A wave optics based fiber scattering model
| Autor: | Mengqi (Mandy) Xia, Eric Michielssen, Bruce Walter, Steve Marschner, David Bindel |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Diffraction Scattering Forward scatter business.industry Plane wave Physics::Optics 020207 software engineering 02 engineering and technology Physical optics Computer Graphics and Computer-Aided Design Ray Cross section (physics) Optics 0202 electrical engineering electronic engineering information engineering Fiber business |
| Zdroj: | ACM Transactions on Graphics. 39:1-16 |
| ISSN: | 1557-7368 0730-0301 |
| DOI: | 10.1145/3414685.3417841 |
| Popis: | Existing fiber scattering models in rendering are all based on tracing rays through fiber geometry, but for small fibers diffraction and interference are non-negligible, so relying on ray optics can result in appearance errors. This paper presents the first wave optics based fiber scattering model, introducing an azimuthal scattering function that comes from a full wave simulation. Solving Maxwell's equations for a straight fiber of constant cross section illuminated by a plane wave reduces to solving for a 3D electromagnetic field in a 2D domain, and our fiber scattering simulator solves this 2.5D problem efficiently using the boundary element method (BEM). From the resulting fields we compute extinction, absorption, and far-field scattering distributions, which we use to simulate shadowing and scattering by fibers in a path tracer. We validate our path tracer against the wave simulation and the simulation against a measurement of diffraction from a single textile fiber. Our results show that our approach can reproduce a wide range of fibers with different sizes, cross sections, and material properties, including textile fibers, animal fur, and human hair. The renderings include color effects, softening of sharp features, and strong forward scattering that are not predicted by traditional ray-based models, though the two approaches produce similar appearance for complex fiber assemblies under many conditions. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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