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 onli...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.展开更多
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,...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.展开更多
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 obj...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.展开更多
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,refractio...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.展开更多
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 ha...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.展开更多
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 ...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.展开更多
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 ...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.展开更多
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 ...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.展开更多
A real-time,long-term surface meteorological blended forcing dataset(SMBFD)has been developed based on station observations,satellite retrievals,and reanalysis products in China.The observations are collected at natio...A real-time,long-term surface meteorological blended forcing dataset(SMBFD)has been developed based on station observations,satellite retrievals,and reanalysis products in China.The observations are collected at national and regional automatic weather stations,satellite data are obtained from the Fengyun(FY)series satellites retrievals,and the reanalysis products are obtained from the ECMWF.The 90-m resolution digital terrain elevation data in China are obtained from the Shuttle Radar Topographic Mission(SRTM)for temperature and humidity elevation adjustment.The dataset includes 2-m air temperature and humidity,10-m zonal and meridional winds,downward shortwave radiation,surface pressure,and precipitation.The spatial resolution is 1 km,and the temporal resolution is 1 h.During the data processing procedure,various data fusion techniques including the space–time multiscale variational analysis,the discrete ordinates radiative transfer(DISORT)model,the hybrid radiation estimation model,and a terrain correction algorithm are employed.Dependent and independent evaluations of the dataset are performed against observations.The SMBFD dataset is also compared with similar datasets produced in other major meteorological operational centers in the world.The results are as follows.(1)All variables show reasonable geographic distribution features and realistic spatial and temporal variations.(2)Dependent and independent evaluations both indicate that the gridded SMBFD dataset is close to the observations,while the dependent evaluation yields better results than the independent evaluation.(3)Compared with similar datasets produced in other meteorological operational centers,the real-time and retrospective surface meteorological fusion data obviously have higher quality.The dataset introduced in the present study is in general stable and accurate,and can be applied in various practice such as meteorology,agriculture,ecology,environmental protection,etc.Meanwhile,this dataset has been used as the atmospheric forcing data to drive the operational High-resolution Land Data Assimilation System of China Meteorological Administration.The dataset with the network Common Data Form(NETCDF)can be decoded by various programming languages,and it is freely available to non-commercial users.展开更多
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...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.展开更多
We present algorithms that allow for reat-time rendering of 3D-scenes with a watercolor painting appearance,Our approach provides an appropriate simplification of the visual complexity,initates characteristic natural ...We present algorithms that allow for reat-time rendering of 3D-scenes with a watercolor painting appearance,Our approach provides an appropriate simplification of the visual complexity,initates characteristic natural effects of watercolor,and provides two essential painting techniques,the wet-on-wet and the wet-on-dry painting.We concentrate on efficient algorithms based on image space processing rather than on an exact simulation.This allows for the real-time rendering of 3D-scenes.During an animation a high frame-to-frame coherence can be achieved due to a stable segmentation scheme.Finally,we seamlessly integrate a smooth illumination into the watercolor renderings nsing information from the 3D-scenc.展开更多
The reflection of a bright light source on a dynamic surface such as water with waves can be difficult to render well in real time due to reflection aliasing and flickering.In this paper,we propose a solution to this ...The reflection of a bright light source on a dynamic surface such as water with waves can be difficult to render well in real time due to reflection aliasing and flickering.In this paper,we propose a solution to this problem by approximating the reflection direction distribution for the water surface as an elliptical Gaussian distribution.Then we analytically integrate the reflection contribution throughout the rendering interval time.Our method can render in real time an animation of the time integrated reflection of a spherical light source on highly dynamic waves with reduced aliasing and flickering.展开更多
基金the Science and Technology Program of Educational Commission of Jiangxi Province,China(DA202104172)the Innovation and Entrepreneurship Course Program of Nanchang Hangkong University(KCPY1910)the Teaching Reform Research Program of Nanchang Hangkong University(JY21040).
文摘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.
基金Supported by National Natural Science Foundation of China(Nos.6117020561472010 and 61421062)+2 种基金National Key Technology Support Program(No.2013BAK03B07)National Key Technology R&D Program(2015BAK01B06)Shenzhen Gov Projects(JCYJ20130331144416448)
文摘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.
基金supported by the National Natural Science Foundation of China(No.61102167)
文摘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.
