A survey of real-time rendering on Web3D application

Background In recent years, with the rapid development of mobile Internet and Web3D technologies, a large number of web-based online 3D visualization applications have emerged. Web3D applications, including Web3D online tourism, Web3D online architecture, Web3D online education environment, Web3D online medical care, and Web3D online shopping are examples of these applications that leverage 3D rendering on the web. These applications have pushed the boundaries of traditional web applications that use text, sound, image, video, and 2D animation as their main communication media, and resorted to 3D virtual scenes as the main interaction object, enabling a user experience that delivers a strong sense of immersion. This paper approached the emerging Web3D applications that generate stronger impacts on people's lives through “real-time rendering technology”, which is the core technology of Web3D. This paper discusses all the major 3D graphics APIs of Web3D and the well-known Web3D engines at home and abroad and classify the real-time rendering frameworks of Web3D applications into different categories. Results Finally, this study analyzed the specific demand posed by different fields to Web3D applications by referring to the representative Web3D applications in each particular field. Conclusions Our survey results show that Web3D applications based on real-time rendering have in-depth sectors of society and even family, which is a trend that has influence on every line of industry.

Real-Time Rendering of Large-Scale Ocean Environments

Simulation and rendering of large-scale natural environments, especially the ocean, has always been one of the hot issues in computer graphics, which can provide realism for various applications such as computer game, movie and military usage. Simulation of ocean environment is often lack of realism for real-time application due to its complexity of dynamic waves. In this paper, a method based on FFT Wave model is proposed to solve this problem, which can also simulate the ocean optic property with atmosphere scattering. Furthermore, our method has a lot of advantages including global ocean dataset support, real-time, dynamic reflection of ocean, the foam on the wave, smooth transition from deep ocean to seacoast, etc. The experimental results demonstrate the realism and effectiveness of our approach.

Real-Time Rendering of Dynamic Clouds Using Multi-Resolution Adaptive Grids

The multi-resolution adaptive grids method is proposed to solve the problems of inefficiency in the previous grid-based methods,and it can be used in clouds simulation as well as the interactive simulation between objects and clouds.Oriented bounding box(OBB)hierarchical trees of objects are established,and the resolutions of global and local grids can be selected automatically.The motion equations of fluid dynamics are simplified.Upwind difference is applied to ensure the stability of the simulation process during the discrete process of partial differential equations.To solve the speed problem of existed phase functions,the improved phase function is applied to the illumination calculation of clouds.Experimental results show that the proposed methods can promote the simulation efficiency and meet the need for the simulation of large-scale clouds scene.Real-time rendering of clouds and the interaction between clouds and objects have been realized without preprocessing stage.

Shadow Volume in Real-Time Rendering

This paper presents an optimization of shadow volume algorithm, which allow a rendering in real-time. This technique is based on previous works which makes it possible to obtain shadows in real-time, although the calculation of the silhouette requires a pretreatment of the geometry implemented on the CPU （Central Processing Unit）. By using last version of the GPU （Graphic Processing Unit）, the authors propose to implement the calculation of the silhouette on the GPU by using Geometry Shader. The authors present the step which made it possible to lead to a concrete implementation of this algorithm, the modifications which were made, as well as a comparative study of results, followed by a discussion of these results and choices of implementation.

Two-phase real-time rendering method for realistic water refraction

Background Realistic rendering has been an important g oal of several interactive applications,which requires an efficient virtual simulation of many special effects that are common in the real world.However,refraction is often ignored in these applications.Rendering the refraction effect is extremely complicated and time-consuming.Methods In this study,a simple,efficient,and fast rendering technique of water refraction effects is proposed.This technique comprises a broad and narrow phase.In the broad phase,the water surface is considered flat.The vertices of underwater meshes are transformed based on Snell's Law.In the narrow phase,the effects of waves on the water surface are examined.Every pixel on the water surface mesh is collected by a screen-space method with an extra rendering pass.The broad phase redirects most pixels that need to be recalculated in the narrow phase to the pixels in the rendering buffer.Results We analyzed the performances of three different conventional methods and ours in rendering refraction effects for the same scenes.The proposed method obtains higher frame rate and physical accuracy comparing with other methods.It is used in several game scenes,and realistic water refraction effects can be generated efficiently.Conclusions The two-phase water refraction method produces a tradeoff between efficiency and quality.It is easy to implement in modern game engines,and thus improve the quality of rendering scenes in video games or other real-ti me applications.

