漳浦县石寨窑发掘简报

漳浦县石寨窑址是闽南一处专门仿烧龙泉青瓷的窑场,从元代开始,一直延续到明初。其产品种类较少,釉色比较丰富。窑业技术颇具特色,出现了介于分室龙窑和横室阶级窑之间的窑炉结构,对研究闽南地区横室阶级窑的起源与发展具有重要意义

浦城县大口窑调查勘探报告

浦城县大口窑是宋元时期闽北地区一处著名的窑场,以烧造青白瓷为主,此外还兼烧部分酱釉瓷、少量绿釉瓷等。器型种类丰富,质量较高,窑业技术与江西景德镇窑关系密切。其产品在东亚、东南亚等地有发现,是福建一处重要的外销瓷生产地

光学成像效果真实感绘制技术研究

光学成像效果是与光学镜头成像特性相关的一类光学效果，常见的包括景深、渐晕、光学像差、散景、眩光等效果，在计算机生成的图像中加入这些效果可以增强图像的真实感和逼真度。本文的研究工作主要致力于解决在计算机合成图像中加入复杂的真实感的光学成像效果这一问题，以增强图像的真实感和逼真度。具体工作包括：1）针对现有光学镜头模型精度不高的问题，提出一个更加精确的光学镜头模型。该模型通过建立镜头表面模型和色散模型，以对各种复杂的物理镜头进行精确建模，再结合镜头内的光线追踪模型，即可对物理镜头的各种光学成像特性进行精确模拟。为了增强模型的实用性，结合镜头设计原理和摄影原理，提出多个镜头光学特性模型以控制模型的光学成像性能，并引入一个或多个相应的镜头参数以控制每个镜头特性，因而使用者无需掌握太多与镜头相关的光学知识，即可通过调节该模型的参数完成各种光学成像效果的模拟。2）针对现有方法绘制的散景效果真实感较差的问题，提出一种基于光阑的散景效果真实感绘制方法。该方法以光线传播的折射定律为基础，利用序列光线追踪方法对光学镜头的光学成像特性进行精确建模；对光学镜头的内部结构进行精确模拟，包括孔径光阑和渐晕光阑，以绘制出由孔径形状和渐晕共同作用的散景效果；利用几何光学理论和序列光线追踪方法精确计算出出射光瞳的位置和大小，以辅助光线采样，提高光线追踪效率。3）提出一种基于单色像差的散景效果真实感绘制方法，该方法基于真实感的光学镜头模型和分布式光线追踪算法。首先从光学理论上对散景和光学像差的关系进行了分析，包括四种像差，即球差、慧差、像散和场曲。在此基础上，引入一个基于物理的光学镜头模型以精确建模光学像差，该模型以详细的镜头描述作为输入。利用镜头内的光线追踪算法计算出入射光瞳和出射光瞳的的位置和直径，以实现高效的光线采样。为了与双向光线追踪算法进行集成，提出了一种通用的序列光线追踪算法。4）提出一种基于色差的散景效果真实感绘制方法，该方法采用精确的光谱光学镜头模型和高效的光谱绘制技术。首先从光学理论上分析复杂物理镜头的色差对散景效果的影响；在此基础上，引入一个精确的光谱镜头模型以精确建模镜头色差，同时提出一种镜头内的色散光线追踪算法，以与双向光线追踪算法进行集成；提出一种简单高效的光谱采样技术以支持镜头色散的建模，同时对双向光线追踪算进行改进以集成所提的光谱镜头模型。5）提出一种新方法以精确模拟不同视觉条件下的人眼视觉图像，该方法采用一个精确的人眼模型，以模拟人眼的解剖学和光学特性；该模型包括Navarro示意眼模型和相应的调节模型组成，这两个模型共同用于模拟人眼可变的折射能力；最后的绘制实验利用分布式光线追踪技术合成出多种真实感的人眼视觉效果。As optical effects caused by physical lenses, optical imaging effects are various, including depth of field, bokeh, optical aberration, vignetting and glare. Accurate simulating of these effects can improve the realism and fidelity of the rendered images. This dissertation focuses on simulating optical imaging effects in the computer-synthesized images to enhance their realism and fidelity. It includes the following topics:1) Motivated by inaccuracy of existing camera lens models, an accurate lens model is proposed. This model employs lens surface modeling to accurately model the geometry of complex physical lenses, and combines dispersion modeling and ray tracing techniques inside this model to accurately simulate the optical properties of physical lenses. To improve the practicability of this novel model, multiple optical models are presented, according to lens design and photograph principles, to control its optical lens properties, and corresponding parameters are introduced to control each lens property. As a consequence, users can simulate complex lens-related effects by tuning these lens parameters without too much expertise on lens optics.2) Based on geometrical optics theory, a new method for realistic rendering of bokeh effect is proposed to improve poor rendering quality of existing methods. A sequential ray tracing method, based on refraction law for transporting light, is employed to accurately model optical imaging characteristics of a camera lens; the internal structure of a camera lens is precisely simulated, including aperture stop and vignetting stop, in order to simulate bokeh effect affected by both aperture shape and vignetting; Based on geometrical optics theory and sequential ray tracing method, position and size of exit pupil in a camera lens are calculated and used for helping ray sampling and advancing efficiency of ray tracing.3) A novel realistic bokeh rendering method, based on an accurate camera lens model and distributed ray tracing, is presented. An optical analysis of the relationship between bokeh and optical aberrations, including spherical aberration, coma, astigmatism and field curvature, is firstly introduced. Based on this analysis, a physically-based camera lens model, which takes detailed lens prescription as input, is then introduced for accurately modeling the aberrations. The position and diameter of the entrance and exit pupils are calculated by tracing rays inside the lens for achieving efficient ray sampling, and a general sequential ray tracing algorithm is proposed to better combine with bidirectional ray tracing. Furthermore, correct integration between the lens model and bidirectional ray tracing is also analyzed.4) A novel realistic bokeh rendering method, based on an accurate spectral lens model and an efficient spectral rendering approach, is proposed. A concise optical analysis is firstly introduced on how bokeh appearance is influenced by chromatic aberrations of complex physical lenses. A physically-based spectral lens model, which takes real lens prescription as input, is then introduced for accurately modeling the chromatic aberrations, and a sequential dispersive ray tracing algorithm inside the lens is proposed to better join with bidirectional ray tracing. A new spectral rendering scheme is introduced to accelerate rendering of lens dispersion and support integration between the lens model and bidirectional ray tracing.5) A novel method is proposed to accurately simulate the human vision under different visual perception. This method introduces an accurate eye model to reasonably predict the anatomical and optical properties of the human eye. This eye model is composed of the Navarro schematic eye model with aspherical surfaces as a basic model, and a corresponding accommodation model, which are combined to simulate the varying refractive power of the human eye. Distributed ray tracing technique is combined with this eye model to produce a variety of visual results

