Shadow rendering for mesostructure surface based on height gradient map

The objects with mesostructure surfaces have difficulty in geometric modeling and have complex model structures, which result in low efficiency of shadow rendering algorithms. This paper presents a real-time rendering method for soft shadow based on height gradient map. To realize the real-time rendering, we propose a mesostructure description model, which has the mesostructure height field tied to the surfaces of low-resolution models by using texture coordinates to exhibit complex mesostructure models. We also introduce mesostructure height gradient map (MHGM) to create local apex sets of visible points. In the shadow rendering stage, the detailed shadow is generated by computing the occlusion of gradient-space local apex sets in real time. Our algorithm runs entirely in image space, and uses deferred shading and the graphics pipeline to show the self-shadowing effect of deformable objects in dynamic scenes.