100 results about "Height field" patented technology

A method, system, and computer program product are provided for visibility culling of terrain. A height field is perspective modulated. An occlusion height field is generated based on an orthographic height propagation of the perspective modulated height field. Graphics data is culled based on the generated occlusion height field. Texturing and blending operations can be used to accelerate the perspective modulation. A perspective modulation disk is used to modulate the first height field along radial slices from a viewpoint. Texture from a one-dimensional texture with distance values is mapped to the radial slices to obtain the perspective modulated height field. Generating an occlusion height field can also be carried out using texturing and blending and can be hardware-accelerated. According to a further feature, a shift disk or shift texture is used.

A system and method for shallow water simulation may provide a framework for solving General Shallow Wave Equations (GSWE) to efficiently simulate 3D fluid effects on arbitrary surfaces using a height field representation. The height field representation may include height columns constructed along surface normals, which may be dependent on a condition of boundary cells adjacent to fluid cells and/or artificial viscosity effects. The framework may provide implicit schemes for solving for the effects of external forces applied to the fluid, including gravity and surface tension, and explicit schemes for solving for advection effects. The system and method may be implemented on general-purpose CPU(s) and/or GPU(s) and may be capable of simulating a variety of fluid effects including: waves, rivulets and streams, drops, and capillary events. In some embodiments, the system and method may achieve real-time fluid control and fluid shape design through user-interaction (e.g., in a graphical painting application).

A system, methods, and computer-readable storage media for rendering height-field images that efficiently compute hard and soft shadows are disclosed. The system and methods may utilize a graphics representation comprising bounded 2D shapes with full 3D fill styles that affect shading, and an occlusion priority that determines visibility. The methods may include scan-coherent techniques for computing shadows from height-fields containing depth discontinuities while incrementally updating a convex hull of surface points. The methods may include a sweep-based algorithm for linear light source illumination of 2.5D graphical models across diagonal height-field cross-sections and/or a shear warp algorithm. Pre-computed (weighted) integrals corresponding to the light direction may be stored in tables according to a corresponding horizon angle and may be used in computing the lit intensity. The results may be free of aliasing artifacts. The methods may be implemented as program instructions, stored on computer-readable media, executable by a CPU and/or GPU.

An electronic file containing height field mapping data is output to a specialized printer and used to create one or more three dimensional molds. The molds, in turn, may be used to fabricate bas-relief tiles and similar three-dimensional objects from various materials. The process allows for rapid deployment of customized design elements in many construction applications and environments.

A realistic modeling and drawing method of shallow water wave comprises the following three aspects: using a shallow water equation based on the physical principle to simulate the water face height field; introducing the external force such as the wind force in the shallow water equation; simulating the water face with the ripples; drawing the reflection and refraction effects of the water face, realizing emulation of the optical features of the ripple surface, and improving realistic drawing in the shallow water scene; using the way combined with the shallow water equation to realize interaction of the ripple and the other object, and improving the interaction of the ripple. The invention utilizes the difference method to solve the shallow water equation introduced with the wind force, thereby ensuring simple and valid calculation and long time step stability, and realizing the real-time performance of the ripple simulation. When the realistic drawing is ensured, the calculation performance is improved.

The invention discloses a fluid-solid interaction simulation method based on video reconstruction and an SPH model. The fluid-solid interaction simulation method includes steps: 1), adopting a bright-dark recovery shape method to quickly reconstruct fluid surface geometric information in video, and acquiring a surface height field of each frame of input image; 2), combining the height fields with a shallow water equation, and calculating to acquire a speed field on the surface of fluid in a form of a minimizing energy equation; 3), using the surface geometric information as a boundary constraint condition to be discretized into a whole three-dimension body to acquire volume data; 4), guiding the volume data reconstructed in the video into an SPH simulation scene to serve as an initial condition of the simulation scene, and interacting with other virtual environment objects in the scene. By the fluid-solid interaction simulation method, high-accuracy data reconstruction can be realized, fluid surface details can be retained, bidirectional interaction simulation is performed on the basis of reconstructed data and a physical simulation model, fluid animation effect closer to real condition is acquired, algorithm complexity is low, and the method has high creativity compared with related algorithms.

