A run time visibility algorithm based on major occluder for complicated scene with high density is presented. First

some classic visibility algorithm such as Beam Tree

Potential Visible Set(PVS) technique and other ideas based on shading objects are summarized in this paper. Then an improved algorithm based on real time application is presented. By creating an occluding tree dynamically through primary shading objects predefined in the scene user designed

the new algorithm can eliminate all objects and scenes in the shading area of the shading tree. The algorithm performs very high efficiency when the scene user designed is organized according to Binary Space Partitioning(BSP) tree and rendered from front to back. The algorithm apply simplified shading proxy different form shading objects to primary shading objects

and present an efficient and practical simplified method for shading objects with box type. The new improved algorithm has been applied to RTG 3D Real time Graphics Toolkits and the ability of obviously increasing rendering speed for complicated scene has been verified by many practical instances in developing procedure.