57 results about "Terrain rendering" patented technology

A multi-resolution texture mapping system suitable for large scale terrain rendering using commodity graphics processing units (GPU). The GPU vertex and fragment shaders are used to implement the clip-mapping functionality. The terrain texture is represented by a combination of a mip-map and a multi-level clip-map having independent origins and off-set values. The independent clip-map levels may be independently updated. The offset values allow the origins to be associated with a reference point in a scene to be rendered. The desired clip-map level to be used to render a particular fragment may be determined using the base 2 logarithm of the maximum screen-space derivative of the source texture required by the terrain geometry to be drawn. If the desired clip-map level is non-integer and lies between two clip-map levels, appropriate texel data is created by interpolating between the bounding clip-map levels. This interpolation allows a multi-resolution texture mapping to be displayed.

A novel and non-trivial system and methods for displaying partial images and non-overlapping images acquired by vision systems representing scene is disclosed. A system is disclosed for displaying partial images and shared, non-overlapping images on a display comprises a forward-looking imaging device system, an image system, a terrain rendering processor, and an indicating system. The terrain rendering processor determines, based on visibility data, which part of an image of one system will be displayed. A method is disclosed for displaying a partial image on a display unit. A terrain rendering processor determines acceptable and unacceptable visibility data based on contrast data of first image data, and based on such determination, presents image data corresponding to unacceptable data to the indicating system for presentation on a display unit. A second method is disclosed for displaying two images on a display unit of an aircraft. A terrain rendering processor determines acceptable and unacceptable visibility data based on contrast data of first image data, and based on such determination, presents image data corresponding to both acceptable and unacceptable data to the indicating system for presentation on a display unit.

The invention discloses a three-dimensional vector real-time dynamic stacking technique based on multiple LOD (Level of Detail) transparent textures. The three-dimensional vector real-time dynamic stacking technique comprises the following steps of: firstly, drawing various vector layers on the transparent textures of corresponding plotting scales respectively in an internal memory through data pre-processing, automatically carrying out block cutting on the vector layers, then saving the vector layers in a disk as an LOD pyramid data storage structure, and establishing a mapping relation with a same-level terrain and an image data block; and secondly, in a real-time terrain rendering and roaming stage, loading the transparent textures of vectors of the corresponding layers through dynamic selection, stacking the vector layers into the same level of image data block according to an established Alpha passage, and realizing the real-time stacking of the vector layers in the three-dimensional terrain based on an internal memory multi-passage texture blending technology. According to seamless visualization of high-resolution vector map data and a digital elevation model, the effect of the high-resolution vector map data and the digital elevation model in spatial information expression and analysis can be enhanced. According to the technique, the real time stacking of multilayer vector data in the rendering and roaming stage of a large-scale three-dimensional terrain scene is realized, and the dynamic interactive screening of the vector layers is supported.

The invention provides a fractal multi-resolution simplified method used for large-scale terrain rendering. The method comprises the following steps: (1) determining a terrain grid rendering region in a scene, firstly carrying out equidistant grid resampling on DEM (digital elevation model) data of coarser grids to form a terrain quadtree node; (2) projecting a view point to an XOZ plane, creating a terrain multi-resolution frame, and setting a plurality of different resolution levels from 1 to n on the terrain by adopting the multi-resolution LOD (level of detail) technology according to the view point; and (3) determining the level of the terrain according to the distances between the view point and different regions of a model, extracting characteristic parameters from an original DEM data set, adopting a DEM-based fractal random midpoint displacement interpolation to generate a continuous real terrain, and realizing reconstruction of a large-scale terrain. The terrain realized by adopting the method in the invention has good space continuity, cracks between different levels in a common multi-resolution model can be avoided, and smooth transition of different resolution models can be realized.

The invention discloses an accelerated terrain rendering method based on a graphics processor. Not only a problem of a T-shaped crack occurring in a level of detail (LOD) rendering process can be solved effectively, but also operation resource of a central processing unit (CPU) is saved, and a processing performance of the CPU is improved due to the fact that calculation is based on the graphics processor. By means of the method, a large-scale terrain can be rendered on a computer only supporting Direct three-dimensional (3D) 9 in high quality and high performance mode, and the method can be widely applied to 3D games and virtual reality application programs. The accelerated terrain rendering method includes the following steps: dividing an original terrain image into a plurality of terrain blocks with same area; using LOD terrain rendering arithmetic, and building different LOD-level vertex buffer and index buffer; using a quad-tree to organize the whole original terrain, each leaf node corresponds to a terrain block; rendering the terrain; using a graphics processing unit (GPU) to conduct Vertex Shader programming, obtaining height value of a terrain block vertex from a height map by using a vertex texture sampling function; and modifying the height value of a vertex.

A method of rendering a terrain stored in a massive database the said terrain rendering being displayed for an observer by a display device comprising at least one graphics card comprising a cache memory, comprises at least: a step of generating several regular grids of different resolution level terrain patches so as to represent the terrain data of the massive database; a step of extracting terrain data from the massive database for several resolution levels, the extracted terrain data forming an extraction pyramid, composed of an extraction window for each level of detail, placed in cache memory. Each window comprises an active zone intended to be displayed, and a preloading zone which makes it possible to anticipate the transfers of data; a step of selecting the patches of the extraction pyramid which contribute to the image; and a step of plotting the rendering on the basis of the selected patches.

