[2011-11-27 19:38:53 -0500] Nicholas Bishop: > 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
Hi, There was a gsoc project last year [1] about the implementation of mixed integer quadrangulationsa [2] into blender. I don't know where this project lies now, but I believe this code uses a curvature estimator to generate a direction field on the surface. Thanks for this work, -- Vincent [1] http://code.google.com/p/google-summer-of-code-2010-blender/ [2] http://www.graphics.rwth-aachen.de/uploads/media/bommes_zimmer_2009_siggraph_01.pdf _______________________________________________ Bf-committers mailing list [email protected] http://lists.blender.org/mailman/listinfo/bf-committers
