Abstract: Client-server graphics transmission system wherein component capabilities are provided at the server and client locations for the following: to gather three dimensional graphics transmission performance parameters, including client rendering capabilities, server load, network bandwidth and optionally-provided user preferences; to evaluate the potential performance of different transmission methods which could be used to communicate a graphics data set from the server to the client; to choose and request a transmission method based upon the evaluating; to format the requested data set for transmission; and to provide the formatted data set for rendering at the display hardware associated with the client.

Abstract: A computer network system includes a plurality of computers each including a central processing unit (CPU), a memory and at least one peripheral device, a connection fabric having selectable first and second sides, the first side being coupled to a first computer of the plurality of computers and the second side being coupled to at least a second computer of the plurality of computers. Each of the first and second computers performs a negotiation to determine which one of the first and second computers controls resources of the other of the first and second computers.

Abstract: A procedure is embodied as program code on a medium that is readable by a computer. The program code is used to direct operation of the computer to render lines corresponding to samples, from a digitizer tablet, that map onto a same pixel of a display screen. The program code includes a code segment for subdividing a display screen pixel into a plurality of sub-pixels; a code segment, responsive to each sample that maps onto a current pixel, for mapping the sample onto a sub-pixel center; a code segment for computing a bounding box that is centered on the sample; a code segment, responsive to a size and position of the bounding box, for determining those pixels in a neighborhood of the current pixel that are overlapped by the bounding box; and a code segment for varying an intensity of the overlapped pixels according to the amount of overlap.

Abstract: A method (and system) of eliminating visible artifacts in overlapped projections produced by a plurality of projectors, includes in areas outside of the overlap areas, raising an intensity of predetermined color pixels to match a level of the predetermined color in the overlap areas, and simultaneously with the raising of the intensity, scaling values of pixels in the overlap areas such that the values do not exceed the maximum pixel value of a single projector of the plurality of projectors.

Abstract: Disclosed is a method and an apparatus, as well as a computer program, for associating digitizer tablet stroke samples with entries in an electronic personal information management (PIM) tool, such as an electronic organizer or an electronic calendar. A stroke database has a plurality of time stamped stroke entries, and a PIM database has a plurality of entries each having a time associated therewith. A controller searches at least one of the stroke database and the PIM database to locate corresponding entries in each database that indicate that a particular one of the stroke entries was created at a time that corresponds to a particular one of the PIM database entries. The controller is responsive to the search being successful for forming a link between the stroke entry and the PIM database entry for enabling corresponding stroke information to be visualized in association with the particular one of the PIM database entries.

Abstract: Client-server graphics transmission system wherein component capabilities are provided at the server and client locations for the following: to gather three dimensional graphics transmission performance parameters, including client rendering capabilities, server load, network bandwidth and optionally-provided user preferences; to evaluate the potential performance of different transmission methods which could be used to communicate a graphics data set from the server to the client; to choose and request a transmission method based upon the evaluating; to format the requested data set for transmission; and to provide the formatted data set for rendering at the display hardware associated with the client.

Abstract: A method and apparatus for combining two dimensional (2D) images with three dimensional (3D) polygonal models of objects so as to encode 2D image content information into the 3D objects, thereby providing an efficient rendering and transmission of complex scenes. The occurrence of an occlusion error in a digital data processing system that has a display is avoided. The method has steps of (a) encoding a specification of a two dimensional background image into at least one three dimensional foreground object that overlies and occludes a portion of the background image; and (b) displaying to a viewer the background image and the at least one overlying foreground object. A further step operates in response to a movement of the foreground object that makes a portion of the background image visible to the viewer, for (c) displaying the portion of the background image that has become visible. The step of displaying uses the encoded specification that is retrieved from the foreground object.

Abstract: In a panoramic scene represented by a first environment map comprising a plurality of elements each associated with a color value representing color of the corresponding element, hotlink areas in the scene are defined by a second environment map comprising a plurality of elements. The elements of the second environment map correspond to the elements of said first environment map according to a mapping function. At least one element of the second environment map is associated with hotlink data identifying an action to be performed upon user selection of at least one element of the first environment map that correspond to the at least one element of the second environment map.

Abstract: A method and apparatus for operating a client/server graphics processing system of a type that includes a display and a user input device. A first step, executed at the server entity, renders a plurality views (e.g., six views) of a model of interest and transmits the plurality of views to the client entity. A next step, executed at the client, maps individual ones of the plurality of views onto individual ones of a plurality of faces of a structure (e.g., a cube) and displays the structure on the display. In response to the user manipulating the user input device, a next step, executed at the client, causes a manipulation of the structure displayed on the display for specifying a particular view direction relative to the model.

Abstract: A Z-cache is provided for use in rasterizing computer generated images. The Z-cache allows for caching depth information such that a depth buffer may be implemented in system memory without degradation in performance of a depth routine for determining the visible information in a display. The Z-cache may store and compare pixel depth information. Thus, methods of using a z-cache in a graphics system as well as a graphics system, a processing system and a rasterizer are provided which utilize a Z-cache.

