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.

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.

Towards Cache-Assisted Hierarchical Detection for Real-Time Health Data Monitoring in IoHT

Real-time health data monitoring is pivotal for bolstering road services’safety,intelligence,and efficiency within the Internet of Health Things(IoHT)framework.Yet,delays in data retrieval can markedly hinder the efficacy of big data awareness detection systems.We advocate for a collaborative caching approach involving edge devices and cloud networks to combat this.This strategy is devised to streamline the data retrieval path,subsequently diminishing network strain.Crafting an adept cache processing scheme poses its own set of challenges,especially given the transient nature of monitoring data and the imperative for swift data transmission,intertwined with resource allocation tactics.This paper unveils a novel mobile healthcare solution that harnesses the power of our collaborative caching approach,facilitating nuanced health monitoring via edge devices.The system capitalizes on cloud computing for intricate health data analytics,especially in pinpointing health anomalies.Given the dynamic locational shifts and possible connection disruptions,we have architected a hierarchical detection system,particularly during crises.This system caches data efficiently and incorporates a detection utility to assess data freshness and potential lag in response times.Furthermore,we introduce the Cache-Assisted Real-Time Detection(CARD)model,crafted to optimize utility.Addressing the inherent complexity of the NP-hard CARD model,we have championed a greedy algorithm as a solution.Simulations reveal that our collaborative caching technique markedly elevates the Cache Hit Ratio(CHR)and data freshness,outshining its contemporaneous benchmark algorithms.The empirical results underscore the strength and efficiency of our innovative IoHT-based health monitoring solution.To encapsulate,this paper tackles the nuances of real-time health data monitoring in the IoHT landscape,presenting a joint edge-cloud caching strategy paired with a hierarchical detection system.Our methodology yields enhanced cache efficiency and data freshness.The corroborative numerical data accentuates the feasibility and relevance of our model,casting a beacon for the future trajectory of real-time health data monitoring systems.

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.

A Tiny Example Based Procedural Model for Real-Time Glinty Appearance Rendering

The glinty details from complex microstructures significantly enhance rendering realism.However,the previous methods use high-resolution normal maps to define each micro-geometry,which requires huge memory overhead.This paper observes that many self-similarity materials have independent structural characteristics,which we define as tiny example microstructures.We propose a procedural model to represent microstructures implicitly by performing spatial transformations and spatial distribution on tiny examples.Furthermore,we precompute normal distribution functions(NDFs)by 4D Gaussians for tiny examples and store them in multi-scale NDF maps.Combined with a tiny example based NDF evaluation method,complex glinty surfaces can be rendered simply by texture sampling.The experimental results show that our tiny example based the microstructure rendering method is GPU-friendly,successfully reproducing high-frequency reflection features of different microstructures in real time with low memory and computational overhead.

RenderKernel:High-level programming for real-time rendering systems

Real-time rendering applications leverage heterogeneous computing to optimize performance.However,software development across multiple devices presents challenges,including data layout inconsistencies,synchronization issues,resource management complexities,and architectural disparities.Additionally,the creation of such systems requires verbose and unsafe programming models.Recent developments in domain-specific and unified shading languages aim to mitigate these issues.Yet,current programming models primarily address data layout consistency,neglecting other persistent challenges.In this paper,we introduce RenderKernel,a programming model designed to simplify the development of real-time rendering systems.Recognizing the need for a high-level approach,RenderKernel addresses the specific challenges of real-time rendering,enabling development on heterogeneous systems as if they were homogeneous.This model allows for early detection and prevention of errors due to system heterogeneity at compile-time.Furthermore,RenderKernel enables the use of common programming patterns from homogeneous environments,freeing developers from the complexities of underlying heterogeneous systems.Developers can focus on coding unique application features,thereby enhancing productivity and reducing the cognitive load associated with real-time rendering system development.

Inter-laboratory Validation of Real-time PCR Assays for Goat-,Horse-and Donkey-derived Material in Meat Products

In this study,we performed an inter-laboratory collaborative ring trial to develop and validate specific TaqMan real-time PCR assays for goat-,horse-,and donkey-derived material in meat products.The performances of these assays in different environments and situations were comprehensively evaluated.This ring trial involved the participation of 12 laboratories in Europe and Asia.The results from the participating laboratories were analyzed to determine the specificity,accuracy,false positive rate,limit of detection(LOD),and probability of detection(POD)of the developed assays.Statistical analysis showed that the false positive and negative rates were zero,the LOD was five copies/reaction,and the laboratory standard deviation(σ_(L))was 0.30 for all three assays.Thus,the results demonstrate that the developed methods are robust and suitable for the detection and identification of goat-,horse-,and donkey-derived materials in meat products.

