Abstract: A method for displaying a stereo eye image on a curved surface is disclosed. A mathematical model of a computer generated scene having a vertex may be generated. A mono vertex vector may be calculated normal to the curved surface at the vertex location on the curved surface to a center of a viewer position. A left vertex may be calculated by applying a cross product to the vertex vector and a viewer's eye position vector. A right vertex may be calculated into the frame buffer by applying the cross product to the vertex vector and a negative viewer's eye position vector. The calculated points may be projected onto a curved surface for viewing.

Abstract: A method and an apparatus for improved pixel shading. The method of the present invention is based upon the notion of allowing multiple polygons to contribute to the net transmittance effect of a single pixel. This is accomplished by providing a new multi-sample data structure which can store visual attributes for each polygon, sorting all the transparent polygons in a front-to-back arrangement, processing the transparent polygon records and then the opaque polygon records by accumulating the net effect of the transmittance of all polygons being sampled in a pixel, and applying the color attributes to the net effect of transmittance, thereby decoupling color from the calculations for determining transmittance.

Abstract: A method for creating a large-scale synthetic environment simulation which can be used in real-time. The method enables real-time viewing, control and interaction of automatically generated, abstract feature models and terrain surface models having multiple levels of detail, while providing correlated multi-sensor viewing and interaction of objects.

Abstract: A method and apparatus for providing an improved area of interest display system by providing a transition zone between a high resolution image being reflected onto and a low resolution image being projected onto a display screen. A combiner surface is provided in the form of a mirror having an all-reflective surface which transitions to an all-transmissive surface. The transition occurs in the form of pixels of highly reflective material which are disposed on the combiner surface using a dithering pattern generated from a modified error diffusion algorithm which minimizes undesired grouping of pixels.

Abstract: An adaptive pixel multisampler generates pixel data for display by using sub-pixel areas to more broadly define the space of a pixel. A sub-pixel area is defined as having a "hole" within it that is occupied by a portion of each of the adjacent sub-pixel areas. This means that while the sub-pixel areas interlock, they do not overlap which would be wasteful of memory space. Accordingly, a pixel is newly defined as extending over a larger area than a standard contiguous pixel definition of the prior art allows. The larger pixel thus provides a wider sampler area which is then used as a means for generating a higher quality anti-aliased image on the display.

Abstract: Images for non-planar display systems are generated using polygon definitions that are pre-distorted using panel shear transforms. Initially, panel shear transforms are generated based on the configuration and orientation of a screen, a projector and a viewer. Polygons defined in model space are mapped to a two-dimensional space and then transformed to a panel space using the panel shear transforms. This transformation technique enables the use of standard two-dimensional rendering processes to scan-convert the polygons.

Abstract: In a multiple-projector concave-screen display system, spacial alignment of images on the screen, is enabled by designating calibration points with retro-reflective dots and illumination markers. The manufacture of the screen involves locating calibration points and depositing the dots with a tool utilizing a rotary mechanism for loading and applying the dots from solenoid actuated pod units. Areas for retro-reflective dots, versus illumination markers, are defined on the basis of reflectance angles between vectors to the screen from a projector and from the screen to a viewer.

Abstract: A geometric processor provides object primitives, as triangles, in graphic display image space to support a dynamic display. The image space is defined by pixels, in turn specified in arrays as spans. In a multi-level scanning operation, primitives are scanned at a first level to locate lapped spans that are lapped by primitives. At a second level, spans are scanned to process pixels that are lapped by primitives. An alternative embodiment discloses three-level scanning in association with parallel pixel processing. Concurrent texturing structure operates along with cache memories.

Abstract: An image texturing system utilizes theme cells to generate terrain image data area-by-area for a dynamic terrain display. The system is effective in flight simulation apparatus, as for training pilots. A memory stores theme maps representing areas of specific terrains, e.g. terrains lying below a flight path. The theme maps are indexed on a square grid pattern and include a feature identification code (FIC) for each grid point to indicate terrain, e.g. forest, water, etc. A selection device controlled by an image generator selects a current theme map and dissects it cell-by-cell as defined by grid points to provide corner-referenced representations for each theme cell. A terrain storage device stores a library of terrain treatment pattern arrays that are derived, for example, from photo data of forest, ocean, or the like.

Abstract: A geometric processor provides object primitives, as triangles, in graphic display image space to support a dynamic display. The image space is defined by pixels, in turn specified in arrays as spans. In a multi-level scanning operation, primitives are scanned at a first level to locate lapped spans that are lapped by primitives. At a second level, spans are scanned to process pixels that are lapped by primitives. An alternative embodiment discloses three-level scanning in association with parallel pixel processing. Concurrent texturing structure operates along with cache memories.

Abstract: The present invention is directed to a simulation system for simulating virtual reality experiences such as for the sport of hang gliding or the like. The simulation system has a stereoscopic and collimated virtual image display, for providing pupil forming simulated images to a rider at a fixed point of reference relative to the stereoscopic display. In the disclosed embodiment, the simulation system comprises a mechanical support structure for suspending the rider in a harness so as to allow freedom of movement. The rider is suspended to face a visual display over a movable control bar coupled to the mechanical support structure. By maneuvering the control bar, riders may view the results of their actions as by a simulated display. The visual display is coupled to the control bar to receive electrical signals indicative of the movements initiated by the riders as they maneuver through a programmed environment.

