vpMbtPolygon.cpp

/*
 * ViSP, open source Visual Servoing Platform software.
 * Copyright (C) 2005 - 2025 by Inria. All rights reserved.
 *
 * This software is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * See the file LICENSE.txt at the root directory of this source
 * distribution for additional information about the GNU GPL.
 *
 * For using ViSP with software that can not be combined with the GNU
 * GPL, please contact Inria about acquiring a ViSP Professional
 * Edition License.
 *
 * See https://visp.inria.fr for more information.
 *
 * This software was developed at:
 * Inria Rennes - Bretagne Atlantique
 * Campus Universitaire de Beaulieu
 * 35042 Rennes Cedex
 * France
 *
 * If you have questions regarding the use of this file, please contact
 * Inria at visp@inria.fr
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 *
 * Description:
 * Make the complete tracking of an object by using its CAD model
 *
 * Authors:
 * Romain Tallonneau
 * Aurelien Yol
 */
 
#include <limits.h>
 
#include <visp3/core/vpConfig.h>
 
#include <visp3/core/vpPolygon.h>
#include <visp3/mbt/vpMbtPolygon.h>
 
BEGIN_VISP_NAMESPACE
vpMbtPolygon::vpMbtPolygon()
  : index(-1), isvisible(false), isappearing(false), useLod(false), minLineLengthThresh(50.0),
  minPolygonAreaThresh(2500.0), name(""), hasOrientation(true)
{ }
 
vpMbtPolygon::vpMbtPolygon(const vpMbtPolygon &mbtp)
  : vpPolygon3D(mbtp), index(mbtp.index), isvisible(mbtp.isvisible), isappearing(mbtp.isappearing), useLod(mbtp.useLod),
  minLineLengthThresh(mbtp.minLineLengthThresh), minPolygonAreaThresh(mbtp.minPolygonAreaThresh), name(mbtp.name),
  hasOrientation(mbtp.hasOrientation)
{
  //*this = mbtp; // Should not be called by copy constructor to avoid multiple assignments.
}
 
vpMbtPolygon &vpMbtPolygon::operator=(const vpMbtPolygon &mbtp)
{
  vpPolygon3D::operator=(mbtp);
  index = mbtp.index;
  isvisible = mbtp.isvisible;
  isappearing = mbtp.isappearing;
  useLod = mbtp.useLod;
  minLineLengthThresh = mbtp.minLineLengthThresh;
  minPolygonAreaThresh = mbtp.minPolygonAreaThresh;
  name = mbtp.name;
  hasOrientation = mbtp.hasOrientation;
 
  return (*this);
}

bool vpMbtPolygon::isVisible(const vpHomogeneousMatrix &cMo, double alpha, const bool &modulo,
                             const vpCameraParameters &cam, unsigned int width, unsigned int height)
{
  //   std::cout << "Computing angle from MBT Face (cMo, alpha)" << std::endl;
 
  changeFrame(cMo);
 
  if (nbpt <= 2) {
    // Level of detail (LOD)
    if (useLod) {
      vpCameraParameters c = cam;
      if (clippingFlag > 3) { // Contains at least one FOV constraint
        c.computeFov(width, height);
      }
      computePolygonClipped(c);
      std::vector<vpImagePoint> roiImagePoints;
      getRoiClipped(c, roiImagePoints);
 
      if (roiImagePoints.size() == 2) {
        double x1 = roiImagePoints[0].get_u();
        double y1 = roiImagePoints[0].get_v();
        double x2 = roiImagePoints[1].get_u();
        double y2 = roiImagePoints[1].get_v();
        double length = std::sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
        //          std::cout << "Index=" << index << " ; Line length=" <<
        //          length << " ; clippingFlag=" << clippingFlag << std::endl;
        //        vpTRACE("index=%d length=%f minLineLengthThresh=%f", index,
        //        length, minLineLengthThresh);
 
        if (length < minLineLengthThresh) {
          isvisible = false;
          isappearing = false;
          return false;
        }
      }
    }
 
    /* a line is always visible when LOD is not used */
    isvisible = true;
    isappearing = false;
    return true;
  }
 
  // If the polygon has no orientation, the angle check visibility is always
  // valid. Feature mainly used for cylinders.
  if (!hasOrientation) {
    isvisible = true;
    isappearing = false;
    return true;
  }
 
  // Check visibility from normal
  // Newell's Method for calculating the normal of an arbitrary 3D polygon
  // https://www.opengl.org/wiki/Calculating_a_Surface_Normal
  vpColVector faceNormal(3);
  vpColVector currentVertex, nextVertex;
  for (unsigned int i = 0; i < nbpt; i++) {
    currentVertex = p[i].cP;
    nextVertex = p[(i + 1) % nbpt].cP;
 
    faceNormal[0] += (currentVertex[1] - nextVertex[1]) * (currentVertex[2] + nextVertex[2]);
    faceNormal[1] += (currentVertex[2] - nextVertex[2]) * (currentVertex[0] + nextVertex[0]);
    faceNormal[2] += (currentVertex[0] - nextVertex[0]) * (currentVertex[1] + nextVertex[1]);
  }
  faceNormal.normalize();
 
  vpColVector e4(3);
  vpPoint pt;
  for (unsigned int i = 0; i < nbpt; i += 1) {
    pt.set_X(pt.get_X() + p[i].get_X());
    pt.set_Y(pt.get_Y() + p[i].get_Y());
    pt.set_Z(pt.get_Z() + p[i].get_Z());
  }
  e4[0] = -pt.get_X() / static_cast<double>(nbpt);
  e4[1] = -pt.get_Y() / static_cast<double>(nbpt);
  e4[2] = -pt.get_Z() / static_cast<double>(nbpt);
  e4.normalize();
 
  double angle = acos(vpColVector::dotProd(e4, faceNormal));
 
  //  vpCTRACE << angle << "/" << vpMath::deg(angle) << "/" <<
  //  vpMath::deg(alpha) << std::endl;
 
  if (angle < alpha || (modulo && (M_PI - angle) < alpha)) {
    isvisible = true;
    isappearing = false;
 
    if (useLod) {
      vpCameraParameters c = cam;
      if (clippingFlag > 3) { // Contains at least one FOV constraint
        c.computeFov(width, height);
      }
      computePolygonClipped(c);
      std::vector<vpImagePoint> roiImagePoints;
      getRoiClipped(c, roiImagePoints);
 
      vpPolygon roiPolygon(roiImagePoints);
      double area = roiPolygon.getArea();
      //      std::cout << "After normal test ; Index=" << index << " ; area="
      //      << area << " ; clippingFlag="
      //          << clippingFlag << std::endl;
      if (area < minPolygonAreaThresh) {
        isappearing = false;
        isvisible = false;
        return false;
      }
    }
 
    return true;
  }
 
  if (angle < alpha + vpMath::rad(1)) {
    isappearing = true;
  }
  else if (modulo && (M_PI - angle) < alpha + vpMath::rad(1)) {
    isappearing = true;
  }
  else {
    isappearing = false;
  }
 
  isvisible = false;
  return false;
}
 
//###################################
//      Static functions
//###################################

void vpMbtPolygon::setLod(bool use_lod) { this->useLod = use_lod; }
END_VISP_NAMESPACE