Data-based real-time petrochemical gas diffusion simulation approach on virtual reality

Background Petrochemical products possess a high risk of flammability,explosivity,and toxicity,making petrochemical accidents exceedingly destructive.Therefore,disaster analysis,prediction,and real-time simulations have become important means of controlling and reducing accident hazards.Methods This study proposes a complete real-time simulation solution of gas diffusion with coordinate and concentration data,which was mainly aimed at simulating the types of harmful gas leakage and diffusion accidents in the petrochemical industry.The rendering effect was more continuous and accurate through grid homogenization and trilinear interpolation.This study presents a data processing and rendering parallelization process to enhance simulation efficiency.Gas concentration and fragment transparency were combined to synthesize transparent pixels in a scene.To ensure the approximate accuracy of the rendering effect,improve the efficiency of real-time rendering,and meet the requirement of intuitive perception using concentration data,a weighted blended order-independent transparency(OIT)with enhanced alpha weight is presented,which can provide a more intuitive perception of the hierarchical information of concentration data while preserving depth information.This study compares and analyzes three OIT algorithms-depth peeling,weighted blended OIT,and weighted blended OIT with enhanced alpha weight-in terms of rendering image quality,rendering time,required memory,and hierarchical information.Results Using weighted blended OIT with an enhanced alpha weight technique,the rendering time was shortened by 53.2%compared with that of the depth peeling algorithm,and the texture memory required was significantly smaller than that of the depth peeling algorithm.The rendering results of weighted blended OIT with an enhanced alpha weight were approximately accurate compared with those of the depth peeling algorithm as the ground truth,and there was no popping when surfaces passed through one another.Simultaneously,compared with weighted blended OIT,weighted blended OIT with an enhanced alpha weight achieved an intuitive perception of the hierarchical information of concentration data.

Power Consumption Optimization for 3D Graphics Rendering

This paper studies some programming techniques for low power rendering for 3 D graphics. These techniques are derived from analysis and simulation results of hardware circuits of GPU. Although low power3 D graphics hardware design has been studied by other researchers,low power programming techniques from hardware perspective have not been investigated in depth. There are many factors that affect 3 D graphics rendering performance,such as the number of vertices,vertex sharing,level of details,texture mapping,and rendering algorithms. An analytical study of graphics rendering workload is performed and the effect of a number of programming tips such as vertex sharing,clock gating and buffering of unmoving or translational objects is deeply studied. The results presented in this paper can be used to guide 3 D graphics programming for optimizing both power consumption and performance.

On-line Free-viewpoint Video:From Single to Multiple View Rendering

In recent years, many image-based rendering techniques have advanced from static to dynamic scenes and thus become video-based rendering （VBR） methods. But actually, only a few of them can render new views on-line. We present a new VBR system that creates new views of a live dynamic scene. This system provides high quality images and does not require any background subtraction. Our method follows a plane-sweep approach and reaches real-time rendering using consumer graphic hardware, graphics processing unit （GPU）. Only one computer is used for both acquisition and rendering. The video stream acquisition is performed by at least 3 webcams. We propose an additional video stream management that extends the number of webcams to 10 or more. These considerations make our system low-cost and hence accessible for everyone. We also present an adaptation of our plane-sweep method to create simultaneously multiple views of the scene in real-time. Our system is especially designed for stereovision using autostereoscopic displays. The new views are computed from 4 webcams connected to a computer and are compressed in order to be transfered to a mobile phone. Using GPU programming, our method provides up to 16 images of the scene in real-time. The use of both GPU and CPU makes this method work on only one consumer grade computer.

