Interactive High Quality Trimmed NURBS Visualization Using Appearance Preserving Tessellation

O. Deussen, C. Hansen, D. A. Keim, and D. Saupe (Editors)
In proceedings of TCVG Symposium on Visualization 2004, EUROGRAPHICS - IEEE, May 2004
Presented at TCVG Symposium on Visualization 2004
 

Abstract

Trimmed NURBS models are the standard representation used in CAD/CAM systems and accurate visualization of large trimmed NURBS models at interactive frame rates is of great interest for industry. To visualize the quality of a surface several techniques like isophotes, reflection lines, etc. are used. Most existing approaches transform the NURBS surfaces into a fine polygonal representation and build static levels of detail from this representation. This polygonal approximation together with its normals are adjusted in a semi-automatic procedure to achieve the desired visual fidelity during visualization. Since this approach allows only for a fixed maximum accuracy and does not support deformable models, another more recent approach is to keep the NURBS representation and generate view-dependent LODs on the fly up to the currently required preciseness.

However, so far this approach took only into account the geometric error of an approximation and thus neglected the various illumination artifacts introduced by the chosen (possibly view-dependent) triangulation. Although this problem can be solved by using normal maps, the resolution of the normal maps again limits the accuracy. Furthermore, the normal map generation requires a preprocessing step which prevents the support of deformable NURBS models. In this paper we present a novel automatic tessellation algorithm that considers the illumination artifacts and is well suited both for the generation of static and dynamic LOD schemes with guaranteed visual fidelity. Our new method is also capable of high quality visualization of further attributes like curvature, temperature, etc. on surfaces with little or no modification.

Keywords: appearance-preserving tessellation, trimmed NURBS real-time tessellation, Trimmed NURBS rendering

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Bibtex

@INPROCEEDINGS{guthe-2004-interactive,
      author = {Guthe, Michael and Bal{\'a}zs, {\'A}kos and Klein, Reinhard},
      editor = {Deussen, O. and Hansen, C. and Keim, D. A. and Saupe, D.},
       title = {Interactive High Quality Trimmed NURBS Visualization Using Appearance Preserving Tessellation},
   booktitle = {TCVG Symposium on Visualization 2004},
        year = {2004},
       month = may,
   publisher = {EUROGRAPHICS - IEEE},
    keywords = {appearance-preserving tessellation, trimmed NURBS real-time tessellation, Trimmed NURBS rendering},
    abstract = {Trimmed NURBS models are the standard representation used in CAD/CAM systems and accurate
                visualization of large trimmed NURBS models at interactive frame rates is of great interest for
                industry. To visualize the quality of a surface several techniques like isophotes, reflection lines,
                etc. are used. Most existing approaches transform the NURBS surfaces into a fine polygonal
                representation and build static levels of detail from this representation. This polygonal
                approximation together with its normals are adjusted in a semi-automatic procedure to achieve the
                desired visual fidelity during visualization. Since this approach allows only for a fixed maximum
                accuracy and does not support deformable models, another more recent approach is to keep the NURBS
                representation and generate view-dependent LODs on the fly up to the currently required preciseness.
                
                However, so far this approach took only into account the geometric error of an approximation and
                thus neglected the various illumination artifacts introduced by the chosen (possibly view-dependent)
                triangulation. Although this problem can be solved by using normal maps, the resolution of the
                normal maps again limits the accuracy. Furthermore, the normal map generation requires a
                preprocessing step which prevents the support of deformable NURBS models. In this paper we present a
                novel automatic tessellation algorithm that considers the illumination artifacts and is well suited
                both for the generation of static and dynamic LOD schemes with guaranteed visual fidelity. Our new
                method is also capable of high quality visualization of further attributes like curvature,
                temperature, etc. on
                surfaces with little or no modification.},
  conference = {TCVG Symposium on Visualization 2004}
}