48 results about "Visibility determination" patented technology

A method determines a set of mesh polygons or fragments of the mesh polygons visible from a view region having a plurality of view region vertices, the mesh polygons forming polygon meshes. The method includes determining at least one supporting polygon between the view region and the polygon meshes. The method further includes constructing at least one wedge from the at least one supporting polygon, the at least one wedge extending away from the view region beyond at least the polygon meshes. Further, the method includes determining one or more intersections of the wedges with the mesh polygons. Also, the method includes determining the set of the mesh polygons or fragments of the mesh polygons visible from the view region using the determined one or more intersections of the at least one wedge with the polygon meshes.

An intersection visibility determination device includes an ECU that determines visibility at an intersection. When a host vehicle approaches an intersection with a stop sign, the ECU calculates conflict points at which a trajectory vector of the host vehicle intersects with virtual trajectory vectors of intersecting objects, which are presumed to come from the right side and the left side of the intersection, respectively. The conflict points are calculated based on information on types and traveling positions of the intersecting objects. The ECU sets visibility determination areas at the intersection as viewed from the host vehicle based on the positions of the conflict points, the right-side and the left-side visibility target distances, and the current location of the host vehicle, and calculates, based on the visibility determination areas, visibility distances that are used as visibility parameters indicating whether the visibility at the intersection is good or poor.

In order to estimate changes in ambient visibility, this visibility estimation device is provided with: an image recognition unit (1) that detects landmarks by analyzing images; an information storage unit that records, as past detection history, image analysis results for the landmarks detected by the image recognition unit (1), and the detection positions when the image recognition unit (1) detects the landmarks; and a visibility determination unit (3) that estimates a change in visibility on the basis of comparisons between past detection positions recorded in the information storage unit (2) and the detection positions when the image recognition unit (1) redetects landmarks corresponding to the detection history recorded in the information storage unit (2).

The present invention provides a browser based mass three-dimensional point cloud data release method. The method comprises the following steps that S1. a bounding box of original three-dimensional point cloud data is calculated, and block division is carried out on the original three-dimensional point cloud data according to the bounding box and a regular grid division theory, so as to divide a plurality of block point cloud bounding boxes; S2. an octree is established for each block point cloud bounding box, and a description file is configured for each octree; S3. regular grid division is carried out on a point cloud octree, and a quadtree structure is established for the octree contained in each regular grid; and S4. a browser sends in real time a query request to a server, the server returns in real time an octree query result to the browser, the browser carries out visibility determination on the octree query result, and the visible octree is loaded, so as to complete dynamic loading and scheduling of mass three-dimensional point cloud data. According to the method disclosed by the present invention, web based release and visualization of mass large point cloud files are realized, and the problem that point cloud data is difficult to release is solved.

A method and apparatus for visibility determination and processing. The method includes receiving at least information associated with a plurality of objects, generating a first plurality of geometric primitives based on at least information associated with the plurality of objects, generating a first plurality of grids based on at least information associated with the first plurality of geometric primitives, and shading the first plurality of grids. The generating a first plurality of grids includes generating a second plurality of grids associated with the first plurality of geometric primitives, selecting a third plurality of grids from the second plurality of grids, and selecting the first plurality of grids from the third plurality of grids.

The invention relates to a 3D model rendering display method. The 3D model rendering display method comprises steps of determining whether a root node of each sub-block in an established 3D model is visible according to position information of a current viewpoint; partitioning the 3D model according to a three-dimensional coordinate direction into a plurality of sub-blocks, wherein each sub-block generates a corresponding adaptive tree LOD according to a hierarchy and data quantity information of each; according to the self-adaptive tree LOD, performing recursive traversal on a sub-tree from a visible root node and performing LOD visibility determination on all nodes under the root node; performing visibility determination and LOD accuracy test on all nodes under the root node layer by layer according to the hierarchy to obtain a corresponding hierarchy of a node which satisfies visibility and an LOD accuracy requirement; loading model data corresponding to the hierarchy satisfying the requirements; and rendering and displaying the 3D model. The invention also discloses a 3D model rendering display system, which solves defects of the LOD strategy in the prior art.

The embodiment of the present invention discloses a three-dimensional map rendering display method, including: calling the model file corresponding to the current scene model according to the map position information of the current viewpoint; wherein the data in the model file is cached in the form of an octree structure; The tree structure is combined with the viewing frustum of the current viewpoint, and the preset visibility judgment algorithm is used to judge the visibility of the level of detail LoD of all nodes in the current scene model, so as to mark the viewing range of the viewing frustum entering the current viewpoint in the model file Visible nodes and sub-nodes within; according to the marked visible nodes and sub-nodes, render and display the scene within the view range of the viewing frustum entering the current viewpoint. The invention also discloses a three-dimensional map rendering and display system. By adopting the invention, rendering efficiency is improved, network traffic is reduced, and large-scale point cloud data is displayed to users through Web three-dimensional technology.