Most materials have some types of fine structures

which inevitably increase the complexity of realistic rendering. In this study

these complex structures are further categorized into three scales

namely

macroscale

mesoscale

and microscale. Each scale is modeled with different strategies. In particular

the macrostructures are modeled with traditional triangle meshes because these structures are large and visible under most circumstances. The mesostructures

which are tiny but still resolvable in the image

are represented by normal maps

whereas the smaller microstructures are directly depicted with a single roughness parameter because these structures have a significantly smaller size than the pixel width. For each scale

the normal distribution function (NDF) is obtained and fitted with a vMF distribution or mixtures of vMF distributions. Thereafter

the final NDF is approximated by convoluting each NDF. Furthermore

the paraboloid map and summed-area table are adopted to support real-time rendering of dynamic scenes

including time-varying lighting and deformed meshes. Experimental results reveal that the proposed approach can generate photorealistic surface reflections under varying viewpoints at a real-time frame rate. A real-time rendering method for rough surfaces with multi-scale properties is proposed in this study. Our method supports dynamic lighting and deformable objects.