Abstract: A system and method for deforming objects uses delta free-form deformations (DFFD). The DFFD computes a delta vector based on a conventional free-form deformation (FFD) and an original vertex. Multiple delta vectors can be computed and combined for each vertex. Because delta vectors are independent from each other, various operations such as rotations and translations in addition to multiple overlapping deformations are applied to the vertex with superior results over the conventional FFD.

Abstract: In order to reduce the amount of computation processing and simplify processing, a graphic processor apparatus includes a graphic signal generator circuit for generating video images such as graphics and characters, and a filter processor circuit for conducting filter processing on video images outputted from said graphic signal generator circuit. Anti-alias processing for reducing jaggy phenomena and flicker removing processing are simultaneously conducted in the filter processor circuit.

Abstract: A computer graphics display system and method are described for rendering objects formed of at least one geometric primitive as pixel images which collide or intersect in three dimensional space. A depth buffer stores depth information representing graphics images rendered by the graphics system. Data stored in the depth buffer representing graphics objects displayed in the three dimensional space are partitioned into three portions comprising an identification portion to store information identifying each object rendered in the three dimensional space, an object resolution portion to store data for controlling the resolution of the graphics object on a display screen, and a depth coordinate portion for storing the coordination information of the object rendered in the three dimensional space. A collision detection is provided to detect and determine when two objects collide on the display screen.

Abstract: In a computer operated three-dimensional shape modeler where a group of parts are to be edified, a view of the parts layout is selected by the designer and list of the parts is created in the computer memory for that view. A part in the list is designated as a target part. A designer sketches a two-dimensional figure, which relates to a design change, on surfaces of the group of parts in the layout view. A cross section of the designated target part is automatically set as a "sketch surface". The cross sectional shape of the selected surface of the target part is modified by the two-dimensional sketch figure. A second part is designated as the target part and that part is switched over the other parts in the list. A cross section of the second target part is also automatically set as a sketch surface. The cross sectional shape of the surface of the second target part is modified in a similar fashion as the modification to the first part.

Abstract: A method for depth complexity reduction includes inserting checkpoints between depth sorted object sections in a stream of geometric primitives. In response to receiving a checkpoint while rasterizing primitives for an image region, coverage data stored for the image region is checked to determine whether each pixel in the image region is fully covered. If so, then additional primitives for the image region can be ignored to avoid rendering occluded geometry.

Abstract: A three-dimensional graphic display apparatus performs hidden surface removal and color blending. Particularly, the graphic display apparatus includes a configuration of a special purpose memory for graphics, thereby forming a configuration of a graphic display apparatus using the special purpose memory. The special purpose memory for graphics includes a memory cell holding intensity information (RGB) and window information about each pixel, an XY coordinate converter converting XY coordinates of a pixel to be written to a memory address, an intensity blending processor, and hidden-surface removal and window comparators, all of which are formed on the same chip.

Abstract: A system and method for weighting one or more vertices in a region being deformed by free-form deformation techniques assigns a weight a vertex based on the position of that vertex within the deformation lattice. The assigned weight is used to alter the amount of displacement that the free-form deformation would otherwise have on the vertex by an amount proportional to the weight.

Abstract: Automatic photographic color rendering of the surfaces of wire frame representation of 3-dimensional objects is described. Bit mapped information of surface areas is captured as part of image processing in the creation of wire frames into the computer. When a wire frame is transformed to a different orientation, the rendering surfaces are automatically transformed and the wire frame can be rendered in the new orientation with photographic quality.

Abstract: A computer-implemented shading system includes a geometric renderer which renders a computer generated image to produce geometric image information for an object in a scene, and a user interface which permits a user to selectively vary a designated parameter(s) to affect how that object is shaded. The system also includes a specialized shader to shade the object in the scene according to the designated parameter(s) and other shading parameters. The specialized shader is created from the user's original shader. The specialized shader has a cache loader which contains all of the terms of the user's original shader, plus load operations to load values from computations that do not depend from the designated parameter(s). The specialized shader also has a cache reader which contains a reduced set of terms from the original shader that depend on the designated parameter(s), plus read operations to read the values of the non-variant terms from the cache.

Abstract: An image processing apparatus for forming a high-quality surface display image at high speed is provided. From raw data input by a medical image diagnosis apparatus, gray-level volume data and binary volume data in which a region-of-interest is extracted by binarizing are obtained. The binary volume data is subjected to ray-casting and projected onto a screen. A depth image formed of pixels on the screen and a distance between the screen and the surface (surface voxel) of a display object is obtained. The coordinates of the surface voxels are calculated from the depth image. Surface normals are obtained from voxel values of the gray-level volume data and a voxel values in the vicinity, and a shaded image is formed on the basis of surface normals.

