Real-time soft shadow algorithms can render convincing soft shadows on complex and dynamic scenes with a single shadow map. In this paper

we propose a hybrid rendering method

which extracts edges for area light in object space and determines the edge pixel’s direction in image space. Then

we use the Hierarchical Edge Map to compute the visibility. The results show

the cost of silhouette extracting is reduced and the rendering performance is improved. Furthermore

the accuracy of the contour and the shadow quality are both enhanced.