Interactive Fracture System Tutorial. Tutorials. Your community resource for 3ds MAXScript or SketchUp Rubyscript. Ego Lounge - Tutorials, Resources, and Help for the Digital Content Creator. ICT Graphics Lab. (a) High-Res face geometry obtained by embossing a specular normal map (estimated from polarized gradient illumination) onto a structured light 3D scan. All information was acquired in 13 photographs from two digital still cameras. (b) Real-time rendering of low-res face geometry with hybrid normal mapping for diffuse and specular reflectance. (c) Offline GI&SSS rendering using the high-resolution geometry and recovered diffuse and specular intensity maps. We estimate surface normal maps of an object from either its diffuse or specular reflectance using four spherical gradient illumination patterns. In contrast to traditional photometric stereo, the spherical patterns allow normals to be estimated simultaneously from any number of viewpoints.