source: orxonox.OLD/trunk/src/lib/graphics/importer/static_model_data.cc @ 10145

/*
   orxonox - the future of 3D-vertical-scrollers

   Copyright (C) 2004 orx

   This program 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, or (at your option)
   any later version.

   ### File Specific:
   main-programmer: Benjamin Grauer
   co-programmer: ...

   2005-07-06: (Patrick) added new function buildTriangleList()
*/

#define DEBUG_SPECIAL_MODULE DEBUG_MODULE_IMPORTER

#include "static_model_data.h"

#include "debug.h"
#include <stdarg.h>
#include <algorithm>



////////////////////
/// SUB-Elements ///
////////////////////
/**
 * @brief creates a new ModelFaceElement
 */
StaticModelData::FaceElement::FaceElement()
{
  this->vertexNumber = -1;
  this->normalNumber = -1;
  this->texCoordNumber = -1;
}


/**
 * @brief creates a new ModelFace
 */
StaticModelData::Face::Face()
{
  this->_material = NULL;
}

/**
 * @brief Creates a new ModelGroup
 */
StaticModelData::Group::Group()
{
  PRINTF(4)("Adding new Group\n");
  this->name = "";
  this->faceMode = -1;
  this->listNumber = 0;
  this->indices = NULL;
}

/**
 * @brief deletes a ModelGroup
 */
StaticModelData::Group::~Group()
{
  PRINTF(5)("Cleaning up group\n");
  // deleting the glList
  if (this->listNumber != 0)
    glDeleteLists(this->listNumber, 1);
}

/**
 * @brief cleans up a ModelGroup
 *
 * actually does the same as the delete Operator, but does not delete the predecessing group
 */
void StaticModelData::Group::cleanup()
{
  PRINTF(5)("Cleaning up group\n");
  this->_faces.clear();
}




/////////////
/// MODEL ///
/////////////
ObjectListDefinition(StaticModelData);

/**
 * @brief Creates a 3D-Model.
 *
 * assigns it a Name and a Type
 */
StaticModelData::StaticModelData(const std::string& modelName)
{
  this->registerObject(this, StaticModelData::_objectList);
  PRINTF(4)("new 3D-Model is being created\n");
  this->setName(modelName);

  this->finalized = false;

  // setting the start group;
  this->_modelGroups.push_back(Group());
  this->faceCount = 0;

  this->scaleFactor = 1.0f;
}

/**
 * @brief deletes an Model.
 *
 * Looks if any from model allocated space is still in use, and if so deleted it.
 */
StaticModelData::~StaticModelData()
{
  PRINTF(4)("Deleting Model %s\n", this->getCName());
  this->cleanup();
}

/**
 * @brief Finalizes an Object. This can be done outside of the Class.
 */
void StaticModelData::finalize()
{
  // this creates the display List.
  this->importToDisplayList();
  this->buildTriangleList();

  this->finalized = true;
}

/**
 * @brief rebuild the Model from the Information we got.
 */
void StaticModelData::rebuild()
{
  PRINTF(3)("Rebuilding Model '%s'\n", this->getCName());
  this->finalize();
}

//////////
// DRAW //
//////////
/**
 * @brief Draws the Models of all Groups.
 *
 * It does this by just calling the Lists that must have been created earlier.
 */
void StaticModelData::draw () const
{
  PRINTF(4)("drawing the 3D-Models\n");

  for(unsigned int i = 0; i < _modelGroups.size(); ++i )
  {
    PRINTF(5)("Drawing model %s\n", _modelGroups[i].name.c_str());
    glCallList (_modelGroups[i].listNumber);
  }
}


/**
 * @brief Draws the Model number groupNumber
 * @param groupNumber The number of the group that will be displayed.
 *
 * It does this by just calling the List that must have been created earlier.
 */
void StaticModelData::draw (unsigned int groupNumber) const
{
  if (unlikely(groupNumber >= _modelGroups.size()))
  {
    PRINTF(2)("You requested model number %i, but this File only contains of %i Models.\n", groupNumber-1, _modelGroups.size());
    return;
  }
  else
  {
    PRINTF(4)("Drawing model number %i named %s\n", groupNumber, _modelGroups[groupNumber].name.c_str());
    glCallList (_modelGroups[groupNumber].listNumber);
  }
}


/**
 * @brief Draws the Model with a specific groupName
 * @param groupName The name of the group that will be displayed.
 *
 * It does this by just calling the List that must have been created earlier.
 */
void StaticModelData::draw (const std::string& groupName) const
{
  PRINTF(4)("drawing the requested 3D-Models if found.\n");
  std::vector<Group>::const_iterator it = std::find(_modelGroups.begin(), _modelGroups.end(), groupName);

  if (it != _modelGroups.end())
  {
    PRINTF(4)("Drawing model %s\n", (*it).name.c_str());
    glCallList ((*it).listNumber);
  }
  else
  {
    PRINTF(2)("Model Named %s in %s not Found.\n", groupName.c_str(), this->getCName());
  }
}

