Abstract: Apparatus is provided to enable real-time volume rendering on a personal computer or a desktop computer in which a technique involving blocking of voxel data organizes the data so that all voxels within a block are stored at consecutive memory addresses within a single memory model, making possible fetching an entire block of data in a burst rather than one voxel at a time. This permits utilization of DRAM memory modules which provide high capacity and low cost with substantial space savings. Additional techniques including sectioning reduces the amount of intermediate storage in a processing pipeline to an acceptable level for semiconductor implementation. A multiplexing technique takes advantage of blocking to reduce the amount of data needed to be transmitted per block, thus reducing the number of pins and the rates at which data must be transmitted across the pins connecting adjacent processing modules with each other.

Abstract: A system for quickly finding a point in a virtual environment "on the gro" or beneath another point involves finding the intersection of a "ground" polygon representing the terrain with a single ray representing the direction of gravity emanating from the original point. After appropriate polygons are selected, they are intersected with the gravity vector to determine which ones are just under the point in question, with the closest point being returned as the ground point. Polygons are sorted into a variable depth quadtree structure, where the leaves contain a predetermined maximum number of polygons, with each quadtree node being subdivided based on a polygon vertex located inside the current quadtree node. A planar space subdivision of each quadtree node is created using the edges of the polygons that overlap that node. The system for rapid ground point determination intersects lines of a predetermined orientation, e.g.

Abstract: In an ATM network, a traffic management system is provided to allow simple nd effective implementation of rate-based available bit rate, or ABR, flow control at ATM switches, with the subject system using an innovative queue length based approach to calculate the cell rate that a source system can use to send cells. In one embodiment, the cell rate is calculated as an exponential function of the cell queue length at a switch, and the rate value is carried back to a source system via resource management, or RM, cells. The exponential rate calculation function provides a large stability region for a network for better flow control performance than other systems, with the subject system being easy to implement in ATM switches.

Abstract: A computer network guarantees timeliness to distributed real-time applicans by allowing an application to specify its timeliness requirements and by ensuring that a data source can meet the specified requirements. A reflective memory area is established by either a data source or an application. A data source maps onto this reflective memory area and writes data into it. In order to receive data from this data source, an application requests attachment to the reflective memory area to which the data source is mapped and specifies timeliness requirements. The application may specify that it needs data either periodically or upon occurrence of some condition. The application allocates buffers at its local node to receive data. The data source then establishes a data push agent thread at its local node, and a virtual channel over the computer network between the data push agent thread and the application attached to its reflective memory area.

Abstract: A system for generating a set of graphical images based upon application of different graphical transfer functions to data of physical structures in a scene. The application of the different graphical transfer functions define graphical images of a single scene having different characteristics. A user can then review the images to select a desirable image, without having to define or know the graphical transfer function which generates the image. The system of the present invention generates a dispersed set of output vectors representing characteristics of the set of images based upon a transfer function. The system creates the dispersed set by generating a random set of output vectors and then randomly perturbing one. The perturbed vector replaces one of the other vectors if the replacement results in a more dispersed set. The process is repeated until a thoroughly dispersed set of output vectors has been obtained.

Abstract: A universal modem has a software-configurable modulator/demodulator which commodates different modulation formats such as those associated with terrestrial, cable, phone line, satellite and wireless communications to be transmitted and received through a single device in which the modem has reconfigurable logic to accommodate the format of the signals being received or transmitted. Note that the modulator or demodulator can be used separately or the two units can be combined and used for transceivers, with either the same software configuring both the modulator and demodulator, or with different software used for the two units. In the receive mode, the universal modem detects the modulation format of the incoming signal and reconfigures the logic of its software-configurable demodulator to output demodulated digital data for further processing.

Abstract: A system generates and arranges animation sequences of articulated characs for review and selection by a user. Motion of articulated characters is based upon input parameters, such as torques at joints of the character. The system can be used to select appropriate parameters to obtain desirable motion of the articulated characters. The system generates a set of input vectors containing parameters of the motion. The input parameters are then processed to determine animation sequences and corresponding output vectors. The output vectors include characteristics of the motion. The input vectors are selected to provide a dispersed set of output vectors. A large number of random input vectors can be generated and then culled to leave a dispersed set of output vectors. Alternatively, a set of randomly generated input vectors of a predetermined size are randomly perturbed, to further disperse the output vectors.

Abstract: A computer-based system for automatic pagination and layout of yellow pages or a commercial telephone directory uses a simulated annealing heuristic to refine a randomly determined candidate solution. The text and advertisements which are to be included in the yellow pages directory are ordered in two distinct data streams representing the order of text and the order of advertisements in the directory. The system determines a possible layout, called a candidate solution, by randomly setting parameters defining the pagination and layout. These parameters may include page breaks in the advertisement stream, column numbers for each advertisement, and an amount of padding or empty space to be added to each page. Once the parameters are set, the individual pages are laid out by putting the advertisements in the next available position in their assigned columns, and the text around the advertisements. The solution is scored based upon the guidelines for the format and layout of the yellow pages directory.

Abstract: A network interface for a connection-based communication network has support for remote operations with reply, such as a remote read operation, that bypass host computer interaction. Such a network interface has support for general message processing operations which bypass host processor involvement. Message processing is low level processing of message between the host computer and the network. Such processing is performed on transmission in response to control information provided by the host and is performed on reception in response to control information included in incoming messages. Message processing includes low latency remote read and remote write operations, message filtering, and message demultiplexing. Such a network interface handles incoming messages containing destination control information indicating an operation to be performed, and possibly one or more operands.