surface_mesh_curvature.h

/********************************************************************
 * Copyright (C) 2020-2021 by Liangliang Nan <liangliang.nan@gmail.com>
 * Copyright (C) 2011-2020 the Polygon Mesh Processing Library developers.
 *
 * The code in this file is adapted from the PMP (Polygon Mesh Processing
 * Library) with modifications.
 *      https://github.com/pmp-library/pmp-library
 * The original code was distributed under a MIT-style license, see
 *      https://github.com/pmp-library/pmp-library/blob/master/LICENSE.txt
 ********************************************************************/
 
#ifndef EASY3D_ALGO_SURFACE_MESH_CURVATURE_H
#define EASY3D_ALGO_SURFACE_MESH_CURVATURE_H
 
#include <easy3d/core/surface_mesh.h>
 
namespace easy3d {

    class SurfaceMeshCurvature {
    public:
        explicit SurfaceMeshCurvature(SurfaceMesh *mesh);
        ~SurfaceMeshCurvature();

        void analyze(unsigned int post_smoothing_steps = 0);

        void analyze_tensor(unsigned int post_smoothing_steps = 0, bool two_ring_neighborhood = false);

        void compute_mean_curvature();

        void compute_gauss_curvature();

        void compute_max_abs_curvature();

        float mean_curvature(SurfaceMesh::Vertex v) const {
            return 0.5f * (min_curvature_[v] + max_curvature_[v]);
        }

        float gauss_curvature(SurfaceMesh::Vertex v) const {
            return min_curvature_[v] * max_curvature_[v];
        }

        float min_curvature(SurfaceMesh::Vertex v) const { return min_curvature_[v]; }

        float max_curvature(SurfaceMesh::Vertex v) const { return max_curvature_[v]; }

        float max_abs_curvature(SurfaceMesh::Vertex v) const {
            return std::max(fabs(min_curvature_[v]), fabs(max_curvature_[v]));
        }
 
    private:
        void smooth_curvatures(unsigned int iterations);
 
    private:
        SurfaceMesh *mesh_;
        SurfaceMesh::VertexProperty<float> min_curvature_;
        SurfaceMesh::VertexProperty<float> max_curvature_;
    };
 
} // namespace easy3d
 
 
#endif  // EASY3D_ALGO_SURFACE_MESH_CURVATURE_H