1556 results about "Mesh model" patented technology

System and method for constructing a 3D model of an object based on a series of silhouette and texture map images. In the exemplary embodiment an object is placed on a rotating turntable and a camera, which is stationary, captures images of the object as it rotates on the turntable. In one pass, the system captures a number of photographic images that will be processed into image silhouettes. In a second pass, the system gathers texture data. After a calibration procedure (used to determine the camera's focal length and the turntable's axis of rotation), a silhouette processing module determines a set of two-dimensional polygon shapes (silhouette contour polygons) that describe the contours of the object. The system uses the silhouette contour polygons to create a 3D polygonal mesh model of the object. The system determines the shape of the 3D model analytically-by finding the areas of intersection between the edges of the model faces and the edges of the silhouette contour polygons. The system creates an initial, (rough) model of the 3D object from one of the silhouette contour polygons, then executes an overlaying procedure to process each of the remaining silhouette contour polygons. In the overlaying process, the system processes the silhouette contour polygons collected from each silhouette image, projecting each face of the (rough) 3D model onto the image plane of the silhouette contour polygons. The overlaying of each face of the (rough) 3D model onto the 2D plane of the silhouette contour polygons enables the present invention to determine those areas that are extraneous and should be removed from the (rough) 3D model. As the system processes the silhouette contour polygons in each image it removes the extraneous spaces from the initial object model and creates new faces to patch “holes.” The polygonal mesh model, once completed, can be transformed into a triangulated mesh model. In a subsequent step, the system uses a deterministic procedure to map texture from the texture images onto the triangles of the 3D mesh model, locating that area in the various texture map images that is “best” for each mesh triangle.

A method for determining the risk of rupture of a blood vessel using an appropriate set of 2-D slice images obtained by scanning the blood vessel, the method comprising: generating a mesh model of the blood vessel using the set of 2-D slice images; conducting finite element stress analysis on the mesh model to calculate the level of stress on different locations on the mesh model; and determining the risk of rupture of the blood vessel based on the calculated levels of stress on different locations on the mesh model.

Simulation systems, manufacturing systems, software products and controllers are provided with multi-scale modeling in which a coarse mesh and a fme mesh that models a stimulus are decoupled. The fine mesh can be moved within the coarse mesh with a cut and paste operation. The coarse mesh is updated by sparsely propagated effects through the coarse mesh. Simulations of the invention can be conducted in real-time, and be used as controllers in manufacturing systems, such as additive manufacturing systems. A number of efficient methods are provided for solving meshing determinations that arise from movement of a stimulus modeled within a fine mesh.

The invention relates to an unmanned aerial vehicle aerial photography sequence image-based slope three-dimension reconstruction method. The method includes the following steps that: feature region matching and feature point pair extraction are performed on un-calibrated unmanned aerial vehicle multi-view aerial photography sequence images through adopting a feature matching-based algorithm; the geometric structure of a slope and the motion parameters of a camera are calculated through adopting bundle adjustment structure from motion and based on disorder matching feature points, and therefore, a sparse slope three-dimensional point cloud model can be obtained; the sparse slope three-dimensional point cloud model is processed through adopting a patch-based multi-view stereo vision algorithm, so that the sparse slope three-dimensional point cloud model can be diffused to a dense slope three-dimensional point cloud model; and the surface mesh of the slope is reconstructed through adopting Poisson reconstruction algorithm, and the texture information of the surface of the slop is mapped onto a mesh model, and therefore, a vivid three-dimensional slope model with high resolution can be constructed. The unmanned aerial vehicle aerial photography sequence image-based slope three-dimension reconstruction method of the invention has the advantages of low cost, flexibility, portability, high imaging resolution, short operating period, suitability for survey of high-risk areas and the like. With the method adopted, the application of low-altitude photogrammetry and computer vision technology to the geological engineering disaster prevention and reduction field can be greatly prompted.

A system and method for design of experiments (DOE) using direct surface manipulation of a mesh model. The method includes the steps of selecting a geometric model in a computer-aided design (CAD) format, converting the geometric model into a mesh model and evaluating the mesh model using a computer-aided engineering (CAE) analysis. The method also includes the steps of determining whether to continue generating the design of experiments response, and modifying a surface of the mesh model by varying a predetermined parameter, wherein the surface is modified using direct surface manipulation (DSM), the mesh model is updated and the updated mesh model is used in continuing generating the design of experiments response, if determined to continue the design of experiments. The method further includes the steps of using the results of the CAE analysis for the design of experiments.