A microfacet-based physically rendering of diffraction effects

针对当前光子衍射效果绘制方法的真实感问题,提出应用微表面模型的衍射效果物理绘制方法.该方法融合了现有衍射绘制模型中的特点,并结合特定材质的可变菲 涅尔系数来增强衍射效果;通过综合考虑微表面对光子的吸收、遮挡、再反射等交互场景,扩展了高度场微表面的适用范围;引入维格纳分布函数推迟衍射效果,以 进一步增强微表面模型;利用蒙特卡罗采样理论求解波动方程积分式以降低计算复杂度,辅以几何光线追踪理论,求取微表面辐射度空间分布;最终以光的波动方程 为基础,构建了可应用于光线追踪器的双向反射分布函数衍射光学模型.实验结果表明,该模型能够有效地模拟波的相位与幅值信息,可绘制出较为逼真的衍射效果 .To address the problem of realistically rendering diffraction effects in computer graphics, this paper proposes a physically rendering method based on the microfacet diffraction model. This method incorporates the strengths in current diffraction rendering models, and combines the variable Fresnel coefficient of the specific material to augment diffraction effect; takes into account the absorption of photons, shadowing or masking of microfacets and interreflection in the interest of extending the applicable scopes of the height field microfacet; incorporates Wigner distribution function to defer the diffraction effects in order to further augment the microfacet model. Based on the geometrical optics theory, Monte Carlo sampling theory is used to solve the wave equation integral for the spatial distribution of the radiance on microfacets. Finally, a bidirectional reflectance distribution function diffraction optics model based on the light's wave equation is constructed, which can be applied to the ray-tracer. The experimental results demonstrate that our method can efficiently model the phase and amplitude of the wave to generate high-quality realistic diffraction effects, reducing the computational complexity of the wave equation

research on modeling and simulation of satellites surface optical reflection characteristics

在研究空间相机成像效果探测问题时,针对提高探测相机成像真实效果的需要,研究了卫星表面光学反射特性的建模与仿真方法。利用双向反射分布函数(BRDF)仿真卫星表面的光学反射特性,将卫星表面物理特性与其光学反射特性有机地结合起来。在VC.Net环境下开发卫星表面光学反射特性仿真软件,并将软件集成到空间探测相机成像效果仿真平台上。利用平台进行成像仿真实验,生成真实感仿真图片。仿真结果表明,BRDF能够精确仿真卫星表面的光学反射特性,使成像效果仿真更加准确和逼真

rendering realistic glare in real-time

针对现有眩光效果绘制方法的真实感和速度问题,提出一种基于GPU的真实感眩光效果绘制方法.首先根据光圈和镜头生成带有随机镜头噪声的二维衍射光栅图像;其次考虑夫琅禾费和菲涅耳2种不同的衍射效果,利用预存算法系数的快速傅里叶变换模拟衍射效果的光学过程,并通过衍射效果的光谱模型实现真实感绘制,同时利用2个独立的一维高斯卷积核加速实现bloom效果;再通过随机小角度旋转和混合操作进行真实感增强;最后采用实时光线跟踪渲染框架,在三维场景中实现了真实感眩光效果的实时绘制.该方法的主要步骤采用CUDA实现,充分利用了GPU强大的并行计算能力并兼顾考虑存储器优化策略.实验结果表明,文中方法绘制结果具有较强的真实感和实时性.国家“八六三”高技术研究发展计划(2009AA01Z303