Abstract: To create a dynamic textured display, images of textured height fields (elevation samples arrayed on a rectangular coordinate grid, as to represent a terrain) are rendered, the system performing an initial pass that re-samples the height-field data into a radial form and a subsequent pass using the radial data to create textured, shaded picture elements (pixels) for an instantaneous field of view. Thus, texturing, shading, blending and scan conversion complete the pixel processing to drive a display unit. The system is particularly applicable to the generation of dynamic perspective images of terrain. The process provides pixel-limited textural resolution in the final image with effective antialiasing of internal and horizontal silhouette edges.

Abstract: A head-mounted projection display system featuring a beam splitter displays a simulated environment to an observer using a light-weight, low-cost, head-mounted projector and a retro-reflective screen. The display system optically co-locates the projector with the observer's eyes for effective use of either curved or flat retro-reflective screens. High screen gain achieved by the head-mounted projection display system makes inexpensive projector sources such as a cathode ray tube feasible. An alternative head-mounted display system also incorporating beam splitters produces an unlimited horizontal field of view, but with limited binocular overlap, while using multiple head-mounted image sources for each eye. A method of providing the head-mounted display system also is disclosed.

Abstract: In a computer graphics system, wherein three-dimensional data is processed to produce dynamic displays, two-dimensional texture images are sequentially mapped onto objects in the display to form movable animated figures. Objects receiving two-dimensional texture maps may be transparent and take specific forms for certain effects, for example, intersecting planes, stamps, moving objects, and so on. Texture maps are composed utilizing a variety of source devices including: computer graphics systems, video cameras, two-dimensional scanners.

Abstract: Front end processors in a graphics architecture execute parallel scan conversion and shading to first process individually assigned primitive objects for providing update pixels. A crossbar accommodates data rearrangement whereby parallel pixel processors with associated memory capabilities (frame buffer banks) perform visibility and blending operations on predetermined sequences of update pixels to provide display pixels. The pixel processors identify with sequences of pixels in the display in patterns designed to equalize processor loads for pixels located along scan lines or distributed over an area. Specific distribution criteria are disclosed for patterns. One form of pixel processor organization incorporates a distributed frame buffer with FIFO memory and control stacks. Display pixels are received by a multiplexer to supply a digital-analog connector with display data in raster sequence.

Abstract: Primitive data in the form of defined lines for a computer graphics display is processed as by interpolating triangles, as during scan conversion, and by treating lines as triangle edges. An offset point is selected, e.g. offset perpendicularly from the line midpoint a distance of one-half the line length to define a triangle vertex along with the line endpoints. The resulting triangle is interpolated for example as with barycentric coordinates. Accordingly, the line may be interpolated, e.g. shaded, as though it were an edge of the defined triangle. For lines, sample points are coerced to lie on the triangle edge.

Abstract: Barycentric coordinates are determined using data readily available in computer graphics systems and defining polygons in world space so as to interpolate such polygons with regard to pixels selected by scan conversion. The barycentric coordinates are employed to interpolate the polygons, for example to accomplish smooth shading or texture mapping. The process of the system involves defining primitive data (e.g. polygons) in a space not subject to nonlinear distortion (e.g. world space), transforming select primitive data to a space that is subject to nonlinear distortion, calculating in the space subject to nonlinear distortion (e.g. screen space) a set of areas (e.g. pixels) within a defined primitive (e.g.

Abstract: A graphics system provides color image displays including a low resolution, wide field background and a contained high resolution area of interest, by projecting three component color images at wide angle, one of which (green) is blanked at the area of interest and is filled by a separate projection of a high resolution image (green). Simulator apparatus utilizing the graphics system responsively actuates a vehicle platform supplying data signals to an image generator apparatus whereby the area of interest may be variously displaced responsive to movements by of the viewing platform.

Abstract: For a raster-scanned, video display apparatus, individual pixel display data is stored in a double image frame buffer. A valid count buffer then holds a count for each pixel. Current valid counts are stored, as at times of image buffer updating which updating includes storing display data changes and a fraction of the total display (background). At times of display, current counts from the count buffer are tested against valid counts as stored for each pixel in the valid count buffer to determine the selection of display data from the image frame buffer or alternate background data. A window frame buffer resolves the display into windows that are accommodated by the system with valid counts for each window.

Abstract: A task status word (TSW) is created for each task indicating, the instant location of the task, its priority and a record of synchronizing signals. Task status words are accessible from an addressable memory section for delivery to a TSW register. From the TSW register, a selected TSW effects control functions to synchronize tasks in different processors or computational units as well as input-output processors. A physical memory manager locates TSWs in response to signals, then checks the location of the task and the nature of the signal to determine signal routing to a processor. If a task is not in a processor, an interrupt manager resolves priority and signal significance indicated by the TSW to determine an interrupt.