Proceedings: GI 1996

Hierarchical Visibility Culling for Spline Models

Subodh Kumar, Dinesh Manocha

Proceedings of Graphics Interface '96: Toronto, Ontario, Canada, 22 - 24 May 1996, 142-150

DOI 10.20380/GI1996.17

  • BibTeX

     title = {Hierarchical Visibility Culling for Spline Models},
     author = {Subodh Kumar and Dinesh Manocha},
     booktitle = {Proceedings of the Graphics Interface 1996 Conference, May 22-24, 1996, Toronto, Ontario, Canada},
     year = {1996},
     month = {May},
     isbn = {0-9695338-5-3},
     publisher = {Canadian Human-Computer Communications Society},
     url = {},
     pages = {142--150}


We present hierarchical algorithms for visibility culling of spline models. This includes back-patch culling, a generalization of back-face culling for polygons to splines. These algorithms are extended to trimmed surfaces as well. We propose different spatial approximations for enclosing the normals of a spline surface and compare them for efficiency and effectiveness on different graphics systems. We extend the culling algorithms using hierarchical techniques to collection of surface patches and combine them with view-frustum culling to formulate a ONE (Object-Normal Exclusion)-tree for a given model. The algorithm traverses the ONE-tree at run time and culls away portions of the model not visible from the current viewpoint. These algorithms have been implemented and applied to a number of large models. In practice, we are able to speed-up the overall spline rendering algorithms by about 20-30% based on back-patch culling only and by more than 50% using ONE-trees.