California Institute of Technology

Google Inc.

Lucent Technologies Inc.

Alcatel Lucent

Princeton University

Igor V Guskov

Wim Sweldens

Peter Schröder

Andrei Khodakovsky

Emil Constantin Praun

Brian Edmond Brewington

Tushar Udeshi

Morten Just Petersen

Mark A Limber

Costa Touma

Peter Schroeder

Paul Steven Strauss

Kong Man Cheung

Peter Hamel

Systems and methods for ranking geographic features in a geographic information system are provided. In particular, geographic features can be assigned ranking scores based on characteristics of viewsheds associated with the geographic features. In particular, characteristics of a viewshed associated with a geographic feature can be analyzed to assess the visibility of the geographic feature. A ranking score can be assigned to the geographic feature based on the characteristics of the viewshed. The ranking score can be used prioritize information in a geographic information system.

System and method for ranking geographic features using viewshed analysis

An irregular connectivity mesh representative of a surface having an arbitrary topology is processed using a non-uniform relaxation procedure. The non-uniform relaxation procedure minimizes differences between vectors normal to faces of pairs of triangles having a common edge and located within a designated neighborhood of a given vertex. The relaxation procedure may be used to construct subdivision and pyramid algorithms for performing processing operations such as upsampling, downsampling and filtering on irregular connectivity meshes. The signal processing algorithms may be utilized in applications such as smoothing, enhancement, editing, texture mapping and compression.

Non-uniform relaxation procedure for multiresolution mesh processing

Embodiments relate to carving three dimensional models of buildings out of larger models of city blocks to make way for more detailed models. In accordance with one aspect of the invention, a computer-implemented method for carving a building from a first three-dimensional model is described. The first three-dimensional model may represent a city block. The three-dimensional model may include a plurality of polygons which represent one or more buildings in a three-dimensional environment. One or more polygons are identified as a portion of a roof, and roof portions that are not discontinuous are combined in roof meshes. Based on a roof mesh, a three-dimensional volume portion of a three-dimensional model is determined, which may represent a first building. The first building representation may then be carved from the three-dimensional model.

Carving buildings from a three-dimensional model, and applications thereof

A proxy based approach for generation of level of detail. In an embodiment, the present invention generates level of detail using a proxy based approach by (1) receiving a three dimensional polygon mesh with textures; (2) extracting a set of masking primitives above a first threshold from the three dimensional polygon mesh; (3) calculating a set of proxy planes, where the calculation includes associating each proxy plane with at least one of the masking primitives; and (4) optimizing the set of proxy planes.

Proxy based approach for generation of level of detail

A method of forming a hybrid mesh representation of an object surface is provided, along with the hybrid mesh representation and data structures corresponding to various polygons in the hybrid mesh representation. The hybrid mesh representation comprises a base mesh and one or more higher level meshes. At least one of the higher level meshes representing a patch is an irregular mesh. The method of forming the hybrid mesh representation comprises the steps of forming a base mesh, and then forming one or more higher level meshes from the base mesh through one or more regular refinement operations in combination with at least one irregular operation.

Hybrid meshes

A special set of normal meshes is defined where errors and residuals will also be along a direction that minimizes the error in coding. These normal meshes can be used to model a three dimensional surface.

Use of normal meshes in three-dimensional imaging

Growing community of inventors

Ann Arbor, MI, United States of America

Igor V Guskov