A Volume Rendering Algorithm for Sequential 2D Medical Images

Volume rendering of 3D data sets composed of sequential 2D medical images has become an important branch in image processing and computer graphics. To help physicians fully understand deep seated human organs and focuses ( e.g. a tumour) as 3D structures, in this paper, we present a modified volume rendering algorithm to render volumetric data. Using this method, the projection images of structures of interest from different viewing directions can be obtained satisfactorily. By rotating the light source and the observer eyepoint, this method avoids rotates the whole volumetric data in main memory and thus reduces computational complexity and rendering time. Experiments on CT images suggest that the proposed method is useful and efficient for rendering 3D data sets.

Fast interactive volume rendering method for adjustable vessel segmentation visualization

Medical diagnosis software and computer-assisted surgical systems often use segmented image data to help clinicians make decisions. The segmentation extracts the region of interest from the background, which makes the visualization clearer. However, no segmentation method can guarantee accurate results under all circumstances. As a result, the clinicians need a solution that enables them to check and validate the segmentation accuracy as well as displaying the segmented area without ambiguities. With the method presented in this paper, the real CT or MR image is displayed within the segmented region and the segmented boundaries can be expanded or contracted interactively. By this way, the clinicians are able to check and validate the segmentation visually and make more reliable decisions. After experiments with real data from a hospital, the presented method is proved to be suitable for efficiently detecting segmentation errors. The new algorithm uses new graphic processing uint （GPU） shading functions recently introduced in graphic cards and is fast enough to interact oil the segmented area, which was not possible with previous methods.

Real-time flow-based video abstraction using OpenCL

A non-photorealistic rendering technique is a method to show various effects different from those of realistic image generation.Of the various techniques,flow-based image abstraction displays the shape and color features well and performs a stylistic visual abstraction.But real-time rendering is impossible when CPU is used because it applies various filtering and iteration methods.In this paper,we present real-time processing methods of video abstraction using open open computing language(OpenCL),technique of general-purpose computing on graphics processing units(GPGPU).Through the acceleration of general-purpose computing(GPU),16 frame-per-second(FPS)or greater is shown to process video abstraction.

Partitioned k-Exclusion Real-Time Locking Protocol Motivated by Multicore Multi-GPU Systems

Graphic processing units （GPUs） have been widely recognized as cost-efficient co-processors with acceptable size, weight, and power consumption. However, adopting GPUs in real-time systems is still challenging, due to the lack in framework for real-time analysis. In order to guarantee real-time requirements while maintaining system utilization ~in modern heterogeneous systems, such as multicore multi-GPU systems, a novel suspension-based k-exclusion real-time locking protocol and the associated suspension-aware schedulability analysis are proposed. The proposed protocol provides a synchronization framework that enables multiple GPUs to be efficiently integrated in multicore real-time systems. Comparative evaluations show that the proposed methods improve upon the existing work in terms of schedulability.

基于WebGIS的大数据图形渲染技术

随着大气科学相关技术的高速发展,基于软件图形显示功能的更高展示要求在气象行业中被不断提出。人们在持续追求更加逼真视觉上的渲染效果:一方面保证稳定高效地渲染海量数据,另一方面,同时保证高质量图像文件的生成。为此,提出了一种针对海量气象数据的快速显示方案。通过有效压缩传输数据,并利用GPU显卡资源进行数据的渲染和数据的时间插值,能够有效提高数据显示渲染和交互的效率。实践应用表明,该方案能够较好地解决海量数据快速显示的问题,在针对气象大数据进行实时渲染动画播放之时,其播放展示速度可以高达30帧+(每秒),能够较好地满足实际业务需求。

基于通用处理器的图形软绘制引擎设计

机载图形绘制引擎是座舱显示设备的核心组成部分,针对部分机载座舱显示设备低成本、低功耗需求,提出了一种基于通用处理器的图形软绘制引擎实现方案,通过软件实现OpenGL渲染管线的功能,并在嵌入式硬件平台上进行了测试验证,结果证明了本方案的有效性和优越性。

Architecture of the Graphics System for Embedded Real-Time Operating Systems

This paper presents a new architecture of a graphics system for microkernel operating systems,including real-time operating systems.The following major parts of the architecture are presented:a user-level subsystem responsible for interaction with user applications;a bottom-level subsystem providing the functionality for graphics drivers,such as managing graphics output,video memory management,etc.;a kernel-level subsystem providing interaction with the kernel,and performing low-level operations,such as working with physical memory,processes,etc.The mechanisms of interaction of user applications with the user level of the graphics system,as well as interaction of the different levels of the graphics subsystem are presented.The paper pays much attention to various approaches to testing:the use of unit testing,testing using hardware and software emulators.Another important characteristic of a graphics system is its performance,in particular the performance of low-level operations such as memory allocation:the developed architecture suggests using a separate memory allocator which is faster than standard memory allocation functions.Comparison of the performances of graphics system implementation for microkernel real-time operating system and graphics server Xorg is presented,showing significant superiority of the proposed architecture in a number of work scenarios.

