Information
- Publication Type: Conference Paper
- Workgroup(s)/Project(s):
- Date: June 2007
- ISBN: 978-3-905673-52-4
- Publisher: Eurographics Association
- Organization: Eurographics
- Location: Grenoble, France
- Lecturer: Stefan Jeschke
- Editor: Jan Kautz and Sumanta Pattanaik
- Booktitle: Rendering Techniques 2007 (Proceedings Eurographics Symposium on Rendering)
- Pages: 10
- Conference date: 25. June 2007 – 27. June 2007
- Pages: 351 – 360
- Keywords: Display algorithms, Shading
Abstract
Shell mapping is a technique to represent three-dimensional surface details. This is achieved by extruding the triangles of an existing mesh along their normals, and mapping a 3D function (e.g., a 3D texture) into the resulting prisms. Unfortunately, such a mapping is nonlinear. Previous approaches perform a piece-wise linear approximation by subdividing the prisms into tetrahedrons. However, such an approximation often leads to severe artifacts. In this paper we present a correct (i.e., smooth) mapping that does not rely on a decomposition into tetrahedrons. We present an efficient GPU ray casting algorithm which provides correct parallax, self-occlusion, and silhouettes, at the cost of longer rendering times. The new formulation also allows modeling shells with smooth curvatures using Coons patches within the prisms. Tangent continuity between adjacent prisms is guaranteed, while the mapping itself remains local, i.e. every curved prism content is modeled at runtime in the GPU without the need for any precomputation. This allows instantly replacing animated triangular meshes with prism-based shells.Additional Files and Images
Additional images and videos
cube:
A shell-mapped cube
EnvMapI:
A shell-mapped and environment-mapped sphere
EnvMapII:
Closeup of a shell-mapped and environment-mapped sphere
Mapping:
Mapping between prisms in texture and world space
shadow:
Correct shadowing with shell mapping
teapots:
Shell mapped teapot with different textures
tiger:
Tiger model with a furry shell map
torus:
A shell-mapped torus
torusinside:
Inside view in a torus with different shell maps applied
TorusSmoothCurved:
Shell mapped torus. Left: smooth mapping. Right: curved mapping.
Additional files
Weblinks
No further information available.BibTeX
@inproceedings{JESCHKE-2007-ISC, title = "Interactive Smooth and Curved Shell Mapping", author = "Stefan Jeschke and Stephan Mantler and Michael Wimmer", year = "2007", abstract = "Shell mapping is a technique to represent three-dimensional surface details. This is achieved by extruding the triangles of an existing mesh along their normals, and mapping a 3D function (e.g., a 3D texture) into the resulting prisms. Unfortunately, such a mapping is nonlinear. Previous approaches perform a piece-wise linear approximation by subdividing the prisms into tetrahedrons. However, such an approximation often leads to severe artifacts. In this paper we present a correct (i.e., smooth) mapping that does not rely on a decomposition into tetrahedrons. We present an efficient GPU ray casting algorithm which provides correct parallax, self-occlusion, and silhouettes, at the cost of longer rendering times. The new formulation also allows modeling shells with smooth curvatures using Coons patches within the prisms. Tangent continuity between adjacent prisms is guaranteed, while the mapping itself remains local, i.e. every curved prism content is modeled at runtime in the GPU without the need for any precomputation. This allows instantly replacing animated triangular meshes with prism-based shells.", month = jun, isbn = "978-3-905673-52-4", publisher = "Eurographics Association", organization = "Eurographics", location = "Grenoble, France", editor = "Jan Kautz and Sumanta Pattanaik", booktitle = "Rendering Techniques 2007 (Proceedings Eurographics Symposium on Rendering)", pages = "10", pages = "351--360", keywords = "Display algorithms, Shading", URL = "https://www.cg.tuwien.ac.at/research/publications/2007/JESCHKE-2007-ISC/", }