Abstract: Techniques and tools for mesh processing are described. For example, a multi-chart geometry image represents arbitrary surfaces on object models. The multi-chart geometry image is created by resampling a surface onto a regular 2D grid, using a flexible atlas construction to map the surface piecewise onto charts of arbitrary shape. This added flexibility reduces parameterization distortion and thus provides greater geometric fidelity, particularly for shapes with long extremities, high genus, or disconnected components. As another example, zippering creates a watertight surface on reconstructed triangle meshes. The zippering unifies discrete paths of samples along chart boundaries to form the watertight mesh.

Abstract: Systems and methods for discontinuity edge overdraw are described. In one aspect, a polygonal mesh is rendered to produce a computer-generated image. The image exhibits aliasing at its discontinuity edges. The discontinuity edges are sorted prior to overdrawing. The discontinuity edges are overdrawn as anti-aliased lines to reduce the aliasing.

Abstract: Techniques and tools for mesh processing are described. For example, a multi-chart geometry image represents arbitrary surfaces on object models. The multi-chart geometry image is created by resampling a surface onto a regular 2D grid, using a flexible atlas construction to map the surface piecewise onto charts of arbitrary shape. This added flexibility reduces parameterization distortion and thus provides greater geometric fidelity, particularly for shapes with long extremities, high genus, or disconnected components. As another example, zippering creates a watertight surface on reconstructed triangle meshes. The zippering unifies discrete paths of samples along chart boundaries to form the watertight mesh.

Abstract: A method and a system are presented to generate automatically factored approximations for arbitrary Bidirectional Reflectance Distribution Functions (BRDFs). The method presented extends previous work to include a search over a space of 4D to 2D projections. Each set of projections defines a set of factors, which in turn defines an approximation error. This error is minimized using a conventional multi-dimensional search algorithm. A new representation for the projection functions is presented that allows efficient searching and enables the construction of a full approximation of a BRDF from the set of its optimal factors and the computation of reflectance values for arbitrary viewing angles using the function's full approximation.

Abstract: Reduction of aliasing artifacts along discontinuity edges of a rendered polygon mesh is achieved by overdrawing the edges as antialiased lines. The discontinuity edges are oriented consistently and blended as they approach silhouettes in the mesh to avoid popping at the edge, thereby achieving a temporal smoothness at the silhouettes. This temporal smoothness is balanced with a competing desire to maintain spatial sharpness by utilizing an asymmetric blending technique. To further improve results, the discontinuity edges can be sorted by depth prior to overdrawing them. These processes are effective at reducing the temporal artifact known as “crawling jaggies”.

Abstract: A method and a system are presented to generate automatically factored approximations for arbitrary Bidirectional Reflectance Distribution Functions (BRDFs). The method presented extends previous work to include a search over a space of 4D to 2D projections. Each set of projections defines a set of factors, which in turn defines an approximation error. This error is minimized using a conventional multi-dimensional search algorithm. A new representation for the projection functions is presented that allows efficient searching and enables the construction of a full approximation of a BRDF from the set of its optimal factors and the computation of reflectance values for arbitrary viewing angles using the function's full approximation.

Abstract: Reduction of aliasing artifacts along discontinuity edges of a rendered polygon mesh is achieved by overdrawing the edges as antialiased lines. The discontinuity edges are oriented consistently and blended as they approach silhouettes in the mesh to avoid popping at the edge, thereby achieving a temporal smoothness at the silhouettes. This temporal smoothness is balanced with a competing desire to maintain spatial sharpness by utilizing an asymmetric blending technique. To further improve results, the discontinuity edges can be sorted by depth prior to overdrawing them. These processes are effective at reducing the temporal artifact known as “crawling jaggies”.

Abstract: A method and computer product for rendering real-time three-dimensional images on a display based on view manipulation of prestored depth images in a global coordinate space. First, a layered depth image is generated from multiple depth images based on a predetermined display viewpoint. If the determined viewpoint is within a predetermined threshold of the layered depth image, the generated layered depth image is warped based on the determined display viewpoint, pixels from the layered depth image are splatted onto the warped image, and an output image is generated and displayed based on the splat pixels. If the determined viewpoint is outside the predetermined threshold of the previously generated layered depth image, a next closest layered depth image is generated. If the next closest layered depth image is not fully generated, the previously generated layered depth image is used to generate an output image.

Abstract: A computer-based method and system for digital 3-dimensional imaging of an object which allows for viewing images of the object from arbitrary vantage points. The system, referred to as the Lumigraph system, collects a complete appearance of either a synthetic or real object (or a scene), stores a representation of the appearance, and uses the representation to render images of the object from any vantage point. The appearance of an object is a collection of light rays that emanate from the object in all directions. The system stores the representation of the appearance as a set of coefficients of a 4-dimensional function, referred to as the Lumigraph function. From the Lumigraph function with these coefficients, the Lumigraph system can generate 2-dimensional images of the object from any vantage point. The Lumigraph system generates an image by evaluating the Lumigraph function to identify the intensity values of light rays that would emanate from the object to form the image.