基于物理的蒙特卡罗体渲染综述

在计算机图形学中,渲染一直是核心方向,对于真实感渲染,其最终目标就是正确地计算场景中的全局光照。针对渲染对象的不同,所采取的渲染方法也有所不同,大体上可以分为表面渲染和体渲染。通过对物理的蒙特卡罗体渲染方法的整理,描述了在经典参与介质中如何采用蒙特卡罗方法进行渲染,介绍了近年来兴起的针对非经典参与介质的研究,对近年来渲染的高级方法做了总结,阐述了目前渲染方法所存在的问题以及未来可能的研究方向。

基于GPU的星载传感器光照反射三维可视化

为了能准确控制卫星在轨运行的姿态,避免太阳光及其反射光影响光学传感器工作,需要快速计算并绘制出不同时刻太阳光反射至传感器入瞳的光通量变化情况,设计并实现了一种基于图形处理器(GPU)的星载传感器光照反射分析算法,并对分析结果进行了实时三维可视化。首先以太阳为点光源,通过计算太阳位置矢量并利用深度图和渲染到纹理(RTT)技术,实时生成以太阳为视点的卫星表面受光区分析图;然后根据传感器反射镜面在卫星中的相对位置,计算出受光区范围内反射光线能够进入镜面的卫星部位,从而实现星载传感器反射区分析的三维可视化。实验结果表明,该算法具有较高的绘制效率和良好的视觉效果,对航天器光照环境的三维仿真具有一定的参考价值。

飞行仿真系统虚拟仪表关键技术探究

该文研究基于增强现实(AR)技术和图形渲染技术的飞行仿真虚拟仪表系统。利用实时光线追踪技术和高精度图像渲染算法,显著提升虚拟仪表的视觉真实感。结合AR技术,飞行员能够在仿真环境中实时获取动态调整的飞行信息,并通过手势识别和语音控制实现交互式操作。研究结果表明,AR与图形渲染技术的结合在提高飞行仿真系统的真实感、操作便捷性和安全性方面具有显著优势,为飞行训练和飞行器设计提供新的发展方向。

一种辅助“三维室内建模”实验教学的移动AR系统

在“三维室内建模”实验教学环节中,针对模型结构、纹理的繁杂多样以及学生三维空间感知能力不足等导致的实验教学质量低的问题,文章提出运用Unity3D引擎、AR Foundation开发平台和SenseAR XR Plugin插件开发一个辅助实验教学的Android移动端增强现实系统,登录后可对模型结构进行多视角观看,可以实时更换模型以及材质等,通过这种具有沉浸感的三维结构与可视化交互操作,提高学生的建模效率、三维空间感知能力以及创新设计能力。该研究为“三维建模”方向的实验教学提供了一种新的教学手段。

GPU芯片的图形渲染引擎设计及实现

在当前视觉呈现领域,提高极致渲染的效率与降低延迟成为该领域的核心挑战。分割帧渲染(Scissor Frame Rendering,SFR)技术虽能提升效率,但冗余计算与图形处理器(Graphics Processing Unit,GPU)间的顺序同步限制了其在多GPU环境下的程序扩展。本研究创新性地提出了针对多GPU系统的SFR优化方案,它利用图像合成并行性,通过精细任务分配与协同机制消除了传统性能障碍。优化GPU间的数据交换,减少等待时间,智能调度最大化计算资源利用,避免冗余计算。实验证明,新方案在多GPU环境下显著提升了性能与扩展性。当GPU数量增加时,渲染效率提升,延迟保持极低,有效验证了其在大规模并行渲染中的优势。