A “mesostructure renderer” uses pre-computed multi-dimensional “generalized displacement maps” (GDM) to provide real-time rendering of general non-height-field mesostructures on both open and closed surfaces of arbitrary geometry. In general, the GDM represents the distance to solid mesostructure along any ray cast from any point within a volumetric sample. Given the pre-computed GDM, the mesostructure renderer then computes mesostructure visibility jointly in object space and texture space, thereby enabling both control of texture distortion and efficient computation of texture coordinates and shadowing. Further, in one embodiment, the mesostructure renderer uses the GDM to render mesostructures with either local or global illumination as a per-pixel process using conventional computer graphics hardware to accelerate the real-time rendering of the mesostructures. Further acceleration of mesostructure rendering is achieved in another embodiment by automatically reducing the number of triangles in the rendering pipeline according to a user-specified threshold for acceptable texture distortion.

The invention discloses a three-dimensional geographic information platform and a topographic data processing method thereof. The platform comprises a network system layer, a data layer, a supporting layer, an application layer and a presentation layer; the application layer comprises a computer network and a hardware platform, and the safety of the computer network is guaranteed; the data layer is a natural resource and geographic space information data resource center; the supporting layer is a basic platform for operation and management of a space database and a model database; the application layer is a supporting layer-based industry application module integration platform; the presentation layer comprises WFS, WMS, WCS and a browse layer. A three-dimensional model used in the invention is formed by third-party professional modeling software, and also, the software can be used for forming simple three-dimensional model scenes, namely, a large area of simple three-dimensional scenes can be fast generated by adding a height field and a layer height field into attribute information according to polygon files in data line pictures.

The invention discloses a tsunami motion forecasting method based on multi-hierarchy interaction, which comprises the following steps: 1) generating hierarchical grids according to the position of an actual tsunami source, establishing corresponding relation between the grids and spherical coordinates, and establishing an interaction mechanism of the hierarchical grids; 2) carrying out sector and square combined dispersion on a tsunami motion equation, setting initial conditions and boundary conditions according to actual conditions, and solving a wave equation to compute flux change of tsunami motion; and 3) setting an initial sea level height field according to the height of a sea level, establishing an interaction mechanism of particles and the grids in the process of tsunami motion, establishing updating and iterating rules of the particles, and then, forecasting the height of tsunami through interaction of the particles and the grids. The method can quickly and vividly forecast the tsunami propagation phenomenon and solves the problems that the existing simulation method only pays attention to numerical simulation, the simulation result is not visual, the computing efficiency is too slow, and the like. The method has certain practical value in the fields of disaster prevention, tsunami early warning, virtual simulation etc.

Methods and systems of representation and manipulation of surfaces with perceptual geometric features, using a computer graphics rendering system, include executing algorithmic instructions to compute a plurality of vertices, edges and surfaces in a mesh for the purpose of defining representations of surfaces on grids. Normals and distances are determined for triangular surfaces to be considered. Additionally, height fields of a function are defined. A set of feature curves and a set of feature points are derived, based on the defined function. Infinitesimal movements along the representations of the surfaces are determined, along with derivations of properties of representations of continuous surfaces. Additional determinations of perceptual geometric features include determinations such as zero crossings, parabolic curves, flecnodes, ruffles, gutterpoints, conical points and biflecnodes in a given mesh. After these determinations are made, visual representation are rendered which captures perceptually important features for smoothly varying shapes.

The application provides a navigation grid automatic-generation method and a navigation grid automatic-generation device. The method comprises the following steps: converting an input model into a voxel model which consists of multiple set voxels, and establishing a height field data structure which corresponds to the voxel model; restrictively selecting voxels which doe not meet parameter restrictions from the height field data structure according to parameter restriction set by player roles, and marking non-walkable identifiers; selecting a walkable region from the voxel model according to the voxels marked with the non-walkable identifiers in the height field data structure; dividing the walkable region into multiple subregions, and simplifying the outline of each subregion; triangularizing the subregions with simplified outlines, establishing connection, and forming a navigation grid, thereby realizing automatic generation of the navigation grid.

