A projection mapping method of a video in a three-dimensional scene based on a screen space

The invention discloses a projection mapping method of a video in a three-dimensional scene based on a screen space, comprising the steps of preprocessing to obtain internal and external parameters ofa projection source and a depth map; Drawing three-dimensional scene from current viewpoint, obtaining diffuse reflection map and depth map of current viewpoint; The texture is drawn from the projection source, and each pixel of the projection picture is converted to the screen space of the viewpoint for projection calculation. The problem of occlusion penetration caused by the loss of depth value in traditional projection texture mapping is solved, the method not only enhances the rendering effect significantly, but also reduces the number of rendering batches and enhances the rendering efficiency. The invention has the advantages of clear algorithm, robust result and high operation efficiency, and is very suitable for application in real-time rendering system. The method can be well combined with a large-scale three-dimensional video monitoring system.