公开(公告)号：US06750862B1

公开(公告)日：2004-06-15

申请号：US09067321

申请日：1998-04-27

申请人： Christopher W. Shaw ,  Goran Devic ,  Evan Leland

发明人： Christopher W. Shaw ,  Goran Devic ,  Evan Leland

IPC分类号： G06T1550

CPC分类号： G06T15/506 ,  G06T15/04

摘要： A method and system for performing enhanced lighting functions with respect to texture map data is operable within a computer controlled graphics display system and allows defined portions of a texture map to bypass prescribed lighting processes. Within a texture map, each texel data (u,v) is defined to contain color information and a control code (e.g., “texel light bit”). The texel light bit indicates to the lighting process whether or not texel color modulation is to occur to this texel data. In one embodiment, if the texel light bit is set, then no lighting modifications (e.g., color modulations) are performed with respect to the texel data. Also, if the texel light bit is not set, then normal lighting modifications are performed with respect to the texel data. In this way, the present invention allows texture map data to be lit in a non-uniform manner across a same graphics primitive. The present invention is particularly useful with respect to graphics objects (e.g., lights, indicator bulbs, glowing regions of the texture map) which should remain unaffected by external light sources (e.g., the sun, the moon, darkness of the night) within a three-dimensional graphic scene. By defining certain texel regions as having “texel lights”, the present invention then bypasses the external lighting conditions applied to the display scene for these regions.

摘要翻译： 用于执行关于纹理映射数据的增强照明功能的方法和系统可在计算机控制的图形显示系统内操作，并允许纹理贴图的限定部分绕过规定的照明处理。 在纹理图中，每个纹素数据（u，v）被定义为包含颜色信息和控制码（例如，“纹素光比特”）。 纹理光比特向照明处理指示纹理数据是否发生纹素色调。 在一个实施例中，如果纹理光比特被设置，则相对于纹理数据不执行照明修改（例如，颜色调制）。 此外，如果纹理光比特未设置，则相对于纹理数据执行正常的照明修改。 以这种方式，本发明允许纹理贴图数据以不均匀的方式跨越相同的图形原语点亮。 本发明对于应当保持不受外部光源（例如，太阳，月亮，夜间黑暗）的影响的图形对象（例如，灯，指示灯，发光区域的纹理图）是特别有用的 三维图形场景。 通过将某些纹素区域定义为具有“纹素光”，本发明然后绕过施加到这些区域的显示场景的外部照明条件。

公开(公告)号：US06567083B1

公开(公告)日：2003-05-20

申请号：US08937793

申请日：1997-09-25

申请人： Daniel R. Baum ,  Patrick M. Hanrahan ,  Matthew M. Pharr

发明人： Daniel R. Baum ,  Patrick M. Hanrahan ,  Matthew M. Pharr

IPC分类号： G06T1550

CPC分类号： G06T15/506

摘要： A method, system, and computer program product are provided that represent complex point and area illumination in computer graphics shading and animation. An irradiance vector field table representative of an irradiance field for a scene to be rendered is generated and stored in a texture memory. During rendering, the scene is lit based on irradiance vectors in the irradiance vector field table. For each point being lit, a corresponding irradiance vector is generated from the irradiance vector field table. A vector operation is performed between the irradiance vector and a surface normal for the point to compute an irradiance energy component. In one example hardware embodiment, a look-up unit looks up and interpolates irradiance vectors for selected points in the irradiance vector field table to compute an interpolated irradiance vector. A dot product unit calculates a dot product between the interpolated irradiance vector and a surface normal for the point being shaded and outputs an irradiance energy component for use in shading. The irradiance vector field table can represent an irradiance field for one or more complex point and area light sources. A set of multi-resolutional irradiance field tables covering progressively larger regions of a scene at progressively coarser resolutions is generated. One or more rendering passes are used to render a computer graphics image representing illumination from a complex point or area source. The irradiance vector field table can be generated to account for shadows and/or participating media such as fog or smoke. Shadow maps and back-projection or shadow volume algorithms can be used to determine light source visibility which is used to scale the irradiance energy component.