A “mesostructure renderer” uses pre-computed multi-dimensional “generalized displacement maps” (GDM) to provide real-time rendering of general non-height-field mesostructures on both open and closed surfaces of arbitrary geometry. In general, the GDM represents the distance to solid mesostructure along any ray cast from any point within a volumetric sample. Given the pre-computed GDM, the mesostructure renderer then computes mesostructure visibility jointly in object space and texture space, thereby enabling both control of texture distortion and efficient computation of texture coordinates and shadowing. Further, in one embodiment, the mesostructure renderer uses the GDM to render mesostructures with either local or global illumination as a per-pixel process using conventional computer graphics hardware to accelerate the real-time rendering of the mesostructures. Further acceleration of mesostructure rendering is achieved in another embodiment by automatically reducing the number of triangles in the rendering pipeline according to a user-specified threshold for acceptable texture distortion.

The present invention discloses a face relief geometric modeling method, and belongs to the field of relief modeling. The problems are solved that current portrait relief modeling is low in efficiencyand poor in automation. The method comprises the following steps of: performing face key feature point location for an input single face image, and obtaining face image feature points; based on a BFMparameter face model, constructing an initial 3D face; based on a Bi-Laplacian constrained point displacement method to perform shape optimization of the initial 3D face, and generating a 3D face after shape optimization; performing height field optimization of the 3D face after shape optimization based on a relation of the face image illumination intensity and the 3D face geometric normal, and generating a 3D face after height optimization; and performing linear compression of the 3D face after the height field optimization, generating an original 3D face relief, performing geometric detailoptimization of the original face relief through a Bi-Laplacian grid deformation method based on key point constraint, and generating a face relief with rich geometric details.

The invention discloses a method for extracting and automatically drawing characteristic points of groove and ridge lines, and the method comprises the following steps: enabling grid point meteorological data with 0-degree, 45-degree and 90-degree gradient directions after discretization to serve as the candidate characteristic points of the ridge line according to the direction of the groove ridge line in a temperature/height field; enabling grid point meteorological data with -180-degree, -135-degree and -90-degree gradient directions after discretization to serve as the candidate characteristic points of the groove line; carrying out the error correction and filtering of the characteristic points of the ridge line and the characteristic points of the groove line, and obtaining the final characteristic points of the ridge line and the final characteristic points of the groove line; carrying out beam search according to the final characteristic points of the ridge line and the final characteristic points of the groove line, forming a folded line, enabling the ridge and groove lines, which do not meet conditions, to be eliminated, and obtaining the selected ridge and groove lines; carrying out the smooth axis processing of the selected ridge and groove lines, and obtaining the final smooth ridge and groove lines. The method achieves the automatic detection of the groove and ridge lines, facilitates the forecasting of weather disasters, and reduces the economic loss and persons.

The invention discloses a raster image vectorizing method based on a contour line. The raster image vectorizing method based on the contour line includes: generating an intensity image corresponding to a raster image firstly, and then establishing an image height field by using the intensity image after being smoothed; extracting equal altitude points in the image height field, and confirming colors of the equal altitude points; establishing parameter curve math expression of the contour line based on the equal altitude points, and conforming the color of an arbitrary point on the contour line. A parameter curve set with color information is vectorization expression of the raster image. When a reestablishment raster image is expressed in vectorization mode, zooming and discretization operations are performed on a vectorized parameter curve according to the size of the raster image to be established, the position and the color of each pixel occupied by the vectorized parameter curve in the image to be established are confirmed, a coloring pixel is used as initial data, and a color diffusion method is used to reestablish the raster image which is expressed in vectorization mode. The raster image vectorizing method based on the contour line can perform multiple scale vectorization processing on various raster images, can use relative parameters to control the data volume of a vector diagram, and can reestablish the raster image multiple in resolution through vector expression.

A data structure for cloth animation and an apparatus and method of rendering 3D graphics data using the data structure. The data structure for cloth animation comprises a vertical granulation field, a horizontal granulation field, a height field, a width field, and a physical characteristics node which defines values for physical characteristics, a shift position of the cloth due to forces acting on the cloth, and due to a collision of the cloth with an object. The 3D graphics data rendering apparatus comprises an analyzer for outputting a scene graph, a calculator for calculating physical quantities for the cloth animation, and a converter for converting the scene graph comprising the calculated physical quantities into a 2D image and outputting the 2D image.

