Crack-free rendering of dynamically tesselated B-rep models

• Published in: Computer graphics forum 2014-05, Vol.33 (2), p.263-272
• Main Authors: Claux, Frédéric, Barthe, Loïc, Vanderhaeghe, David, Jessel, Jean-Pierre, Paulin, Mathias
• Format: Article
• Language: English
• Subjects: Analysis; Categories and Subject Descriptors (according to ACM CCS); Computer graphics; Computer Science; Cracks; Dynamics; Flaw detection; Graphics; I.3.3 [Computer Graphics]: Picture/Image Generation-Display algorithms; I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling-Boundary representations; Image detection; Image processing systems; Mathematical models; Navigation; Rendering; Run time (computers); Studies
• ISSN: 0167-7055; 1467-8659
• DOI: 10.1111/cgf.12308

We propose a versatile pipeline to render B‐Rep models interactively, precisely and without rendering‐related artifacts such as cracks. Our rendering method is based on dynamic surface evaluation using both tesselation and ray‐casting, and direct GPU surface trimming. An initial rendering of the scene is performed using dynamic tesselation. The algorithm we propose reliably detects then fills up cracks in the rendered image. Crack detection works in image space, using depth information, while crack‐filling is either achieved in image space using a simple classification process, or performed in object space through selective ray‐casting. The crack filling method can be dynamically changed at runtime. Our image space crack filling approach has a limited runtime cost and enables high quality, real‐time navigation. Our higher quality, object space approach results in a rendering of similar quality than full‐scene ray‐casting, but is 2 to 6 times faster, can be used during navigation and provides accurate, reliable rendering. Integration of our work with existing tesselation‐based rendering engines is straightforward.