摘要翻译： 提供了一种方法，系统和计算机程序产品，其表示计算机图形着色和动画中的复杂点和面积照明。 生成表示要渲染的场景的辐照场的辐照矢量场表，并将其存储在纹理存储器中。 在渲染过程中，场景基于辐照度矢量场表中的辐照度矢量点亮。 对于每个被点亮的点，从辐照度矢量场表生成相应的辐照度矢量。 在辐照度矢量和点的表面法线之间执行向量运算，以计算辐照度能量分量。 在一个示例硬件实施例中，查找单元查找并内插辐照度矢量场表中的选定点的辐照度矢量以计算内插辐照度矢量。 点积单位计算内插辐照度矢量和被遮蔽点的表面法线之间的点积，并输出用于阴影的辐照能量分量。 辐照度矢量场表可以表示一个或多个复杂点和区域光源的辐照场。 产生了一组多分辨辐照场表，涵盖逐渐更粗糙的分辨率逐渐变大的场景区域。 一个或多个渲染遍用于渲染表示来自复杂点或区域源的照明的计算机图形图像。 可以生成辐照度矢量场表以考虑阴影和/或参与介质，例如雾或烟。 阴影图和背投影或阴影体积算法可用于确定用于缩放辐照度能量分量的光源可见度。

公开(公告)号：US06556200B1

公开(公告)日：2003-04-29

申请号：US09388338

申请日：1999-09-01

申请人： Hanspeter Pfister ,  Kevin A. Kreeger ,  Joseph W. Marks ,  Chia Shen

发明人： Hanspeter Pfister ,  Kevin A. Kreeger ,  Joseph W. Marks ,  Chia Shen

IPC分类号： G06T1550

CPC分类号： G06T15/55 ,  G06T15/06

摘要： A method traces rays through graphical data. The method partitions the graphical data into a plurality of blocks according to a scheduling grid. For each block, a ray queue is generated. Each entry in the ray queue representing a ray to be traced through the block. The ray queues are ordered spatially and temporally using a dependency graph. The rays are traced through the blocks according to the ordered list.

摘要翻译： 一种方法通过图形数据跟踪光线。 该方法根据调度网格将图形数据分割成多个块。 对于每个块，生成射线队列。 射线队列中的每个条目表示要通过块追踪的射线。 射线队列使用依赖图在空间和时间上排序。 根据有序列表，光线通过块进行跟踪。

公开(公告)号：US06529193B1

公开(公告)日：2003-03-04

申请号：US08880418

申请日：1997-06-23

申请人： Rolf Herken ,  Martin Grabenstein

发明人： Rolf Herken ,  Martin Grabenstein

IPC分类号： G06T1550

CPC分类号： G06T15/50 ,  G06T15/506 ,  G06T15/55

摘要： A computer graphics system and a method for generating pixel values in an image of objects using strictly-deterministic low-discrepancy sequences as sample points for evaluating integrals which are used to simulate a number of computer graphic techniques including soft shadows, simulation of depth of field, motion blur, jittering, and global illumination. Unlike the random numbers used in connection with the Monte Carlo technique, the low discrepancy sequences ensure that the sample points are evenly distributed over a respective region or time interval, thereby reducing clumping of such sample points. The invention facilitates the generation of images of improved quality when using the same number of sample points at the same computational cost as in the Monte Carlo technique.

摘要翻译： 计算机图形系统和用于使用严格确定性的低差异序列作为用于评估积分的样本点来生成对象图像中的像素值的方法，所述积分用于模拟包括软阴影在内的许多计算机图形技术，景深模拟 ，运动模糊，抖动和全局照明。 与与蒙特卡罗技术相关的随机数不同，低差异序列确保采样点在相应的区域或时间间隔内均匀分布，从而减少这些采样点的聚集。 当以与蒙特卡罗技术相同的计算成本使用相同数量的采样点时，本发明有助于产生改进质量的图像。

公开(公告)号：US06437781B1

公开(公告)日：2002-08-20

申请号：US08866556

申请日：1997-05-30

申请人： S. Paul Tucker ,  Bradly J. Foster ,  Steven J. Kommrusch

发明人： S. Paul Tucker ,  Bradly J. Foster ,  Steven J. Kommrusch

IPC分类号： G06T1550

CPC分类号： G06T15/503

摘要： A computer graphics system includes an apparatus for fog blending colors to be displayed on a graphics display of the computer graphics system. The computer graphics system includes a rendering parameter calculation unit responsive to data of a primitive, that determines a cooked exponent value and a color value for at least one pixel of the primitive. In addition, the system includes a fog unit responsive to the cooked exponent value for each pixel of the primitive, that determines a fog blending factor for each pixel of the primitive, wherein the fog blending factor is one of an exponential fog blending factor and an exponential-squared fog blending factor. Further, the system includes a fog blending unit responsive to the color value and the fog blending factor for each pixel of the primitive and also to a fog color value, that blends the fog color value with the color value for each pixel of the primitive according to the fog blending factor for the respective pixel, and that provides a fogged color value for each pixel of the primitive. In addition, the computer graphics system may include a first interpolator, responsive to the color value and the cooked exponent value for at least one pixel of the primitive, that determines the color value and the cooked exponent value along an edge of the primitive so as to provide the cooked exponent value and the color value for each pixel of the edge of the primitive. Further, the computer graphics system may also include a second interpolator, responsive to the cooked exponent value and the color value for each pixel of the edge of the primitive, that determines the cooked exponent value and the color value along a span of the primitive so as to provide the cooked exponent value and the color value for each pixel of the span of the primitive. In this way, the system provides fast and accurate exponential and exponential-squared fog blending of the color values of the primitive without a lot of hardware.

