3D Graphics Engine Application For Real-time Soft Shadows

With the continuous progress of information technology, people have higherrequirements for the excellent visual effects. Games, film and video production uses alot of computer graphics technology for processing. Generated as the shadow of one ofthe key technologies in simulation technology, faced with increasing challenges.Shadow plays an important role in the three-dimensional space, can help determine theposition, and the record is not available to meet the role of information between objects.Shadowing techniques cited by the study for many years, divided into hard shadow andsoft shadow effects, hard shadow is defined as the point light source or parallel light isthe point in space there may be two possibilities, in the shadows and not and then theshadow. Hard shadow look, stiff, rigid, unlike reality in the shadows. Soft shadows inthe case of non-point source, the points in space may receive some light, namely thepresence of penumbral soft shadows more than the hard shadow close to the real shadow,but the calculation of soft shadow volume, real-time. In this paper, two types ofalgorithms based on image space and object space-based research, analyze theadvantages and disadvantages. Shadow map rendering speed, based on this algorithmwill not lead to the complexity of the algorithm increased as scene complexity increases;but such algorithms tend to have inherited the common problem of the graphic spacealgorithm-aliasing, soft shadow quality. Another algorithm is based on the objectspace, most of the advantages derived from the shadow volume algorithm, thesealgorithms is the physical accuracy of the shadow, the shadow of high quality; but suchmethods are heavily dependent on the geometric information of objects in the scene,once in the complex scene, the complexity of the algorithm will become very high.