The following publications are possibly variants of this publication:
- Hoops: 3D Curves as Conservative Occluders for Cell VisibilityPere Brunet, Isabel Navazo, Jarek Rossignac, Carlos Saona-Vázquez. cgf, 20(3):431-442, 2001.
- ShieldTester: Cell-to-Cell Visibility Test for Surface OccludersIsabel Navazo, Jarek Rossignac, J. Jou, R. Shariff. cgf, 22(3):291-302, 2003. [doi]