The invention discloses a construction method for a 3D dynamic visual simulation platform for multimode navigation. The method comprises the following specific steps: a human-computer interaction platform is constructed on the basis of MFC (Microsoft foundation classes) in VC++ and OSG 3D rendering engine environment, a 3D digital earth scene and natural environment are rendered with an OSGEarth terrain rendering toolkit, and a 3D model of an airplane and a virtual simulation scene model of an airport are established with 3D modeling software and loaded to the 3D digital earth scene. Key point data of a flight line is acquired, and interpolation way point data is obtained through processing and used for driving flight of the airplane. During flight of the airplane, a rover is used for tracking and observing the airplane, flight data of the airplane is updated by an event processor, and the flight data is displayed in real time. The construction method has the advantages of easiness in secondary development, real timeliness and high efficiency, and increases the real-time efficiency of data display.

The invention discloses a screen-based three-dimensional linear symbol rendering method, which utilizes a shader language to realize high-efficiency high-quality rendering of linear map symbols in a three-dimensional map. The method includes the steps of establishing a mapping relation between vector line segments and a terrain unit, and encoding vector nodes and indexes, thereby forming node texture and index texture; in a fragment shader, searching and reestablishing vector line segments associated with a current fragment; performing grouping and ranking on vector line segment indexes, solving texture coordinates of line segment nodes in the node texture, and reading node attributes from the node texture; and selecting corresponding rendering functions according to symbol types of the associated line segments, and arranging a calculation sequence according to priority. Through direct calculation of screen fragments, the screen-based three-dimensional linear symbol rendering method provided by the invention can realize lamination rendering of linear symbols in a terrain rendering process. In addition, precise spatial position relation calculation and flexible fragment operation meet rendering of different types of linear symbols, and ensure efficiency of real-time rendering.

In some embodiments, a method for high-performance terrain rendering may include one or more of the following steps: (a) obtaining elevation data, (b) determining slope of a terrain surface, (c) selecting a shading model to apply to the terrain surface based upon the slope of the terrain surface, (d) determining if a vehicle's heading has changed, and (e) aligning the shading model index based upon current heading.

The invention provides a local refreshing method of large-scale terrain rendering in a three-dimensional scene. The local refreshing method comprises steps that step1: a local terrain region required to be loaded is preprocessed; step2: various levels of terrain tiles superposed with the local terrain region are acquired; step3: the data refreshing of the local terrain region is realized. When the local terrain data is loaded in the three-dimensional scene, not all of terrain data are required to be reloaded, and only the local terrain blocks required to be loaded are updated, and therefore data scheduling time is reduced, and the refreshing speed of the loaded terrain data is guaranteed.

The present invention relates to a method for rendering a multi-resolution terrain using GPU tessellation.

A method for rendering a terrain using GPU tessellation according to an embodiment of the present invention may include: generating a quad patch to which an inner tessellation factor and an edge tessellation factor are allocated by using a quadtree including a parent node and child nodes; generating a base mesh b using the quad patch; and restoring a terrain by applying a displacement map to the base mesh.

A method for rendering a real-time conformal view of terrestrial body's terrain being traversed by a mobile platform includes storing digital terrain elevation data (DTED) tiles for at least a portion of the terrain of a terrestrial body into an external removable mass data storage device (ERMDSD). The ERMDSD is connectable to an onboard computer system (OCS) comprising embedded mobile platform components that include at least one processing card, at least random access memory (RAM) device and at least one graphics card. The method additionally includes executing a real-time rendering assist application (RTRAA) stored in the processing card to dynamically repackage the DTED tiles into DTED chunks being representative of an area of the terrestrial body to be traversed (ATBT) by the mobile platform. The method further includes executing the RTRAA to create a base mesh of root diamonds representative of the ATBT and tessellate the root diamonds to create a plurality of leaf diamonds. Further yet the method includes utilizing the graphics card only to render the leaf diamonds, thereby generating a real-time conformal view of the ATBT.

The invention discloses a terrain rendering method which comprises the following steps: acquiring terrain image data, and performing quadtree segmentation on the terrain image data to obtain a plurality of terrain tiles; Creating a texture array of each terrain tile according to the layer-by-layer number, the image width and the image height of the terrain image data; Storing texture images and texture coordinates of all layers of the terrain image data in the current terrain tile through the texture array of each terrain tile; And performing terrain rendering according to the texture image and the texture coordinates in the texture array of each terrain tile. Wherein the texture array is not limited by the layer-by-layer number of the image, so that the limitation of a computer display card on the number of texture units can be avoided, layer-by-layer rendering is not needed in the rendering process, and the rendering efficiency is improved. The terrain rendering device and equipmentand the readable storage medium disclosed by the invention also have the above technical effects.