The invention discloses an implementation method of skinned skeletal animation. The implementation method comprises the following steps: A, constructing a skeleton model and a skinned mesh model which constitute a role model; B, determining a skeleton which influences the mesh vertexes on the skinned mesh model, and determining the influence weight according to a geometrical relationship and a physical relationship between the skeleton and the vertexes; C, carrying out calculus of interpolation between each two adjacent key frames according to a key frame sequence of skeleton movement, which is stored in a role model file, and determining new position and new orientation of each skeleton at certain moment; and D, calculating new position and new orientation of each vertex under a world coordinate system according to skeleton index and corresponding influence weight which influence each vertex and are stored in each vertex on the skinned mesh model, and thus achieving skinned skeleton animation. According to the implementation method disclosed by the invention, the joint problem in skeletal animation is solved, the effect is real and vivid, and is more flexible compared with that of vertex animation, and little memory space is occupied while a favorable animation effect is finished; the skinned skeletal animation can be constructed more easily and rapidly.

The invention relates to a subsurface flow simulating and predictive analysis method which comprises the following steps of: dynamically observing and collecting groundwater date of a mining area, integrating the groundwater data into a graphic workstation by utilizing a data engine, automatically establishing a finite element mesh model of the dynamic water level of each water layer, and determining parameter partitions and corresponding parameter values so as to realize the dynamic analog of water level of the water layer and the simulation of groundwater migration; and carrying out the simulation of a groundwater seepage field and the dynamic and real-time simulation of aquifer in designed software and hardware environments, and carrying out interactive analysis, prediction and evaluation on various models in the VR environment and the WEB environment by using tools such as interactive operation, information inquiry, and the like. The method can provide the scientific basis of reasonably developing and utilizing water resources for the future development and the evolution tendency of groundwater resources, and achieves low overall cost, easy popularization and use as well as flexible and reliable operation.

The invention relates to a method for analyzing facial expressions on the basis of motion tracking, in particular to a technique for face multi-feature tracking and expression recognition. The method comprises the following steps: pre-processing an inputted video image, and carrying out the face detection and face principle point location to determine and normalize the position of the face; modeling the face and expressions by using a three-dimensional parametric face mesh model, extracting the robust features and tracking the positions, gestures and expressions of the face in the inputted video image by combining the online learning method, so as to achieve the rapid and effective face multi-feature tracking; and taking the tracked expression parameters as the features for expression analysis; and carrying out the expression analysis by using an improved fuzzy clustering algorithm based on Gaussian distance measurement, so as to provide the fuzzy description of the expression.

A 3D modeling system for automatically generating fully-textured 3D models of objects from a sequence of images taken around the objects is disclosed. There are several processes developed to facilitate the operation of the 3D modeling system by an ordinary skilled person. One of the processes is the automatic calibration of a camera using only a portion of a calibration disc to essentially provide a larger effective field of view of the camera. Another process is a space carving process that subdivides volumetric cells recursively to fit to a 3D object using a tree structure that encodes the entire process. Still another process is a 3D mesh model generation process that begins with the tree structure and generates self-constraint and interconnected triangles, in a sense that all triangles intersect with each other either not at all or at common boundary faces, to represent the shape of the 3D object. Yet still another process is a textured patch process that provides a useful mechanism for a user to edit and modify a fully-textured 3D model in a desired manner by the user.

The invention provides a method for tracing the position and pose of a 3D human face in a video sequence. In the method, based on the principal component analysis, by using a deformable 3D grid model, minimizing the distance between a key point on the grid model and a corresponding key point on an input image, the model can fit the head figure of a user; the human face texture can be obtained by using the 3D model at an initial phase, so as to render human face images under different poses; the feature points can be selected in the rendered images, and a corresponding position can be searched on the input image; the matching faults can be removed by using a random sampling mode; then, mode pose changed parameters can be estimated according to the corresponding relationship between the feature points, so as to update a hypothetical state; finally, a distance between the rendered image and an actual image can be calculated by using the average normalized correlation algorithm, so as to calculate a hypothetical weight. Experiments show that the method can effectively trace the pose of the 3D head in the video.