基于Navarro示意眼模型的视觉真实感绘制

结合人眼光学建模和计算机图形学的真实感绘制技术,提出一种基于Navarro示意眼模型的人眼视觉真实感绘制方法。利用Navarro模型与传统的单透镜模型相比能够更精确地模拟人眼的特性,将Navarro模型引入视觉真实感绘制中;采用光线追踪方法,加入非球面折射面的计算,精确地模拟人眼的成像特性。实验结果表明此种方法能够更精确地模拟人眼的视网膜成像,通过更改模型参数也能够灵活地模拟人眼在不同视觉缺陷下的成像

schematic eye model-based vision-realistic rendering

结合人眼光学建模和计算机图形学的真实感绘制技术,提出一种基于 Navarro 示意眼模型的人眼视觉真实感绘制方法。利用 Navarro 模型与传统的单透镜模型相比能够更精确地模拟人眼的特性,将 Navarro 模型引入视觉真实感绘制中; 采用光线追踪方法,加入非球面折射面的计算,精确地模拟人眼的成像特性。实验结果表明此种方法能够更精确地模拟人眼的视网膜成像,通过更改模型参数也能够 灵活地模拟人眼在不同视觉缺陷下的成像。国家863计划资助项目Combining human eye modeling technology and realistic rendering of computer graphics,this paper proposed a vision-realistic rendering method based on Navarro schematic eye model． Compared with the previous single lens model,Navarros model could simulate more vision characteristics of human eye． Based on Navarros model,utilizing the distributed ray tracing,and compute aspheric surface ray path,simulated more accurate retinal image． Further more,by adjusting the shape parameter of cornea and lens,to change the total diopter of the eye,rendered retina images with exact myopia and hyperopia of different levels． The experiment results indicate that this method can generate more realistic retina images reflected vision characteristics of the human eye,and by adjusting the parameter of the model,it can easily simulate the eye defect

multi-core based algorithm for generating celestial background confusion effect

针对空间探测系统仿真中生成星空背景图像不能及时响应的弊端,提出一种利用多核加速生成星空背景图像的算法。阐述星空背景图像产生弥散效果的原理,在二维高斯模型的中心衰减函数基础之上对星空背景弥散效果进行建模仿真,并给出了一种基于多核处理器的并行实现方法。通过对不同恒星数目的星空背景进行仿真,分析了基于多核的并行算法相对于基于单核的串行算法的加速比,得出基于多核处理器的星空背景弥散效果实现算法基本能满足实时性要求。国家973重点基础研究发展计划基金项目(2009CB723906)Due to the defect that requirement of speed for digital image generation of celestial background cant be met in time, a algorithm of celestial background is proposed, which is accelerated by multi-cores processor. First of all, clarify principle of confusion in generating digital image of celestial background is expounded, confusion effect of celestial background based on center-attenuated function of two-dimension Gauss model is modeled and simulated. Then, confusion effect generation algorithm is proposed based on multi-core processors generating and integrating sub-picture on multi-core processor. On the condition of different counts of stars, accelerated-ratio with parallel algorithm based on multi-core processors compared is analyzed by serial algorithm based on single core. Ultimately, confusion effect generation algorithm based on multi-core processors is applied to meet requirement of generating images in time in spatial detecting system of stimulation

parallel acceleration for a gpu-based star catalogue retrieval algorithm

提出一种基于GPU的恒星检索并行算法,解决大视场下星表检索在仿真应用中效率不高的问题。首先使用经纬度分区法将星表划分为星区存储,然后在可快速查询的分区星表上,提出构造球面三角形法精确求出探测视场覆盖的星区,以有效减小搜索范围。最后,采用计算统一设备架构(CUDA)计算平台,将并行的视场内恒星检索过程放入GPU下进行并行加速。实验结果表明,与面向CPU的实现相比,所提算法获得数十倍的加速比,并且在大视场、宽星等域下将检索时间控制在毫秒级别,满足了实时仿真要求。A GPU-based parallel star retrieval method is proposed to improve the efficiency of searching stars from star catalogue in computer simulation, especially when the Field of View (FOV) is large. By the novel algorithm, the stars in catalogue are classified and stored in different zones by using latitude and longitude zoned method firstly. Based on the easily accessible star catalogue, the star zones covered by the FOV can be computed exactly by constructing a spherical triangle around the FOV. As a result, the searching scope is reduced effectively. Finally, a CUDA computation platform is used to run the parallel process of star retrieving from those star zones on GPU. Experimental results show that, in comparison with CPU-oriented implementation, the proposed algorithm achieves up to decades times speedup, and the processing time is limited within a millisecond level in large FOV and wide star magnitude domain. It meets the requirement of real-time simulation