Abstract: Moving output images are presented to a two dimensional display, such as a conventional television receiver (26). Three video sources are read from a compact disc, a notional front image and a notional back image being in the form of CD-I A and B planes. A notional back plane is a full frame, full video rate image, read from the disc as a coded MPEG data stream. After decoding, each pixel of each image includes depth data and opacity data. It is thus possible for an image in the notional front or notional middle plane to pass behind an object in the notional back plane. The depth and opacity data is severely compressed for the MPEG stream, by a process of quantisation and run-length encoding. The low resolution depth values for each pixel are converted to high resolution depth values via a look up table in order to further define the depth of each notional plane.

Abstract: A method for simulating and rendering hair. A simulator calculates the motion dynamics of a hair. The simulator includes a particle system that emits particles from a surface and a normalization module that normalizes the trajectory of each of the particles to a fixed length to form a set of normalized segments. The simulator outputs a list of normalized segments that are passed to a renderer. The renderer performs a variety of tasks, including fuzzy segment generation and self-shadowing, that results in an image being displayed on a display device. That is, the renderer takes three-dimensional spacial information, applies a light to this information and renders this information as a two-dimensional image.

Abstract: Before being used in an interactive graphics environment, control points defining Bezier curves are processed to determine the curvature of the patch. This value is then used to determine the number of recursive iterations required to divide the patch into a plurality of renderable polygons. A value is determined by considering the cosine of the turning angle between vectors connecting the control points of Bezier curves. For each vector connecting the control points a respective vector of unit length is calculated. Cosine values are then calculated by producing the dot product of said unit vectors. Cosine values for two turning angles are calculated for each Bezier curve and a value indicative of curvature is determined by adding these cosine values together. The curvature of the whole patch is taken to be equivalent to the curvature of the most curved curve defining the patch.

Abstract: A pixel engine pipeline (including a "front-end" and a "back-end") communicates pixel information between a graphics processor, a pixel engine, a data cache, and system memory. The "front-end" (for reading requested data) includes a command queue for receiving graphics instructions from a graphics processor. Read requests in the command queue are stored in a read request queue. Extraction instructions corresponding to at least a portion of the read request are stored in an attribute queue. Control logic determines whether the requested data is located in a data cache. The read request is stored in a load request queue and the requested data is retrieved from system memory into a load data queue, if the requested data is not in the data cache. The control logic stores the requested data into a read data queue. The requested data is provided to a stage of the pixel engine from the read data queue in accordance with the extraction instructions.

Abstract: A method for simulating and rendering hair. A simulator calculates the motion dynamics of a hair. The simulator includes a particle system that emits particles from a surface and a normalization module that normalizes the trajectory of each of the particles to a fixed length to form a set of normalized segments. The simulator outputs a list of normalized segments that are passed to a renderer. The renderer performs a variety of tasks, including fuzzy segment generation and self-shadowing, that results in an image being displayed on a display device. That is, the renderer takes three-dimensional spacial information, applies a light to this information and renders this information as a two-dimensional image.

Abstract: In apparatus for processing image data representing multi-dimensional objects, data is stored defining the position of a light source, a viewing position, an arrangement of polygons defining an object and a local transform for transforming said object into viewable 3-dimensional space. Processing means defines the extent of points for an object in each dimension, performs said local transform on said points and determines the extent to which said points are transformed into viewing space. Thus, an evaluation can be made as to where the object will lie in viewing space before polygons are transformed. Culling may then be performed at the object level, rather than at the polygon level.

Abstract: In a signal processing method for use in a three-dimensional computer graphics system, in order to increase the processing speed between the raster engine and a frame buffer, the frame buffer is accessed by an interleaving method and a Z-value comparison is performed in a Z-buffer of the frame buffer. The bandwidth of the frame buffer can be improved by executing a modify cycle in a memory.

Abstract: A function processing system processes functions to make a three-dimensional display on a screen of a display means by connecting a plurality of lattice points of a space coordinate in a three-dimensional space region. The function processing system includes a computing system for computing a function value at each of the lattice points by a multivariable function having the space coordinate as an independent variable, where the computing system replaces the multivariable function by a product of a predetermined number of single variable functions and computing each of the single variable functions in advance so that the multivariable function is computed based on function values of each of the single variable functions, and a storage unit for storing the function values of the single variable functions which are computed in advance by the computing system. The computing system reads the stored function values of the single variable functions from the storage unit when computing the multivariable function.

Abstract: Methods and apparatus are disclosed for the rapid creation of wire frame representations of 3-dimensional objects using generic wire frames which are prototypical of a class of objects and which are modifiable to correspond to a specific instance of the class. A set of generic wire frames are bundled as a tool kit with software for editing wire frames. A method of morphing from a source 3-dimensional stereo rendered wire frame to a target rendered wire frame is also disclosed and the apparent camera viewpoint can change during morphing.

Abstract: To provide high-speed volume rendering without computing the points at which a viewing ray intersects with the boundaries of a volume data area.