500 results about "Triangle mesh" patented technology

The present invention relates to a method of intelligent 2D and 3D object and scene modeling, transformation and manipulation and more particularly this invention relates to the field of computer modeling, virtual reality, animation and 3D Web streaming. The method uses attributed hypergraph representations (AHR) for modeling, transforming and manipulating objects. From one or more 2D views of a 3D object or scene, range information is first computed and then a triangular mesh model is constructed. The data structure is designed to handle the transformations on the representation corresponding to movements and deformations of the object. In an attributed hypergraph, the attributes associated with the hyperedges and the vertices facilitates modeling of various shapes with geometrical, physical or behavior features. As a hierarchical and generic representation, AHR enables pattern matching, recognition, synthesis and manipulation to be carried out at different resolution levels on different subsets depending on the context. Symbolic computation on knowledge represented in the format of attributed hypergraphs becomes straightforward. Given the features of a 3D object or scene, the procedure of constructing the AHR corresponds to the concept of functor in category theory, which maps one category to another one. The transformations of AHR are in the form of a set of operations defined on attributed hypergraphs, which stand for the motions and deformations of the object. This representation is applied to various modeling and manipulation tasks on 3D objects. The process of motion analysis of a 3D object is the task of extracting a sequence of AH operators from the AHR of the object. A 3D scene can be modeled by AHR and then altered / augmented with other 3D models, by which an augmented reality can be built. Given the AHR's of two different 3D shapes, 3D morphing may be accomplished by matching the two AHR's and then mapping the difference to a sequence of AH operators. Model based animation of an object can be accomplished by applying a set of AH operators to its AHR. The AHR method forms a data compression system for efficient web streaming over the Internet.

A method for compressing 3D geometry data that is capable of compressing both regularly tiled and irregularly tiled surfaces is disclosed. In one embodiment, the method comprises examining 3D geometry data to detect the presence of regularly tiled surface portions. The 3D geometry data is then compressed by: (1) encoding any regularly tiled surface portion using a first encoding method, and (2) encoding any irregularly tiled surface portions using a second encoding method, wherein the second encoding method is different from the first encoding method. The first encoding method may encode the regularly tiled surface portions as vertex rasters, while the second method may encode the irregularly tiled surface portions by geometry compression using a generalized triangle mesh.

The present invention provides a three-dimensional surface generation method that directly and efficiently generates a three-dimensional surface of the object surface from multiple images capturing a target object.The three-dimensional surface generation method of the present invention sets one image as a basis image from multiple images obtained by capturing the target object from different viewpoint positions and sets other images as reference images, and then generates two-dimensional triangle meshes on the basis image. Next, the method of the present invention sets a distance between a vector whose elements are pixel values of an image obtained by deforming the reference image by a homography determined by an all-vertices depth parameter of meshes and camera parameters and a vector whose elements are pixel values of the basis image, as a term of a cost function, and computes the all-vertices depth parameter that a value of the cost function becomes smallest by iteratively performing the computation of the small variation of the all-vertices depth parameter and the update of the current value of the all-vertices depth parameter by using an optimization method that sets the multiple images, the camera parameters and the initial value of the all-vertices depth parameter as inputs till a predetermined condition is satisfied.

A 3D rendered image of a radar-scanned terrain surface is provided from a radar return signal from the surface, wherein the return signal includes data indicative of azimuth, elevation, and range of a radar-illuminated area of the surface. The data are processed for transformation into X, Y, and Z coordinates. The X and Y coordinates corresponding to each illuminated area are triangulated so as to create a mesh of triangles representing the terrain surface, each of the triangles in the mesh being defined by a vertex triplet. 3D imaging information (grey scale shading and / or coloring information) is added to each triangle in the mesh, based on the amplitude of the radar return signal from the coordinates represented by each vertex in the triplet and the value of the Z coordinate at each vertex, so as to form the 3D rendered image.