公开(公告)号：US06366283B1

公开(公告)日：2002-04-02

申请号：US09261145

申请日：1999-03-03

申请人： Filippo Tampieri

发明人： Filippo Tampieri

IPC分类号： G06T1550

CPC分类号： G06T15/55

摘要： Image data is generated for a scene, in which the scene includes object surfaces in three-dimensions. Intersecting or touching surfaces are identified by analyzing the surfaces within a hierarchy of bounding volumes. Thereafter, a multi-resolution representation of a radiosity equation is constructed for the scene, wherein one of the identified surfaces is considered separately for light emission on either side of a previously identified line of contact or intersection.

摘要翻译： 为场景生成图像数据，其中场景包含三维对象表面。 通过分析界限卷层次结构中的曲面来识别相交或触摸曲面。 此后，对于场景构造辐射度方程的多分辨率表示，其中所识别的表面中的一个被单独考虑用于先前识别的接触线或交叉点的任一侧上的发光。

公开(公告)号：US06232979B1

公开(公告)日：2001-05-15

申请号：US08995138

申请日：1997-12-19

申请人： Ofer Shochet

发明人： Ofer Shochet

IPC分类号： G06T1550

CPC分类号： G06T15/04

摘要： A method, system, and computer program product are provided for fast computation using parallel resampling and blending in multi-channel texture mapping. In one embodiment, slices of projection data for volume rendering are loaded into multiple textures. The loaded textures are combined using multi-channel texture mapping to obtain a multi-channel data frame for storage in a multi-channel frame buffer. The multiple textures are combined using a texture mapping operation that includes a linear blending operation, such as, a maximum, minimum, and/or sum blending operation. Multi-channel frame buffer data is then aggregated to obtain a final single channel grey-level output of pixel data. In one example implementation of the present invention, a load unit loads slices of projection data into multiple textures. A multi-channel texture engine combines the multiple textures to obtain multi-channel frame data for storage in a multi-channel frame buffer. The texture engine performs a texture mapping operation using a linear blending operation, such as, a maximum, minimum, and/or sum blending operation. An aggregation unit, such as a summer unit, aggregates the multi-channel frame buffer data to obtain a final single channel grey-level output of pixel data. The present invention leverages the parallel resampling and blending operations available in multi-channel texture engines so that fewer resampling operations are required in computational tasks, such as, volume rendering of projection data.

摘要翻译： 提供了一种方法，系统和计算机程序产品，用于在多通道纹理映射中使用并行重采样和混合进行快速计算。 在一个实施例中，用于体绘制的投影数据的片段被加载到多个纹理中。 使用多通道纹理映射来组合加载的纹理以获得用于存储在多通道帧缓冲​​器中的多通道数据帧。 使用纹理映射操作来组合多个纹理，该纹理映射操作包括线性混合操作，例如最大值，最小值和/或求和混合操作。 然后聚合多通道帧缓冲​​器数据以获得像素数据的最终单通道灰度级输出。 在本发明的一个示例实现中，负载单元将投影数据的片段加载到多个纹理中。 多通道纹理引擎组合多个纹理以获得多通道帧数据以存储在多通道帧缓冲​​器中。 纹理引擎使用线性混合操作，例如最大值，最小值和/或求和混合操作来执行纹理映射操作。 诸如加法单元的聚合单元聚合多通道帧缓冲​​器数据以获得像素数据的最终单通道灰度级输出。 本发明利用在多通道纹理引擎中可用的并行重采样和混合操作，使得在诸如投影数据的体绘制等计算任务中需要更少的重采样操作。

公开(公告)号：US06806875B2

公开(公告)日：2004-10-19

申请号：US10175805

申请日：2002-06-21

申请人： Yasuhiro Nakatsuka ,  Shigeru Matsuo ,  Jun Satoh ,  Masanori Miyoshi ,  Koyo Katsura ,  Takashi Sone

发明人： Yasuhiro Nakatsuka ,  Shigeru Matsuo ,  Jun Satoh ,  Masanori Miyoshi ,  Koyo Katsura ,  Takashi Sone

IPC分类号： G06T1550

CPC分类号： G06T1/60 ,  G06T11/40 ,  G06T15/50 ,  G06T15/80

摘要： In a data processor and a shading apparatus used in the data processor, the data processor selects an address based on the information of a memory or a translation look-aside buffer. Therefore, even when the same data are accessed, a different address at high speed is adopted according to the hardware, object to be processed, processing, etc. A plurality of geometric vectors are given as the parameters for the vertexes of a picture, the vectors are interpolated in the picture, and the luminance of each small area in the figure is calculated using the vectors generated by the interpolation. Therefore, a spotlight or highlight can be expressed with high accuracy and at high speed even when the amount of the hardware and the extent of the picture are small.