The invention provides a view frustum projection clipping method for large-scale terrain rendering and belongs to the fields of virtual reality and computer simulation. According to the method, firstly, determining the equivalent shape such as a sector or a circle of view frustum projection in accordance with the spatial position of a view frustum; then, calculating related geometric information of the equivalent shape of the view frustum projection; finally, performing point clipping according to a bottom right point of the square formed by the horizontal projection of a terrain block bounding box and the view frustum projection equivalent area to determine whether the terrain block is within the scope of the view frustum. The view frustum projection clipping method for large-scale terrain rendering performs simplification and equivalent conversion on the horizontal projection of the view frustum according to the position of the view frustum to directly reflect the shape of the view frustum projection, uses point clipping to determine the result of the clipping to effectively simplify the calculation process, and solves the problem that a large number of terrain rendering blocks which should not be displayed are rendered and increase rendering pressure.

A system and method for terrain rendering using a limited memory footprint is presented. A system and method to perform vertical ray terrain rendering by using a terrain data subset for image point value calculations. Terrain data is segmented into terrain data subsets whereby the terrain data subsets are processed in parallel. A bottom view ray intersects the terrain data to provide a memory footprint starting point. In addition, environmental visibility settings provide a memory footprint ending point. The memory footprint starting point, the memory footprint ending point, and vertical ray adjacent data points define a terrain data subset that corresponds to a particular vertical ray. The terrain data subset includes height and color information which are used for vertical ray coherence terrain rendering.

A system and method for terrain rendering using a limited memory footprint is presented. A vertical ray intersects a terrain data map at an angle which includes a minor step size. Weighting factors are assigned to triangular data sampling values and quadrilateral data sampling values based upon a vertical ray's minor step size. As a vertical ray's minor step size increases, a triangular data sampling's weighting factor increases and a quadrilateral data sampling's weighting factor decreases. Weighted triangular data sampling values and weighted quadrilateral data sampling values are combined to generate a vertical ray image point value.

The invention relates to a rendering method, in particular to a method for rendering terrain through offline optimization, belonging to the technical field of computer graphics. The method comprises a step of: (4) filtering useless grids in a map. The method for rendering the terrain through the offline optimization is beneficial to further optimizing a map resource through the arts and reducing the size of the map resource; simultaneously, more collision detection about the terrain is reduced, and the running efficiency of a CPU (Central Processing Unit) is improved, therefore, the fixity of grid information is utilized to the maximum extent, and visible storage is performed in an offline manner; therefore, drawing of the grid is reduced to the maximum extent, and a purpose of increasing the number of frames is achieved.

The invention discloses a virtual terrain rendering method for dynamically processing and caching resources based on a GPU. The method comprises the following steps: constructing a terrain grid according to a spatial quadtree algorithm; gradually subdividing the terrain and cutting the view cone according to a viewpoint position, and creating GPU end caches for different terrain resources according to the resources positioned by the logic coordinates to realize different shader programs; starting different rendering processes for different resources, and storing the processed resources in a cache opened up by a GPU; writing a shader for terrain rendering to create a drawing instruction for the remaining nodes after terrain cutting, and submitting Draw Call to a GPU to complete drawing. According to the method, the computing power of the GPU is fully utilized, rendering work is submitted to the GPU, processing work of rendering resources is submitted to the GPU to be completed, and therefore resource processing work is greatly accelerated. Meanwhile, a whole set of GPU resource caching and access algorithm is realized, the access performance of resources is accelerated, the rendering performance is further improved, and real-time rendering and flexible editing of super-large-scale virtual terrains become possible.

The invention discloses a visual synthesis method and system based on a low-power-consumption hardware platform. The method comprises determining a terrain tile level through a preset terrain tile grading model and based on the ground clearance of an airplane, thereby calculating terrain tile data according to the level. The method is capable of reducing the number of tiles participating in subsequent calculation and final rendering, reducing performance consumption and increasing frame rate; in addition, the problem of flicker at the tile boundary due to insufficient vertex depth value precision is solved through a method of converting world coordinates into relative coordinates; and a specific satellite image data storage format is adopted, so that the loading speed can be increased whenthe satellite image data is loaded. The system can smoothly operate the synthetic vision system under the low-power hardware platform, can flexibly configure the terrain rendering precision in the synthetic vision and the number of three-dimensional objects in the scene according to different application scenes and requirements, and adapts to the rendering performance of different low-power hardware platforms.

Embodiments of the invention provide a terrain rendering method and apparatus. The method comprises the following steps: acquiring the altitude of an unmanned aerial vehicle at each reference positionin a designated area and the simulated ground height of the unmanned aerial vehicle, wherein the simulated ground height refers to the vertical height between the unmanned aerial vehicle and the ground; determining the terrain height of each reference position by using the altitude of each reference position and the simulated ground height; and subjecting the terrain height between every two adjacent reference positions to interpolation processing so as to obtain terrain rendering results. The terrain rendering method and apparatus provided by the embodiments of the invention can detect the terrain of flat-bottomed land and accurately measure the terrain of some mountainous areas, and are wider in application scope.