For our project we would like to render a realistic picture of soap. Soap is an interesting subject for several reasons. First of all, it's an everyday object that is familiar to everyone. At the same time, it can be a centerpiece of whimsical and artistic images. Upon first glance, soap seems simple, but a deeper inspection reveals complex surface properties, detailed imperfections, and interesting light scattering behavior. Soap is a versatile medium which can range in color and texture from smooth and translucent to opaque, milky colored, and waxy. Finally, a bar of soap easily fits in your pocket. We aim to render a well lit image of bars of soap on a glossy white surface, hoping to exhibit interesting subsurface scattering and global illumination effects.
For inspiration, we found several interesting images of soap that we would like to reproduce.
We foresee several major aspects to this project:
- Subsurface scattering to model light through the bulk soap material.
- Surface geometry to reproduce the waxy, scratchy, imperfect look of hand made soap. We aim to investigate bump mapping and perhaps modeling the surface micro-geometry.
- Indirect illumination and color bleeding from light reflected and transmitted through soap.
We plan to start by figuring out the basic surface geometry of a bar of soap. We will start with a simple geometric cube and perturb surface normals using bump mapping or possibly displacement mapping techniques. We will also start investigating the BSSRDF subsurface scattering model for thick surfaces.
Pat Hanrahan and Wolfgang Kreuger: "Reflection from Layered Surfaces due to Subsurface Scattering". Computer Graphics (Proceedings of SIGGRAPH 1993), July 1993.
Henrik Wann Jensen, Stephen R. Marschner, Marc Levoy and Pat Hanrahan: "A Practical Model for Subsurface Light Transport". Proceedings of SIGGRAPH 2001.
S. Merillou, J. M. Dischler, D. Ghazanfarpour: "Surface scratches: measuring, modeling and rendering".