Abstract: A method and apparatus for a computer graphics rendering system which slices the traditional geometry pipeline into two phases to improve overall graphics system utilization is described. The graphics system consists of a host processor and a graphics adapter. The host creates work items and feeds them to the graphics adapter. In the two phase method, the first phase computes the clipping status and immediately returns this status information, before completion of the actual clipping, to the application running on the host processor to minimize stalling the host processor and hence the application. The second phase performs the rest of the work necessary to draw the objects on the screen. The advantage of two phase method is that the host processor minimizes its wait (but only for model/view transformation and clipping status determination) for a return status from the graphics adapter for the current work item and gets to create the next work item from the application sooner.

Abstract: In a multiprocessor system, such as a graphics data processing system, a method is disclosed for processing input data in a data processor pipeline. The method includes steps of operating a main thread to store input data in an input buffer until the input buffer is full or the input data ends. If a child thread does not exist, the method creates a child thread and assigns the input buffer to the child thread for processing. If a child thread already exists, the method determines if the child thread can be assigned the input buffer and, if so, then assigns the input buffer to the child thread for processing. If the child thread cannot be assigned the input buffer for processing, the main thread assigns the input buffer to itself for processing in parallel with processing being performed by the child thread. The steps of assigning and determining employ local variables that are accessible to both the main thread and the child thread, and that do not require an operating system call to change and/or test.

Abstract: Objects of a scene are grouped into sets. When rendering a plurality of pixels for display, for each pixel, a set identifier that corresponds to the visible object at the pixel is stored in an auxiliary buffer The information stored in the auxiliary buffer is utilized during picking in order to avoid the intensive task of traversing all of the objects of the scene to determine those objects intersected by the picking aperture.

Abstract: A method of optimizing the operation of a computer system in running application programs in accordance with system capabilities, user preferences and configuration parameters of the application program. More specifically, with this invention, an optimizing program gathers information on the system capabilities, user preferences and configuration parameters of the application program to maximize the operation of the application program or computer system. Further, user selected rules of operation can be selected by dragging rule icons to target optimizer icon.

Abstract: An image to be clipped is decomposed into its edges and the edges simultaneously clipped by multiple execution units of a SIMD computer along pairs of parallel clip planes. Successive parallel operations are performed on polygons recomposed using the clipped output edges, until all clipping has been performed.

Abstract: While executing the standard graphics processing steps, problem polygons (i.e., those outside of a defined clip volume) are buffered for later processing, while the standard graphics processing continues, without the need for periodically reformatting data and performing clipping. After either a predefined number of polygons have been stored at the buffer location, or at such time as a change in the rendering state occurs, the buffered polygons are clipped.

Abstract: In a multiprocessor system, such as a graphics data processing system, a method is disclosed for synchronizing the operations of two threads so as to execute a graphics data computation task with only one of the two threads. The method includes the steps of providing a set of local variables that are accessible, only through an atomic operation, by both of the threads. Before accessing a graphics data work buffer with one of the threads, testing a plurality of the local variables to ensure that the other thread has not already accessed the work buffer and, if it has not, setting one of the local variables to deny the other thread access to the work buffer. The method further includes the steps of accessing the work buffer and executing the graphics data computation task using the contents of the work buffer.

Abstract: The computer system of the present invention generates a view of a scene by storing in memory color values associated with elements of an environment map representing the scene and color values associated with elements of a bit map image that is separate from the environment map. The bit map image is orientated with respect to the coordinate system of the environment map. The environment map is projected onto a view window that comprises an array of pixels. For at least one pixel of the view window covered by the bit map image, the element of the bit map image that corresponds to the pixel of the view plane is determined and a color value of the pixel is derived based upon the color value of the corresponding element of the bit map image. The derived color value of the pixel of the view window is stored for display. The computer system may also store in memory depth values associated with the elements of the bit map image and depth values associated with pixels of the view window.

Abstract: A method is disclosed for operating a software-managed cache memory (30), and includes steps of: (a) registering with an operating system (12A), for at least one thread of a plurality of threads, a memory allocation function; in response to the execution of a first thread being halted, (b) determining if a next thread to be executed has registered a request to be allocated all or a portion of the memory; and (c) swapping-out the memory allocated to the first thread if the first thread has previously registered a memory callback function and if the next thread has made a request to be allocated an amount of memory that exceeds an amount that is not already allocated.

Abstract: The method and apparatus of the present invention groups the objects of the scene into sets. When rendering a plurality of pixels for display, for each pixel, a set identifier that corresponds to the visible object at the pixel is stored in an auxiliary buffer. The information stored in the auxiliary buffer is utilized during picking. The picking operation of the present invention is an improvement over the conventional picking techniques because the present invention avoids the intensive task of traversing all of the objects of the scene to determine those objects intersected by the picking aperture.