The invention discloses a block model building method for complex geological structure, and relates to the geological field of three-dimension modeling comprising the following steps: a, triangular meshing description is carried out on planes or fault planes; b, after step a, level intersection in block modeling for complex geological structure is converted into triangle intersection in space, whether the two triangles are intersected is judged, points of intersection are found from the two intersected triangles, and a line of intersection is obtained by connecting the points of intersection; c, geometric consistency and topological consistency are carried out on inside of each intersected triangle; d, after step c, enclosing block is extracted to obtain an interface formed by peripheral sides of the enclosing block, and is defined geological attribute to form three dimension model block. The method in the invention completely solves the problems of three dimension model input and blocking in complex geological regions, avoids using equations set with high solving difficulty and calculated amount, and is simple and practical.

A printed page tag encoder has an input at which to receive a tag structure template, an input at which to receive fixed data bits, an input at which to receive variable data bit records, and a tag dot generator outputting single bits depending on position in the tag defined by the tag structure template and said fixed and said variable data. The encoder additionally has a redundancy encoder for optionally encoding said fixed and / or said variable data. The redundancy encoder utilizes Reed-Solomon encoding. Tags are placed regularly on a page and ideally in a triangular grid.

Embodiments of the invention involve forming a prismatic grid and solving a convection-diffusion problem using the prismatic grid and mixed finite element analysis. The prismatic grid may be formed by providing a triangular mesh on a plane of a model. The mesh is then coarsened to make cells that are less desirable larger. The coarsened grid is then projected to form the prismatic grid. Each cell of the grid is then assigned a plurality of degrees of freedom. Mixed finite element analysis of the grid produces a matrix, which is then solved to yield a solution to the convention-diffusion problem.

Scheme for improving the quality of cloth simulation by providing a good dynamic “wrinkled” look to the cloth as it moves. The simulated area of each of the triangles in the triangle mesh is compared with the original area of the triangle to determine how much it got compressed or stretched during animation. This comparison is then used as a basis for altering the lighting of the pixels representing the triangles in order to improve the appearance of the wrinkles in the cloth. The lighting of each pixel is altered by altering a surface normal of the pixel using a value obtained from each of one or more normal maps. Normal maps are selected by using wrinkle ratios that are calculated based on the above mentioned comparisons.

The invention discloses a nonrigid medical image registration method based on self-adapting triangular meshes in the field of image processing technology. In the method, the thought of graded registration is adopted to implement overall registration on a standard image to be registered and a reference image; then the angular points of the images are used to restrain the interested regions of the overall registration image and the reference image to generate irregular triangular meshes, and generate triangular units with smaller shapes and more quantity at places with larger deformation in theinterested region of the image; the triangular meshes generated by the triangular units with larger shapes and less quantity at places with smaller deformation in the interested region of the image are changed according to the changes of the image contents; and finally, the thought of near-rigid registration is used for realizing local accurate registration of the images. The nonrigid medical image registration method based on self-adapting triangular meshes can effectively improve the accuracy of nonrigid medical image registration and enhance the noise resisting capacity of registration.

The invention concerns the refinement of a triangular mesh representing a three-dimensional object (3D), said mesh consisting of an arrangement of vertices and triangular surfaces, each defined by three references to the vertices which it links, and having three edges each linking two of said vertices. The invention is characterized in that said method comprises a step which consists in selecting at least a region of interest, said mesh refinement being carried out locally on at least one region of interest.

An apparatus for generating 3D geographical models includes a processor and memory storing executable computer program code causing the apparatus to at least perform operations including removing points of a cloud depicting vertical structures in meshes of triangles detected in an area corresponding to a set of 3D points responsive to identifying triangles on vertical structures. The triangles include vertices corresponding to geocoordinates. The program code further causes the apparatus to interpolate non-vertical structures of triangles to generate a dense cloud of points. The program code further causes the apparatus to downward project delineated points of segmented rooftops to closest points of a ground to generate 3D polygonal models depicting geographical objects. The program code further causes the apparatus to generate texturized objects responsive to mapping triangle locations to the 3D polygonal models and assign texture to vertical structures and rooftops. Corresponding methods and computer program products are also provided.