The invention relates to a rapid generation method for facial animation, belonging to the image processing technical field. The method comprises the following steps: firstly detecting coordinates of a plurality of feature points matched with a grid model face in the original face pictures by virtue of an improved active shape model algorithm; completing fast matching between a grid model and a facial photo according to information of the feature points; performing refinement treatment on the mouth area of the matched grid model; and describing a basic facial mouth shape and expression change via facial animation parameters and driving the grid model by a parameter flow, and deforming the refined grid model by a grid deformation method based on a thin plate spline interpolation so as to generate animation. The method can quickly realize replacement of animated characters to generate vivid and natural facial animation.

A finite element pre processing method for reconstructing a three-dimensional entity model comprises the steps that first, a material object is scanned so that point cloud data can be acquired; second, the point cloud data are imported to 3-matic software, and the position of the model is adjusted; third, the point cloud data are de-noised and sampled; fourth, three-dimensional reconstructing of the point cloud data is performed through a computer, wherein the point cloud data are packaged so that a surface mesh model can be generated; fifth, thin wall characteristic analysis is performed on the model so that a basic model structure can be known; sixth, three-dimensional repair is performed on model meshes, so that the edges of the model are matched with the defect contour of the material object; seventh, the model is redesigned as required, and thus the structure of the model can be more reasonable and meet the design requirement; eighth, the meshes of the redesigned model are partitioned again; ninth, a volume mesh is generated, material attributes are added, and the new model is saved in the format through which finite elements can be directly analyzed; tenth, finite elements are analyzed. Through the method, the scanned data processing time is shortened and FEA/CFD pre processing time are shortened, and optimal design of the model can be conveniently performed.

An apparatus, a method and a program segment mesh model data into analytic surfaces based on robust curvature estimation and region growing by extracting, from mesh model data, analytic surface regions (planar, cylindrical, conical, spherical and toric surface regions) and by automatically recognizing fillet surface regions, linear-extrusion surface regions and surface regions of revolution from the extracted regions and edges. The apparatus, method and program input mesh model data, find sharp vertices in the mesh model data, calculate principal curvatures at each non-sharp vertex, create, from the calculated principal curvatures, seed regions each being considered to belong to an analytic surface region and including a set of linked vertices, extract analytic surface regions by growing the seed regions, recognize fillet surface regions, linear-extrusion surface regions and surface regions of revolution in the extracted analytic surface regions, and output information concerning the extracted analytic surface regions and information concerning the recognized regions.

A method of determining the fatigue life of a welded structure, including the steps of: creating a 3D coarse mesh model of the welded structure to be analyzed; analyzing the coarse mesh model using an FEA model to generate FEA data; identifying a critical stress location on the coarse mesh model having a through thickness stress distribution, based on the FEA data; post processing the FEA data in the middle portion of the through thickness stress distribution while excluding the through thickness stress distribution near the edges of the identified critical stress location to determine a peak stress; and determining a fatigue life of the welded structure at the identified critical stress location, dependent on the determined peak stress.

Programmatic extraction and management of solid and surface modeling parameters from raw 3D scan data is discussed. An automated process reads raw 3D scan data and works in communication with a CAD system able to perform CAD part modeling. The user is provided with an automatic function to segment a mesh model (formed from the raw 3D scan data) into dozens of mesh regions. A graphical user interface is provided which enables a user to choose a type of the design intent along with the mesh regions from which the design intent is calculated. Each design intent is represented in a vector, a plane or a poly-line depending upon the type of design intent. In response to a user demand for the parameters of a modeling feature, a best approximation of the requested parameter value is calculated by processing the raw 3D scan data using a set of functions.

