Controllable Image‐Based Transfer of Flow Phenomena

Modelling flow phenomena and their related weathering effects is often cumbersome due their dependence on the environment, materials and geometric properties of objects in the scene. Example‐based modelling provides many advantages for reproducing real textures, but little effort has been devoted to reproducing and transferring complex phenomena. In order to produce realistic flow effects, it is possible to take advantage of the widespread availability of flow images on the Internet, which can be used to gather key information about the flow. In this paper, we present a technique that allows the transfer of flow phenomena between photographs, adapting the flow to the target image and giving the user flexibility and control through specifically tailored parameters. This is done through two types of control curves: a fitted theoretical curve to control the mass of deposited material, and an extended colour map for properly adapting to the target appearance. In addition, our method filters and warps the input flow in order to account for the geometric details of the target surface. This leads to a fast and intuitive approach to easily transfer phenomena between images, providing a set of simple and intuitive parameters to control the process.     

顾及计算强度的地质矢量大数据计算域均衡分解方法研究

在地质大数据爆发式增长的背景下,本文结合目前在线大数据地图服务在实际应用中的瓶颈,针对面向地质大数据实时渲染的计算域均衡分解问题,研究了一系列的优化方案,包括矢量地图服务时间样本自动采集、矢量地图服务时间工时自动统计、矢量地图网格化、基于网格的可视域划分、多线程并行渲染,渲染结果合并等,在矢量大数据在线服务的响应速率提升方面获得了比较明显的效果。     

Turning a Digital Camera into an Absolute 2D Tele‐Colorimeter

We present a simple and effective technique for absolute colorimetric camera characterization, invariant to changes in exposure/aperture and scene irradiance, suitable in a wide range of applications including image‐based reflectance measurements, spectral pre‐filtering and spectral upsampling for rendering, to improve colour accuracy in high dynamic range imaging. Our method requires a limited number of acquisitions, an off‐the‐shelf target and a commonly available projector, used as a controllable light source, other than the reflected radiance to be known. The characterized camera can be effectively used as a 2D tele‐colorimeter, providing the user with an accurate estimate of the distribution of luminance and chromaticity in a scene, without requiring explicit knowledge of the incident lighting power spectra. We validate the approach by comparing our estimated absolute tristimulus values (XYZ data in ) with the measurements of a professional 2D tele‐colorimeter, for a set of scenes with complex geometry, spatially varying reflectance and light sources with very different spectral power distribution.     

Facile non-aqueous synthesis of high color rendering C@ZrSiO4 encapsulation pigment with carbon-containing precursors as in-situ carbon sources

A zircon encapsulated carbon black (C@ZrSiO₄) pigment with high color rendering was synthesized via facile non-aqueous acetic acid (NAA) assisted sol-gel method using carbon-containing precursors (zirconium n-propoxide and tetraethoxysilane) as in-situ carbon sources. The effects of the NAA amount and heat treatment temperature on the structure and properties of the synthesized encapsulation pigments were characterized by XRD, FT-IR, FE-SEM, HR-TEM, EDS, XPS and CIELAB colorimeter, respectively. The results showed that the C@ZrSiO₄ encapsulated pigments heating at 1000?°C for 2?h in N₂ atmosphere presented a dense and stable encapsulation structure as well as deep dark hue when the mole ratio of NAA and Zr (NAA/Zr) was 3:1, and the chromaticity values were L*?= 21.20, a*?= 0.56, b*?= ?0.09 and C_ab =?0.57, respectively, which were contributed to the high homogeneity at atomic level in ZrSiO₄ sol and the tight bonding between carbon black carbonized by carbon containing group and zircon matrix. In addition, the pigment exhibited excellent chemical stability, thermal stability and tinctorial strength when it was used in water, acid, alkali, organic solvents and ceramic glaze. Especially, these pigments improved the utilization of raw materials and avoided the use of heavy metals or transition metals as coloring agent, which was an environment-friendly black ceramic pigment.     

体绘制技术在煤田地震数据可视化中的应用

分析了地震数据特点 ,并根据地质分析的特殊需要对原有光线投射体绘制算法进行简化和改进 ,从而大幅度提高了重构速度。论文利用VC 及OpenGL在微机上实现了对地震勘探的大规模三维规则网格数据的可视化处理 ,取得了较好的效果     

建筑节能材料检测中的几点问题与探讨

本文针对检测过程中出现的一些问题,从试样制备、胶粘剂和抹面胶浆、现场锚栓拉拔以及导热系数四个方面进行了分析,提出了自己的观点和解决问题的建议.     

