Abstract: A method of producing a multi-resolution mesh is provided. A vertex array and a face array are constructed, wherein the vertex records and face records are ordered in the respective arrays by resolution. These arrays therefore comprise ordered vertices and faces to be added or removed for each incremental change in resolution. A vertex update record associated with each vertex contains face update records which specify what existing faces must be updated when adding or removing the vertex, and contains a new faces record indicating the number of faces from the face array to be added to or deleted from the mesh when adding or removing the vertex.

Abstract: A virtual reality system surveys a real-world environment, generates 3D data that defines the real-world environment, renders a virtual 3D environment using the 3D data, retrieves a virtual object from a database comprised of pre-stored virtual objects, renders the virtual object in the virtual 3D environment, and re-positions the virtual object in the virtual 3D environment.

Abstract: A computer creates a digital model of a 3D surface to be rendered. The computer obtains an initial digital model of the 3D surface and identifies base triangles in the initial model. Each base triangle is subdivided into a plurality of subdivision triangles. The computer assigns identifying labels to the subdivision triangles to indicate their positions in the base triangles. Thereafter, the computer further subdivides the digital model; for example by applying a computer-implemented test to a first identifying label corresponding to first subdivision triangle to automatically derive a second identifying label corresponding to a second subdivision triangle in a different base triangle and sharing an edge with the first subdivision triangle, using the first and second identifying labels to retrieve information about the first and second subdivision triangles, and then using this information to subdivide the first subdivision triangle into smaller triangles.

Abstract: A method of producing a multi-resolution mesh is provided. A vertex array and a face array are constructed, wherein the vertex records and face records are ordered in the respective arrays by resolution. These arrays therefore comprise ordered vertices and faces to be added or removed for each incremental change in resolution. A vertex update record associated with each vertex contains face update records which specify what existing faces must be updated when adding or removing the vertex, and contains a new faces record indicating the number of faces from the face array to be added to or deleted from the mesh when adding or removing the vertex.

Abstract: An arrangement is provided for compressing speech data. Speech data is compressed based on a phoneme stream, detected from the speech data, and a delta stream, determined based on the difference between the speech data and a speech signal stream, generated using the phoneme stream with respect to a voice font. The compressed speech data is decompressed into a decompressed phoneme stream and a decompressed delta stream from which the speech data is recovered.

Abstract: Portable virtual reality is disclosed. A digital camera captures an input video stream comprising video frames that carry information about a surrounding environment limited by a field of view of the camera. The input video stream is processed by a handheld computer coupled to the camera. Parameters that define a rendered scene of a virtual environment are adjusted based upon motion parameters extracted from the input video stream by the handheld computer during the processing.

Abstract: Camera driven virtual workspace management is disclosed. A digital camera captures an input video stream comprising images of a surrounding environment limited by a field of view of the camera. The input video stream is processed by a handheld computer coupled to the camera. Parameters that define a partial view of a virtual workspace are redefined based upon motion analysis of the input video stream performed by the handheld computer during the processing.

Abstract: In rendering a 3D surface, a computer obtains an initial digital data set that defines a base mesh coarsely approximating the 3D surface, where the base mesh includes vertices connected to form 2D faces. The computer subdivides the 2D faces of the base mesh one or more times to form one or more subdivision meshes, where each subdivision mesh more closely approximates the 3D surface than each preceding mesh, and where each subdivision mesh includes more vertices than each preceding mesh. For each subdivision mesh, the computer applies a computer-implemented algorithm to the vertices in the subdivision mesh to project the vertices onto a limit surface that represents the actual shape of the 3D surface, where the projected vertices define a projected surface. The computer then renders an image of the projected surface for the subdivision mesh instead of rendering an image of the subdivision mesh itself.

Abstract: Generating a multi-resolution mesh from an original mesh representing a scene or object is achieved by collapsing edges of the original mesh in a first order defined by a surface area error metric to produce a modified mesh, and collapsing edges of the modified mesh in a second order defined by a combination quadric and surface area error metric to produce a multi-resolution mesh. The transition from using the surface area error metric to the combination of the surface area error metric and the quadric error metric occurs when a cost for removing one of the edges from the mesh as determined by the surface area error metric exceeds a threshold. A volume error metric may be used in conjunction with the surface area error metric in collapsing edges of the mesh to allow an edge collapse only when the volume error metric for the edge indicates collapsing the edge will not substantially alter the shape of the mesh.