The invention relates to a three-dimensional model reconstruction method of tree point cloud data based on partition and automatic growth, comprising the following steps: preprocessing; estimating the main curvature of point cloud; partitioning data according to the main curvature; calculating a framework of a principal branch of branches by the partitioned point cloud belonging to a branch part;leading from the framework of the principal branch of the branches to generate twigs of the branches by the partitioned point cloud belonging to a leaf part; and generating a branch mesh model and adding a leaf model at the ends of the twigs of the branches. In the method, the three-dimensional reconstruction model which is faithful to original entities can be obtained by means of the scanning data of a laser scanner; the reconstruction model of the tree point cloud data can be obtained based on data partition and growth of the twigs of the branches, thus the method has simple algorithm and accurate calculation result; and the calculation result has important application value in the fields such as virtual reality, computer games, natural scene simulation, urban landscape design, film production, three-dimensional reconstruction of trees, agriculture and forestry measurement and the like.

The name of the invention is 'system for fully automatically reconstructing foot-type three-dimensional surface from a plurality of images captured by a plurality of cameras simultaneously'. The invention relates to a system for fully automatically reconstructing foot-type three-dimensional surface from a plurality of images, comprising the following main steps of: firstly carrying out statistical analysis on a shoe-tree sample set so as to obtain the statistical deformation model; arranging the imaging environment; obtaining the calibrated template and the image of the human foot by a plurality of cameras; deforming statistical model, and fitting the foot type image so as to obtain the initially estimated model and generate the sparse grid model; and iterating to finely divide the grid model, wherein the image characteristic points from each image are divided in each turn of iteration, the plane characteristic point is matched with the space point, and the grid model is subdivided by using the spatial characteristic point; and finally obtaining the foot type model consistent with the target object. In the invention, a mark point is unnecessary to be set on the foot, and a high-precision laser measurement device is unnecessary; the camera and the computer are only used, and the shutter imaging time and the calculation processing time are only required. The system has fast speed, and can be widely applied to the condition for the three-dimensional reconstruction of the biological skin with relatively low precision request.

The invention discloses a method for 3D reconstruction and texture generation from single-view face based on multi-task learning, belonging to the computer vision field. The method comprises the following steps of: selecting a special viewpoint for rendering a three-dimensional human face model; generating depth map and texture map as truth value data from special viewpoint; designing an integrated learning and coding network based on feature sharing of depth information and texture information; designing the branch decoding network to recover the depth map from the shared features, and recovering the depth map, designing the mutual information with shared features as latent variables to maximize the generation of antagonistic network, and restoring the texture unwrapping map, adjusting the proportion of each task loss function and training the model; interpolating the depth map and using texture map to reconstruct the 3D face mesh model with texture details. The invention utilizes multi-task learning to carry out single-view face three-dimensional reconstruction, texture generation and style migration, and has the advantages of high speed, low cost and the like.

A method is disclosed for calibrating a mathematical model of a component using prototype full-field experimentally collected deformation/strain data. Specifically, the method involves obtaining actual experimental field data using strain sensitive coating material and then mapping said data on a CAD mesh model. The analytical mesh model is then compared to a finite element model that is based on theoretical values referred to as boundary conditions. The finite element model boundary conditions are then calibrated to reflect the values derived from the experimental field measurements. Once calibrated, the model can be used to optimize design of components.

In another preferred form of the present invention, there is provided a method for determining the risk of rupture of a blood vessel using an appropriate set of 2-D slice images obtained by scanning the blood vessel, the method comprising: generating a mesh model of the blood vessel using the set of 2-D slice images; conducting finite element stress analysis on the mesh model to calculate the level of stress on different locations on the mesh model; and determining the risk of rupture of the blood vessel based on the calculated levels of stress on different locations on the mesh model. In another preferred form of the present invention, there is provided an apparatus for determining the risk of rupture of a blood vessel using an appropriate set of 2-D slice images obtained by scanning the blood vessel, the apparatus comprising: apparatus for generating a mesh model of the blood vessel using the set of 2-D slice images; apparatus for conducting finite element stress analysis on the mesh model to calculate the level of stress on different locations on the mesh model; and apparatus for determining the risk of rupture of the blood vessel based on the calculated levels of stress on different locations on the mesh model.

A method of reconstructing a 3D model includes reconstructing a 3D voxel-based visual hull model using input images of an object captured by a multi view camera; converting the 3D voxel-based visual hull model into a mesh model; and generating a result of view-dependent rendering of a 3D model by performing the view-dependent texture mapping on the mesh model obtained through the conversion. Further, the reconstructing includes defining a 3D voxel space to be reconstructed; and excluding voxels not belonging to the object from the defined 3D voxel space.