements in computer science and other IT fields. It is indexed by Ei and other abstracting indexes. From 2012, the journal enters into IEEE Xplore Digital Library

Blended Teaching Mode Based on“Cloud Class+PAD Class”in the Course of Computer Graphics and Image Design

As a teaching tool,Cloud class is specially developed for teaching and learning in mobile circumstance,and the PAD(Presentation Assimilation Discussion)class acts as a creative teaching mode.The combination of Cloud class and PAD class helps build online-offline blended teaching model.In this paper,a Cloud+PAD class mode is proposed.An experiment of teaching is implemented and the practical effectiveness is evaluated and verified.The experimental results show,compared with the conventional teaching method,the proposed teaching mode is capable of creating more high-level,innovative and complex teaching content,and thereby noticeably enhancing students’learner autonomy and motivating them to develop creativity.

Graphics Evolutionary Computations in Higher Order Parametric Bezier Curves

This work demonstrates in practical terms the evolutionary concepts and computational applications of Parametric Curves.Specific cases were drawn from higher order parametric Bezier curves of degrees 2 and above.Bezier curves find real life applications in diverse areas of Engineering and Computer Science,such as computer graphics,robotics,animations,virtual reality,among others.Some of the evolutionary issues explored in this work are in the areas of parametric equations derivations,proof of related theorems,first and second order calculus related computations,among others.A Practical case is demonstrated using a graphical design,physical hand sketching,and programmatic implementation of two opposite-faced handless cups,all evolved using quadratic Bezier curves.The actual drawing was realized using web graphics canvas programming based on HTML 5 and JavaScript.This work will no doubt find relevance in computational researches in the areas of graphics,web programming,automated theorem proofs,robotic motions,among others.

COMPUTER SIMULATION IN MAN-MACHINE-ENVIRONMENT SYSTEM ENGINEERING

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Exploring Image Generation for UAV Change Detection

Change detection(CD)is becoming indispensable for unmanned aerial vehicles(UAVs),especially in the domain of water landing,rescue and search.However,even the most advanced models require large amounts of data for model training and testing.Therefore,sufficient labeled images with different imaging conditions are needed.Inspired by computer graphics,we present a cloning method to simulate inland-water scene and collect an auto-labeled simulated dataset.The simulated dataset consists of six challenges to test the effects of dynamic background,weather,and noise on change detection models.Then,we propose an image translation framework that translates simulated images to synthetic images.This framework uses shared parameters(encoder and generator)and 22×22 receptive fields(discriminator)to generate realistic synthetic images as model training sets.The experimental results indicate that:1)different imaging challenges affect the performance of change detection models;2)compared with simulated images,synthetic images can effectively improve the accuracy of supervised models.

ON HIGH DIMENSIONAL INTERPOLATION

This paper introduces the definition of the Orthogonal Type Node Configuration and discusses the corresponding multivariate Lagrange, Hermite and Birkhoff interpolation problems in high dimensional space R s(s>2). This node configuration can be considered to be a kind of extension of the Cross Type Node Configuration , in R 2 to high dimensional spaces. And the Mixed Type Node Configuration in R s(s>2) is also discussed in this paper in an example.

An efficient adaptive space partitioning algorithm for electromagnetic scattering calculation of complex 3D models

The space partitioning algorithm based on the rounding and addressing operations has been proved to be an efficient space partitioning algorithm with the potential for real-time calculation.An improvement on this kind of space partitioning algorithms for solving complex 3D models is presented.Numerical examples show that the efficiency of the improved algorithm is better than that of the original method.When the size of most target elements is smaller than the size of spatial grids,the efficiency of the improved method can be more than four times of that of the original method.An adaptive method of space partitioning based on the improved algorithm is developed by taking the surface element density or the curvature as the threshold for deep partitioning and conducting the deep partitioning using the octree method.A computer program implementation for applying the method in some typical applications is discussed,and the performance in terms of the efficiency,reliability,and resource use is evaluated.Application testing shows that the results of the adaptive spacing partitioning are more convenient for the follow-up use than that of the basic uniform space partitioning.Furthermore,when it is used to calculate the electromagnetic scattering of complex targets by the ray tracing(RT)method,the adaptive space partitioning algorithm can reduce the calculation time of the RT process by more than 40%compared with the uniform space segmentation algorithm.

Study and Realization of Intelligent Online Drawing Platform Based on Internet

Internet has gradually demonstrated more and more superiority in modern education system. The intelligent online drawing platform based on net will provide learners with a studying environment without limitation in time and space. Based on the theory of graphics, this paper developed an intelligent online drawing platform (IODP) with Java through analyzing the teaching character of descriptive geometry. IODP developed not only has a flexible drawing environment with the function of mutual drawing, but also is able to judge the drawing made by students and give feedback at the same time. This platform gives an effective way for Internet education on engineering graphics.

Object-Oriented Design for FDTD Visual Scientific Computing

A scheme for general purposed FDTD visual scientific computing software is introduced in this paper using object-oriented design (OOD) method. By abstracting the parameters of FDTD grids to an individual class and separating from the iteration procedure, the visual software can be adapted to more comprehensive computing problems. Real-time gray degree graphic and wave curve of the results can be achieved using DirectX technique. The special difference equation and data structure in dispersive medium are considered, and the peculiarity of parameters in perfectly matched layer are also discussed.