The present invention is directed to a method and system and computer program for decomposing a triangle mesh representing the surface of a digital object model, reconstructed from 3D scanning data, into a small number of height-field patches (partitions) (in the order of the number of the original scans) with reasonable angular variations with the direction from which the viewer is looking at the digital object and with boundaries as regular as possible, in order to map a texture. The present method uses the original scan information (even when scans are divided into two or more connected meshes), but without selecting a single scan per mesh area.

The invention discloses a water body modeling method for a shallow water equation model with optimized parameters. According to the method, first, a three-dimensional dynamic coordinate system is constructed, and the shallow water equation model with optimized parameters is derived; when the model is solved, a reverse path tracking method and a method of characteristics are combined to solve an advective item in an equation, a vector projection method and a Fourier transformation method are combined to solve the effect of external acting force on a water body, and therefore a velocity field and a height field are updated; next, boundary check is performed, a boundary truncation method is adopted to process mesh points beyond a boundary; and last, the height field is drawn, and a next time period is processed cyclically. Compared with a traditional shallow water equation, when the contact surface between the water body and a solid is excessively steep, a water body model can be constructed more vividly and accurately, and the velocity of average 24.9 frame/second can be reached in the water body modeling simulation process; compared with a traditional method, the velocity is increased by 29.016%, and real-time simulation can be realized basically.

The invention relates to a method for inverting geologic body geometrical morphology by combining data fusion with different heights. The method is to carry out joint processing on the air and groundmeasured data, based on the analysis principle that different height data correspond to the same field source at the same time and is used for inverting the field source, and the application range ofthe field data of different heights in the euler deconvolution method is expanded. The different height field data fusion is combined with the euler deconvolution method, which can solve the scattering problem brought by the single observation surface data calculation, so that the basic contour of the abnormal source can be rapidly and effectively drawn. The method is especially suitable for large-area grid heavy magnetic data calculation and large-depth analysis and interpretation of different height data fusion combined with inversion geologic body geometrical shapes. The thought that a single observation surface data calculation is adopted in the prior art is broken through, the geometrical morphology of the geologic body can be more clearly and accurately divided, and the depth resolution capability of the geologic body is improved.

The invention provides a data driving inshore surge animation synthesis method and a system and belongs to the image processing and computer vision field. The method comprises steps that a monocular video of water surface videos is reconstructed, the height field data of the monocular video is acquired, opening operation reconstruction and closing operation reconstruction for the water surface videos are carried out, surge masks are acquired, the surge masks are processed through a morphological refinement algorithm, and the surge framework information is acquired; according to the surge masks and the surge framework information, a rapid surge height change model is constructed, and a frame sequence graph is acquired according to the rapid surge height change model and the height field data; a target shape of surge inputted by a user is acquired, an initial shape of the surge in the frame sequence graph is changed into the target shape, and the target shape generates animation. Through the method, reusability of the reconstruction data is improved, and the surge information and the control mode are made to be more simple and visual.

The invention discloses a computing method of a video fluid height. The computing method comprises the following steps: firstly, initializing motion vectors of a fluid according to fluid motion features; utilizing LBM to compute the height of fluid particles in accordance with a result of the motion vectors; denoising and smoothing the height; utilizing LBM to perform recurrence on the height of continuous multiframes to obtain a height computing result with physical motion features of the fluid according to the continuity of the fluid motion; utilizing a linear interpolation of fluid particle distribution functions to obtain a height result of uniform changes of continuous motion fluids; and finally correcting the fluid height by using intermediate frames. The computing method provided by the invention is simple, convenient and fast. By using the computing method, a fluid height field of continuous changes can be obtained, and a real-time height result is produced. The computing method can be suitable for constructing virtual scenes of natural landscapes and has an application value; and with the adoption of the computing method, the real-time interaction of the fluid motion in the virtual scenes can be realized effectively, and the poor real-time capability in reconstruction based on a vision method is overcome.

An air bearing slider which includes a raised bearing surface or surfaces contoured to limit off nodal pressurization. The air bearing surfaces are located proximate to nodal regions of a height field or profile between the slider and disc surface to limit off-nodal pressurization. The air bearing slider includes a narrow raised bearing surface profile proximate to the trailing edge of the slider body and an expanded intermediate profile along an intermediate portion to provide lift and roll stability proximate to an intermediate nodal region of the slider body to limit off nodal pressurization.