BIM云渲染平台建设及其应用研究

本文介绍了一种基于云原生环境的BIM可视化平台建设手段、关键技术及其应用方向,创新性地以云渲染技术手段解决了传统BIM可视化过程的若干痛点,并实现了高效、高质的BIM模型渲染。本文研究的云渲染平台以提供SaaS化的BIM服务为目标,在建设探索的过程中解决了诸如多源异构模型转换、大模型渲染优化以及高并发等众多技术难点,并摸索出了一套成熟可用的BIM云渲染平台建设方法。同时,在平台的应用推广上,结合BIM做了一系列应用探索,并对当前技术条件下云渲染在BIM可视化方向的发展前景做了客观分析和展望。

Real-time rendering of layered materials with anisotropic normal distributions

This paper proposes a lightweight bidirectional scattering distribution function(BSDF)model for layered materials with anisotropic reflection and refraction properties.In our method,each layer of the materials can be described by a microfacet BSDF using an anisotropic normal distribution function(NDF).Furthermore,the NDFs of layers can be defined on tangent vector fields,which differ from layer to layer.Our method is based on a previous study in which isotropic BSDFs are approximated by projecting them onto base planes.However,the adequateness of this previous work has not been well investigated for anisotropic BSDFs.In this paper,we demonstrate that the projection is also applicable to anisotropic BSDFs and that the BSDFs are approximated by elliptical distributions using covariance matrices.

Development of a multi-view and geo-event-driven real-time collaborative GIS

Supporting distributed real-time collaborative work has become an important development trend in GIS.It enables group users to cooperate and improve the use of scientific data and collaboration technologies.Real-time collaborative GIS(RCGIS)provides a platform for supporting synchronous collaboration using geospatial data in various forms.Traditional RCGIS generally works on a single map view,which has the disadvantage of collaborative interface confusion.The traditional system-driven mechanism of RCGIS is a computer-interaction event that has the disadvantage of an unfriendly collaborative perception.This paper presents a design and prototype of a RCGIS based on multi-view and geo-event driven mechanisms.The geo-event-driven mechanism provides users with a smoother collaborative perception and interactions that are more natural and friendly.The collaboration process for a GIS that is driven by geo-events is also discussed.A multi-view technique is used to make real-time GIS collaboration more orderly.The paper also proposes a synchronization strategy for public–private views.Finally,walk-through examples are used to demonstrate the use of RCGIS within a web environment.

A Fast Ambient Occlusion Method for Real-Time Plant Rendering

Global illumination effects are crucial for virtual plant rendering. Whereas real-time global illumination rendering of plants is impractical, ambient occlusion is an efficient alternative approximation. A tree model with millions of triangles is common, and the triangles can be considered as randomly distributed. The existing ambient occlusion methods fail to apply on such a type of object. In this paper, we present a new ambient occlusion method dedicated to real time plant rendering with limited user interaction. This method is a three-step ambient occlusion calculation framework which is suitable for a huge number of geometry objects distributed randomly in space. The complexity of the proposed algorithm is O（n）, compared to the conventional methods with complexities of O（n^2）. Furthermore, parameters in this method can be easily adjusted to achieve flexible ambient occlusion effects. With this ambient occlusion calculation method, we can manipulate plant models with millions of organs, as well as geometry objects with large number of randomly distributed components with affordable time, and with perceptual quality comparable to the previous ambient occlusion methods.

Domino Tiling:A New Method of Real-Time Conforming Mesh Construction for Rendering Changeable Height Fields

In this paper we present a novel GPU-oriented method of creating an inherently continuous triangular mesh for tile-based rendering of regular height fields. The method is based on tiling data-independent semi-regular meshes of non-uniform structure, a technique that is quite different from other mesh tiling approaches. A complete, memory efficient set of mesh patterns is created by an off-line procedure and stored into the graphics adapter＇s memory at runtime. At rendering time, for each tile, one of the precomputed mesh patterns is selected for rendering. The selected mesh pattern fits the required level of details of the tile and ensures seamless connection with other adjacent mesh patterns, like in a game of dominoes. The scalability potential of the proposed method is demonstrated through quadtree hierarchical grouping of tiles. The efficiency is verified by experimental results on height fields for terrain representation, where the method achieves high frame rates and sustained triangle throughput on high resolution viewports with sub-pixel error tolerance. Frame rate sensitivity to real-time modifications of the height field is measured, and it is shown that the method is very tolerant and consequently well tailored for applications dealing with rapidly changeable phenomena represented by height fields.

Epoch-based Application Collaboration for Sensing Data Analysis

The application collaboration was addressed to provide energy-efficient data services for distributed sensing applications to collaboratively interacting to achieve a desired global objective not detectable by any single cluster. An epoch-based transaction model was proposed by using the concept of sphere of control （SoC）, and a collaborative sensing application can be dynamically formed as a nested architecture composed of time-synchronized applications. By loosening the rigid constraints of ACID to adapt the requirements of sensor networks, the submission, rollback and consistency rules ware educed and a two-phrase submission protocol was designed. Finally, it was illustrated that the model is capable of providing an adaptive formal template for sensing application collaboration. Our performance evaluations show that by applying the two-phrase submission protocol, we can significantly improve the number of reported answers and response time, raise resource utilization, and reduce the energy cansumption and data loss.

