/* ========================================================================= * * * * OpenMesh * * Copyright (c) 2001-2015, RWTH-Aachen University * * Department of Computer Graphics and Multimedia * * All rights reserved. * * www.openmesh.org * * * *---------------------------------------------------------------------------* * This file is part of OpenMesh. * *---------------------------------------------------------------------------* * * * Redistribution and use in source and binary forms, with or without * * modification, are permitted provided that the following conditions * * are met: * * * * 1. Redistributions of source code must retain the above copyright notice, * * this list of conditions and the following disclaimer. * * * * 2. Redistributions in binary form must reproduce the above copyright * * notice, this list of conditions and the following disclaimer in the * * documentation and/or other materials provided with the distribution. * * * * 3. Neither the name of the copyright holder nor the names of its * * contributors may be used to endorse or promote products derived from * * this software without specific prior written permission. * * * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A * * PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER * * OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * * * ========================================================================= */ /** \file ModNormalFlippingT.hh */ //============================================================================= // // CLASS ModNormalFlipping // //============================================================================= #ifndef OPENMESH_DECIMATER_MODNORMALFLIPPING_HH #define OPENMESH_DECIMATER_MODNORMALFLIPPING_HH //== INCLUDES ================================================================= #include //== NAMESPACES =============================================================== namespace OpenMesh { // BEGIN_NS_OPENMESH namespace Decimater { // BEGIN_NS_DECIMATER //== CLASS DEFINITION ========================================================= /** Decimating module to avoid flipping of faces. * * This module can be used only as a binary module. The criterion * of allowing/disallowing the collapse is the angular deviation between * the face normal of the original faces and normals of the faces after the * collapse. The collapse will pass the test, if the deviation is below * a given threshold. */ template class ModNormalFlippingT : public ModBaseT< MeshT > { public: DECIMATING_MODULE( ModNormalFlippingT, MeshT, NormalFlipping ); public: /// Constructor explicit ModNormalFlippingT( MeshT &_mesh) : Base(_mesh, true) { set_max_normal_deviation( 90.0f ); const bool mesh_has_normals = _mesh.has_face_normals(); _mesh.request_face_normals(); if (!mesh_has_normals) { omerr() << "Mesh has no face normals. Compute them automatically." << std::endl; _mesh.update_face_normals(); } } ~ModNormalFlippingT() { Base::mesh().release_face_normals(); } public: /** Compute collapse priority due to angular deviation of face normals * before and after a collapse. * * -# Compute for each adjacent face of \c _ci.v0 the face * normal if the collpase would be executed. * * -# Prevent the collapse, if the cosine of the angle between the * original and the new normal is below a given threshold. * * \param _ci The collapse description * \return LEGAL_COLLAPSE or ILLEGAL_COLLAPSE * * \see set_max_normal_deviation() */ float collapse_priority(const CollapseInfo& _ci) override { // simulate collapse Base::mesh().set_point(_ci.v0, _ci.p1); // check for flipping normals typename Mesh::ConstVertexFaceIter vf_it(Base::mesh(), _ci.v0); typename Mesh::FaceHandle fh; typename Mesh::Scalar c(1.0); for (; vf_it.is_valid(); ++vf_it) { fh = *vf_it; if (fh != _ci.fl && fh != _ci.fr) { typename Mesh::Normal n1 = Base::mesh().normal(fh); typename Mesh::Normal n2 = Base::mesh().calc_face_normal(fh); c = dot(n1, n2); if (c < min_cos_) break; } } // undo simulation changes Base::mesh().set_point(_ci.v0, _ci.p0); return float( (c < min_cos_) ? Base::ILLEGAL_COLLAPSE : Base::LEGAL_COLLAPSE ); } /// set the percentage of maximum normal deviation void set_error_tolerance_factor(double _factor) override { if (_factor >= 0.0 && _factor <= 1.0) { // the smaller the factor, the smaller max_deviation_ gets // thus creating a stricter constraint // division by error_tolerance_factor_ is for normalization double max_normal_deviation_value = (max_deviation_ * 180.0/M_PI) * _factor / this->error_tolerance_factor_; set_max_normal_deviation(max_normal_deviation_value); this->error_tolerance_factor_ = _factor; } } public: /// get normal deviation double max_normal_deviation() const { return max_deviation_ / M_PI * 180.0; } /** Set normal deviation * * Set the maximum angular deviation of the orignal normal and the new * normal in degrees. */ void set_max_normal_deviation(double _d) { max_deviation_ = _d / 180.0 * M_PI; min_cos_ = cos(max_deviation_); } private: // hide this method void set_binary(bool _b) {} private: // maximum normal deviation double max_deviation_, min_cos_; }; //============================================================================= } // END_NS_DECIMATER } // END_NS_OPENMESH //============================================================================= #endif // OPENMESH_DECIMATER_MODNORMALFLIPPING_HH defined //=============================================================================