Real-time soft shadow rendering method for point light sources

Abstract

The invention discloses a method based on cubic texture shadow mapping in order to overcome the shortcomings that shadow edges are ubiquitously too hard in shadow mapping at present, and real soft shadows cannot be achieved. The shadow edges are softened in a special optimization mode, jags are eliminated, and satisfactory soft shadow effects of point light sources are achieved. The method includes the steps: judging whether the point light sources in a scene are visual point light sources or not by calculating whether a visual angle cone and a point light source illumination sphere are intersected or not to obtain a visual point light source list; judging whether each visual point light source is a potential projector or not by calculating whether the point light source illumination sphere and a spherical bounding box in the scene are intersected or not to obtain a potential projector list; rendering the potential projector into a cubic texture for each visual point light source; and performing scene illumination rendering for each visual point light source and optimizing shadow edge quality by a percentage approach filtering algorithm during shadow processing.

Description

technical field [0001] The invention relates to the field of graphics, in particular to a method for real-time shadow rendering for a point light source model. Background technique [0002] Shadows are of great significance to human observation and cognition of the three-dimensional world. Shadows can help people judge the position, size and geometric information of occluded objects, and can also help people understand the geometric shape of occluded objects. Shadows give information about the position of light sources in the scene and highlight the spatial relationship between objects, so shadows can greatly enhance the realism of the scene and are an indispensable part of rendering technology. Shadow rendering is used in computer graphics images, Digital multimedia and other fields have broad application prospects. [0003] As a point light source model widely used in indoor scenes, because its projection is omnidirectional, many technologies use Shadow Volume to achieve...

AI Technical Summary

Problems solved by technology

They have the inherent disadvantages of shadow bodies: the shadow edges are too hard to achieve the effect of real soft shadows; the triangle fill rate is too high, which affects rendering performance

There are also some technologies that use ordinary shadow maps (Shadow Maps) to render projections in a certain direction, but cannot achieve the omnidirectional projection characteristics of the point light source model.

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