Real-time soft shadow realization method based on image screen space

Abstract

The invention discloses a real-time soft shadow realization method based on an image screen space. The method comprises the following steps that: A, all objects in a visible range of a virtual camera in a scene are traversed; B, a light source space is built, a vein used for storing the depth in a screen space is created, and a shadow map is generated; C, a world position coordinate is converted into a lamp light space through projection conversion, and a depth map of new positions of pixels is obtained; D, the depth of the new positions of the pixels is compared with the shadow map to judge which pixels are positioned in the shadow, so that a shadow mask is obtained; E, the shadow mask is subjected to Gaussian blur processing; and F, the shadow mark subjected to the Gaussian blur processing is overlaid with the scene color, and a soft shadow effect is achieved. The real-time soft shadow realization method has the advantages that the traditional PCF (Percentage Closer Filtering) based on sampling veins is improved; the problem of the phenomenon of saw tooth generation on the boundary of a scene model is effectively solved; a better soft shadow effect is achieved; in addition, the effect of realizing the soft shadow effect on complicated scenes is also very good; and the drawing efficiency is high.

Description

technical field [0001] The invention relates to the technical field of soft shadows, in particular to a method for realizing real-time soft shadows based on image screen space. Background technique [0002] As a very important function of the light and shadow effect in the game engine, the shadow plays a vital role in the virtual game. With this effect, the three-dimensionality and layers of the image will be richer, and the real feeling of the scene will also be improved. Shadows can be divided into soft and hard shadows. Hard shadow algorithms are relatively simple, while real-time soft shadows are more realistic than hard shadows. However, the realization of dynamic soft shadows is a difficult point in computer graphics research. The implementation process of traditional real-time soft shadows is as follows: First, a depth map (shadow map) containing scene depth information is generated from the light source as the viewpoint, and then the scene is rendered into a screen t...

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Problems solved by technology

The implementation process of traditional real-time soft shadows is as follows: First, a depth map (shadow map) containing scene depth information is generated from the light source as the viewpoint, and then the scene is rendered into a screen texture buffer from the viewer's viewpoint, and then the sampled texture is processed. Multi-sample average (percentage closer filtering, PCF), the soft shadow quality produced by this method is directly related to the number of samples, if you want to get a softer soft shadow effect, you need a lot of texture sampling, which is inefficient

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