Foveated rendering:A state-of-the-art survey

Recently,virtual reality(VR)technology has been widely used in medical,military,manufacturing,entertainment,and other fields.These applications must simulate different complex material surfaces,various dynamic objects,and complex physical phenomena,increasing the complexity of VR scenes.Current computing devices cannot efficiently render these complex scenes in real time,and delayed rendering makes the content observed by the user inconsistent with the user’s interaction,causing discomfort.Foveated rendering is a promising technique that can accelerate rendering.It takes advantage of human eyes’inherent features and renders different regions with different qualities without sacrificing perceived visual quality.Foveated rendering research has a history of 31 years and is mainly focused on solving the following three problems.The first is to apply perceptual models of the human visual system into foveated rendering.The second is to render the image with different qualities according to foveation principles.The third is to integrate foveated rendering into existing rendering paradigms to improve rendering performance.In this survey,we review foveated rendering research from 1990 to 2021.We first revisit the visual perceptual models related to foveated rendering.Subsequently,we propose a new foveated rendering taxonomy and then classify and review the research on this basis.Finally,we discuss potential opportunities and open questions in the foveated rendering field.We anticipate that this survey will provide new researchers with a high-level overview of the state-of-the-art in this field,furnish experts with up-to-date information,and offer ideas alongside a framework to VR display software and hardware designers and engineers.

虚拟环境下的低延迟协同渲染方法研究

虚拟现实技术以其独特的沉浸感、交互性,在游戏、直播等各领域的应用愈加广泛。渲染技术是虚拟现实的核心环节之一,而只在本地客户端渲染是目前主要渲染方案,由于实时渲染需要大量的计算资源,导致虚拟现实应用存在响应延迟高、画面刷新率低、图像质量差以及虚拟场景复杂等问题。针对上述问题,该文提出了虚拟环境下低延迟协同渲染方法。首先,将复杂的虚拟环境进行前景交互和背景环境拆分;其次,将渲染工作量较大的背景环境卸载至服务端进行处理;最后,通过运动轨迹预测将渲染的复杂背景以全景图的方式进行分割编码传输至客户端与前景渲染的内容进行合并呈现。经过实验验证,这种协同渲染的方法能够进一步降低传输过程中的CPU/GPU利用率以及网络延迟,提高帧刷新率,进而实现高清低延迟交互。

A New Generation of Intelligent Mapping and Remote Sensing Scientific Test Satellite Luojia-301

With the continuous improvement of the performance and the increasing variety of optical mapping and remote sensing satellites,they have become an important support for obtaining global accurate surveying and mapping remote sensing information.At present,optical mapping and remote sensing satellites already have sub-meter spatial resolution capabilities,but there is a serious lag problem in mapping and remote sensing information services.It is urgent to develop intelligent mapping and remote sensing satellites to promote the transformation and upgrading to real-time intelligent services.Firstly,based on the three imaging systems of the optical mapping and remote sensing satellites and their realization methods and application characteristics,this paper analyzes the applicable system of the intelligent mapping and remote sensing satellites.Further,according to the application requirements of real-time,intelligence,and popularization,puts forward the design concept of integrated intelligent remote sensing satellite integrating communication,navigation,and remote sensing and focuses on the service mode and integrated function composition of intelligent remote sensing satellite.Then expounds on the performance and characteristics of the Luojia-301 satellite,a new generation of intelligent surveying and mapping remote sensing scientific test satellite.And finally summarizes and prospects the development and mission of intelligent mapping remote sensing satellites.Luojia-301 satellite integrates remote sensing and communication functions.It explores an efficient and intelligent service mode of mapping and remote sensing information from data acquisition to the application terminal and provides a real service verification platform for on-orbit processing and real-time transmission of remote sensing data based on space-ground internet,which is of great significance to the construction of China’s spatial information network.

一种协同渲染环境下的场景管理策略

随着计算机图形学和虚拟现实技术的发展,场景的实时渲染逐步成为计算机图形学中一个令人关注的重要问题,而各种高沉浸感虚拟现实环境的出现使得多场景的协同实时渲染成为必要。因此,为实现多场景的协同实时渲染,提出并实现了一个协同渲染环境,并对其中采用的场景管理技术进行研究,采用八叉树和场景树相结合的方法对场景中的静态和动态实体分别进行管理,以此为基础,实施了场景管理与绘制相分离的策略。实践证明,利用这种场景管理的思想,结合通信机制,能实现多场景间的协同实时渲染,从而验证了这种场景管理思想的有效性。