Nicholas, For your information, the GSoC 2008 Freestyle branch contains C++ code for computing principal curvatures and directions. The code seems to be based on published schemes (Meyer et al. 2002 and Cohen-Steiner et al. 2003) as indicated by citations in comments. These references are cited by Rusinkiewicz's paper you have cited. The curvature code is in source/blender/freestyle/intern/winged_edge/Curvature.cpp and an application is in FEdgeXDetector::computeCurvatures() in source/blender/freestyle/intern/view_map/FEdgeXDetector.cpp.
Regards, -- KAJIYAMA, Tamito <[email protected]> -----Original Message----- From: Nicholas Bishop Sent: Monday, November 28, 2011 12:38 AM To: bf-blender developers Subject: [Bf-committers] Mesh curvature estimation Hi all, A few times I've run into algorithms that require principal curvatures [1] as inputs. My cursory examination of the Blender source (basically just grepping for "curvature") didn't turn up any code for this, so I ported the (GPLv2) curvature code from the trimesh2 lib [2] to Blender. That code is based on the paper "Estimating Curvatures and Their Derivatives on Triangle Meshes" [3]. Dunno if this is useful to anyone else, but I've pushed a Blender branch [4] containing the curvature calculation (in blenlib/intern/curvature.c), as well as a test modifier that displays the curvature vectors. Screenshot with Suzanne: http://www.pasteall.org/pic/show.php?id=21557 Notes: The original code was in C++; I converted it to C and switched the math stuff over to blenlib and the types to MVert/MFace/etc. The per-vertex output is the two principal curvatures and two direction vectors. I haven't updated the code to handle quads yet, it'll assert() if it encounters a non-triangle face. I've only just gotten this working, so there are definitely bugs in it yet. :) Thanks, -Nicholas [1] http://en.wikipedia.org/wiki/Principal_curvature [2] http://gfx.cs.princeton.edu/proj/trimesh2/ [3] http://gfx.cs.princeton.edu/pubs/_2004_ECA/ [4] https://gitorious.org/~nicholasbishop/blenderprojects/nicholasbishop-blender/commits/tri-curvature _______________________________________________ Bf-committers mailing list [email protected] http://lists.blender.org/mailman/listinfo/bf-committers
