View frustum projection clipping method for large-scale terrain rendering

Abstract

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.

Description

technical field [0001] The invention relates to a viewing frustum projection clipping method applied in large-scale terrain rendering, belonging to the fields of virtual reality and computer simulation. Background technique [0002] Frustum clipping is the basis of many problems in computer graphics. The purpose of frustum clipping is to extract the required information from geometric data. It is also used in algorithms such as Boolean operations, hidden lines and hidden surfaces, and shadow generation. Very useful tool. The most typical application of frustum clipping is to intercept a partial view from a large frame. In the 3D visualization of terrain, because the terrain generally involves a very wide range, the terrain model has a large amount of data, often containing millions of triangles, such as transforming and cutting them one by one. is a big burden. If the parts invisible to the user can be removed in advance during real-time terrain rendering, the speed of re...

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Problems solved by technology

[0014] The purpose of the present invention is to solve the problem that a large number of terrain blocks that should not be displayed are rendered and increase the rendering pressure, and a frustum projection clipping method applied in large-scale terrain rendering is proposed

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