MEMBRANE BIOREACTORS AND CONSTRUCTED WETLANDS FOR TREATMENT OF RENDERING PLANT WASTEWATER

The performance of a novel industrial membrane bioreactor (MBR) comprising denitrification, nitrification and ultrafiltration for the secondary treatment of primary treated animal rendering wastewater has been compared with an experimental, low-cost and novel vertical-flow constructed wetland planted with Typha latifolia L. (Reedmace or Broad-leaved Cattail). The process wastewater followed pre-treatment by dissolved air flotation (DAF). The mean DAF effluent gave highly variable chemical oxygen demand (COD) and ammonia concentrations of 5816 (standard deviation (SD): 3005.0) and 614 (SD: 268.7) mg/l, respectively. The mean MBR effluent for COD and ammonia was 37 and 86 mg/l, respectively. The mean treatment performance of the constructed wetland for COD, ammonia and suspended solids was 205, 67 and 57 mg/l, respectively.     

基于GIS和体视化技术的工程场地地震液化势3D可视化

工程场地地震液化势三维模型的建立及可视化研究的目的是用三维图形来描述地震动作用下场地液化势的空间分布特性,以此为城市防震减灾工作提供相应的支持。采用具有概率意义的饱和砂土抗液化强度经验公式来对场地进行地震液化势概率评价;采用一种基于"块"模型的数据结构来描述场地液化势三维实体;结合Kriging插值法和体视化技术进行场地液化势的三维可视化建模。研究表明:采用"块"数据模型来分割模拟三维液化势场,利用Kriging法对工程场地地震液化势进行空间数据三维插值,有助于揭示勘探孔以外任意空间点的土层液化势信息;基于液化势概率评价结果和体视化技术,采用Kriging插值法,以不同的色标体现场地液化势的风险程度,可以直观的三维图像形式呈现场地液化势的空间分布特性和变化趋势,通过剖切自动生成指定位置的二维剖面和三维切割体,工程场地液化势的三维分布特性得到有效的表达。     

移动在线实时绘制技术研究综述

移动在线实时绘制技术受移动互联网发展的驱动,为3维可视化、计算机视觉、虚拟现实、增强现实、扩展现实和元宇宙等新兴研究领域提供了核心技术的支撑。本文以在线实时绘制技术为切入点,探讨了该技术在移动端、Web端、云端和多端协同这4类平台下的发展重心和研究现状,并深度阐述了工业级在线云平台的实施方案。首先,针对移动端的在线实时绘制,分析了近年来移动端绘制硬件构架设计的优化方向;探讨了在功耗和带宽受到制约的情况下移动端如何对渲染算法进行加速,如何对高功耗的光线跟踪算法进行优化;列举了包括图形应用程序编程接口(application programming interface,API)和游戏引擎在内的移动端渲染工具。然后,针对Web端在线实时绘制,分析了Web端的3D渲染机制,梳理了以3D场景的轻量化预处理、大规模3D场景的细粒度化网络传输、3D场景的对等传输以及Web3D在线特效渲染为代表的Web端在线绘制的关键技术(尤其面向大规模3D场景),列举了国内外知名Web3D引擎并探讨了主流游戏引擎对Web3D应用的支持。再后,针对云端在线实时绘制,从应用托管、资源调度和串流这三大云平台的核心功能入手,调研了以串流应用优化技术为核心的在线云绘制现状。此后,从多端绘制任务分摊机制入手,分析了以“端云”协同和“端边云”协同为目标的在线多端协同绘制的发展。最后,以当前工业级在线云绘制平台为研究对象,分析了包括微软、英伟达、Unity、酷家乐等一线云绘制企业的在线实时云绘制平台方案,验证了移动在线绘制技术在工业界的实用性。     

真实数据驱动下的变电站三维智能仿真技术研究

随着大数据技术的发展,面向变电站三维虚拟场景,考虑变电站三维仿真模型的准确性和仿真环境的真实性,融合色彩、声音、图像等真实数据高效模拟变电站的各种操作和设备拆装。从数据层、系统设计层、功能应用层等3方面详细分析了变电站多维多媒体仿真系统架构,以变压器为例分析了变电站主设备结构建模与精准拆装设计流程,最后引入顶点纹理技术,考虑变电站不同运行状态下的动态色差,融合变电站真实数据驱动,实现动态色彩渲染与声效模拟。基于主场景漫游、GIS漏气与主设备着火等事故示例验证本文仿真渲染技术的有效性。