MOTIVATION: Extract features (bumps, ridges, valleys, inflections) from arbitrary surfaces at multiple scales. Applied to line-based rendering, illustrative shading, 3D shape editing, etc.
INSPIRATION: Guennebaud et al work on Algebraic Point Set Surfaces. Koenderink et al work on solid shape invariants.
 c103-f103_3-a48-representative_image-v1 Screen-Space Curvature for Production-Quality Rendering and Compositing.
Nicolas Mellado, Pascal Barla, Gaël Guennebaud, Patrick Reuter, Gregory Duquesne.
Siggraph Talk program, 2013.
Archive –  paper  – videoplugin
pertinentArmadillo Growing Least Squares for the Continuous Analysis of Manifolds in Scale-Space.
Nicolas Mellado, Pascal Barla, Gaël Guennebaud, Patrick Reuter, Christophe Schlick. 
Computer Graphics Forum, Proceedings of Symposium on Geometry Processing 2012.
Archive  –  paper  –  library
teaser-isis2-all Surface Relief Analysis for Illustrative Shading.
Ammann Lucas, Pascal Barla, Xavier Granier, Gael Guennebaud, Patrick Reuter.
Computer Graphics  Forum, Wiley, 2012, 31 (4)
Archive  –  paper  –  video
horsecol-4 Implicit Brushes for Stylized Line-based Rendering,
Romain Vergne, David Vanderhaeghe, Jiazhou Chen, Pascal Barla, Xavier Granier, Christophe Schlick,
Computer Graphics Forum 30, 2 (proceedings of Eurographics 2011)