基金the Fundamental Research Funds for the Central Universities,the National Key R&D Program of China(2018 YFB 1403900)the High-quality and Cutting-edge Disciplines Construction Project for Universities in Beijing(Internet Information,Communication University of China).
文摘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.
基金Supported by National Key R&D Program of China (2020YFB1710400)。
文摘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.
基金supported by the JST ACCEL(JPMJAC1602)JSPS KAKENHI(JP17H06101,18K18075,and JP19H01129).
文摘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.
基金This work is supported by the National Natural Science Foundation of China(Grant Nos.60073007 and 60473110)National High Technology Development 863 Program of China(Grant No.2006AA01Z301)LIAMA,and French National Research Agency(Grant No.NATSIM ANR-05-MMSA-45).
文摘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.
基金supported by the projects TR32039 and TR32047 of the Ministry of Science and Technological Development of Serbia
文摘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.
基金Supported by the National Key Research and Development Program of China(2018YFC1506601)National Natural Science Foundation of China(91437220)China Meteorological Administration Special Public Welfare Research Fund(GYHY201306045 and GYHY201506002).
文摘A real-time,long-term surface meteorological blended forcing dataset(SMBFD)has been developed based on station observations,satellite retrievals,and reanalysis products in China.The observations are collected at national and regional automatic weather stations,satellite data are obtained from the Fengyun(FY)series satellites retrievals,and the reanalysis products are obtained from the ECMWF.The 90-m resolution digital terrain elevation data in China are obtained from the Shuttle Radar Topographic Mission(SRTM)for temperature and humidity elevation adjustment.The dataset includes 2-m air temperature and humidity,10-m zonal and meridional winds,downward shortwave radiation,surface pressure,and precipitation.The spatial resolution is 1 km,and the temporal resolution is 1 h.During the data processing procedure,various data fusion techniques including the space–time multiscale variational analysis,the discrete ordinates radiative transfer(DISORT)model,the hybrid radiation estimation model,and a terrain correction algorithm are employed.Dependent and independent evaluations of the dataset are performed against observations.The SMBFD dataset is also compared with similar datasets produced in other major meteorological operational centers in the world.The results are as follows.(1)All variables show reasonable geographic distribution features and realistic spatial and temporal variations.(2)Dependent and independent evaluations both indicate that the gridded SMBFD dataset is close to the observations,while the dependent evaluation yields better results than the independent evaluation.(3)Compared with similar datasets produced in other meteorological operational centers,the real-time and retrospective surface meteorological fusion data obviously have higher quality.The dataset introduced in the present study is in general stable and accurate,and can be applied in various practice such as meteorology,agriculture,ecology,environmental protection,etc.Meanwhile,this dataset has been used as the atmospheric forcing data to drive the operational High-resolution Land Data Assimilation System of China Meteorological Administration.The dataset with the network Common Data Form(NETCDF)can be decoded by various programming languages,and it is freely available to non-commercial users.
基金supported by National Key R&D Program of China(2019YFC1521102)the National Natural Science Foundation of China(61932003)Beijing Science and Technology Plan(Z221100007722004).
文摘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.
文摘We present algorithms that allow for reat-time rendering of 3D-scenes with a watercolor painting appearance,Our approach provides an appropriate simplification of the visual complexity,initates characteristic natural effects of watercolor,and provides two essential painting techniques,the wet-on-wet and the wet-on-dry painting.We concentrate on efficient algorithms based on image space processing rather than on an exact simulation.This allows for the real-time rendering of 3D-scenes.During an animation a high frame-to-frame coherence can be achieved due to a stable segmentation scheme.Finally,we seamlessly integrate a smooth illumination into the watercolor renderings nsing information from the 3D-scenc.
基金supported by JSPS KAKENHI Grant Nos.JP15H05924,JP18H03348,and JP20H05954.
文摘The reflection of a bright light source on a dynamic surface such as water with waves can be difficult to render well in real time due to reflection aliasing and flickering.In this paper,we propose a solution to this problem by approximating the reflection direction distribution for the water surface as an elliptical Gaussian distribution.Then we analytically integrate the reflection contribution throughout the rendering interval time.Our method can render in real time an animation of the time integrated reflection of a spherical light source on highly dynamic waves with reduced aliasing and flickering.