摘要翻译： 在数据处理器中使用的数据处理器和着色装置中，数据处理器根据存储器或翻译后备缓冲器的信息来选择一个地址。 因此，即使在访问相同的数据的情况下，也可以根据硬件，被处理对象，处理等来采用高速的不同的地址。作为图像的顶点的参数，给出多个几何矢量， 矢量被内插在图像中，并且使用通过内插生成的矢量来计算图中每个小区域的亮度。 因此，即使当硬件的数量和图像的程度小时，也可以高精度和高速度地表现聚光灯或高光。

公开(公告)号：US06765573B2

公开(公告)日：2004-07-20

申请号：US09899802

申请日：2001-07-06

申请人： Cyriaque Kouadio

发明人： Cyriaque Kouadio

IPC分类号： G06T1550

CPC分类号： G06T15/80 ,  G06T15/04 ,  G06T15/50

摘要： An improved surface shading method computes and stores light reflectance values as a texture map for a given light direction and view direction to an object in a scene during development of a computer graphics (CG) program, and uses the stored texture map later for shading during real-time rendering. A selected bidirectional reflectance distribution function (BRDF) is applied using a standard model for distribution of normal direction vectors for a given type of surface, and BRDF values are computed as a global texture map for the object's surface in the scene. The BRDF values are stored as a look-up table indexed to the sampled range of normal direction vectors. During real-time rendering, surface shading can be readily processed by using the normal direction vector for any given point to look up the stored BRDF value. Shading with BRDF light reflectance values can be combined in one or more passes with shading of other surface texture characteristics, e.g., a facial skin surface textured with hair and facial features. In this manner, the rich tones of a physical light reflectance model can be obtained even for highly textured surfaces during real-time rendering. Besides standard types of light reflectance models (Torrance-Sparrow, Phong, Strauss, etc.), modified types of BRDF models (e.g., Schlick) may also be used to derive a BRDF texture map.

摘要翻译： 改进的表面阴影方法在计算机图形（CG）程序的开发期间计算并存储光反射率值作为给定光方向的纹理图和在场景中的对象的视图方向，并且在以下期间将所存储的纹理贴图用于阴影 实时渲染。 使用用于给定类型表面的法向方向向量分布的标准模型来应用所选择的双向反射分布函数（BRDF），并且将BRDF值计算为场景中物体表面的全局纹理图。 BRDF值被存储为索引到法线方向向量的采样范围的查找表。 在实时渲染过程中，通过使用任意给定点的法线方向向量可以容易地处理表面阴影，以查找存储的BRDF值。 用BRDF光反射值遮蔽可以在一次或多次通过中与其他表面纹理特征（例如，用毛发和面部特征纹理化的面部皮肤表面）的阴影相结合。 以这种方式，即使在实时渲染期间对于高度纹理化的表面，也可以获得物理光反射率模型的丰富色调。 除了标准类型的光反射率模型（Torrance-Sparrow，Phong，Strauss等）之外，还可以使用修改的BRDF模型（例如，Schlick）来获得BRDF纹理图。

公开(公告)号：US06639594B2

公开(公告)日：2003-10-28

申请号：US09681773

申请日：2001-06-03

申请人： Zhengyou Zhang ,  Ko Nishino ,  Katsushi Ikeuchi

发明人： Zhengyou Zhang ,  Ko Nishino ,  Katsushi Ikeuchi

IPC分类号： G06T1550

CPC分类号： G06T15/506

摘要： A system and process for efficiently representing an object and allowing the synthesizing of photo-realistic images of the object that depict both diffuse and specular reflections therefrom. This is accomplished using a sparse set of input images and a geometric model of the object. In particular, the reflectance components (i.e., diffuse and specular) are separated out of the input images based on the intensity variation of object surface points. The diffuse reflection component is characterized with a global texture map, while the specular reflection components are used to model the illumination distribution of the environment surrounding the object and to estimate the surface reflectance parameters. This framework provides a very compact representation of the object's appearance. Photo-realistic virtual images of the object from any desired viewpoint can be synthesized using the previously computed global texture map, illumination distribution, and reflectance parameters.