//////////
// INIT //
//////////

/**
 * @brief finalizes an Model.
 *
 * This funcion is needed, to delete all the Lists, and arrays that are no more
 * needed because they are already imported into openGL.
 * This will be applied at the end of the importing Process.
*/
bool StaticModelData::cleanup()
{
  PRINTF(4)("cleaning up the 3D-Model to save Memory.\n");
  for (unsigned int i = 0; i < _modelGroups.size(); ++i)
    _modelGroups[i].cleanup();
  return true;
}

//////////
// MESH //
//////////
/**
 * @brief adds a new Material to the Material List
 * @param material the Material to add
 * @returns the added material
 *
 * this also tells this Model, that all the Materials are handled externally
 * with this option set the Materials will not be deleted with the Model.
 */
Material* StaticModelData::addMaterial(const Material& material)
{
  this->materialList.push_back(material);
  return &materialList.back();
}

/**
 * @brief adds a new Material to the Material List
 * @param materialName the name of the Material to add
 * @returns the added material
 */
Material* StaticModelData::addMaterial(const std::string& materialName)
{
  // adding material to the List of materials
  this->materialList.push_back(Material(materialName));
  return &materialList.back();
}

/**
 * @brief finds a Material by its name and returns it
 * @param materialName the Name of the material to search for.
 * @returns the Material if found, NULL otherwise
 */
Material* StaticModelData::findMaterialByName(const std::string& materialName)
{
  std::list<Material>::iterator it = std::find(materialList.begin(), materialList.end(), materialName);
  if (it != materialList.end())
    return &(*it);
  else
    return NULL;
}

/**
 * @brief parses a group String
 * @param groupString the new Group to create
 *
 * This function initializes a new Group.
 * With it you should be able to create Models with more than one SubModel inside
 */
bool StaticModelData::addGroup(const std::string& groupString)
{
  PRINTF(5)("Read Group: %s.\n", groupString.c_str());
  if (!_modelGroups.empty() && !_modelGroups.back()._faces.empty())
    _modelGroups.push_back(Group());

  if (groupString == "default")
    _modelGroups.back().name = groupString;
  // setting the group name if not default.
  return true;
}

/**
 * @brief parses a vertex-String
 * @param vertexString The String that will be parsed.
 *
 *  If a vertex line is found this function will inject it into the vertex-Array
 */
bool StaticModelData::addVertex (const std::string& vertexString)
{
  float subbuffer1;
  float subbuffer2;
  float subbuffer3;
  sscanf (vertexString.c_str(), "%f %f %f", &subbuffer1, &subbuffer2, &subbuffer3);
  this->vertices.push_back(subbuffer1*scaleFactor);
  this->vertices.push_back(subbuffer2*scaleFactor);
  this->vertices.push_back(subbuffer3*scaleFactor);
  return true;
}

/**
 * @brief parses a vertex-String
 * @param x the X-coordinate of the Vertex to add.
 * @param y the Y-coordinate of the Vertex to add.
 * @param z the Z-coordinate of the Vertex to add.
 */
bool StaticModelData::addVertex(float x, float y, float z)
{
  PRINTF(5)("reading in a vertex: %f %f %f\n", x, y, z);
  this->vertices.push_back(x*scaleFactor);
  this->vertices.push_back(y*scaleFactor);
  this->vertices.push_back(z*scaleFactor);
  return true;
}

/**
 * @brief parses a vertexNormal-String
 * @param normalString The String that will be parsed.
 *
 * If a vertexNormal line is found this function will inject it into the vertexNormal-Array
 */
bool StaticModelData::addVertexNormal (const std::string& normalString)
{
  float subbuffer1;
  float subbuffer2;
  float subbuffer3;
  sscanf (normalString.c_str(), "%f %f %f", &subbuffer1, &subbuffer2, &subbuffer3);
  this->normals.push_back(subbuffer1);
  this->normals.push_back(subbuffer2);
  this->normals.push_back(subbuffer3);
  return true;
}

/**
 * @brief adds a VertexNormal.
 * @param x The x coordinate of the Normal.
 * @param y The y coordinate of the Normal.
 * @param z The z coordinate of the Normal.
 *
 * If a vertexNormal line is found this function will inject it into the vertexNormal-Array
 */
bool StaticModelData::addVertexNormal(float x, float y, float z)
{
  PRINTF(5)("found vertex-Normal %f, %f, %f\n", x, y, z);
  this->normals.push_back(x);
  this->normals.push_back(y);
  this->normals.push_back(z);
  return true;
}

/**
 * @brief parses a vertexTextureCoordinate-String
 * @param vTextureString The String that will be parsed.
 *
 * If a vertexTextureCoordinate line is found,
 * this function will inject it into the vertexTexture-Array
 *
 * !! WARNING THIS IS DIFFERNT FROM addVervexTexture(float, float); because it changes the second entry to 1-v !!
 */
bool StaticModelData::addVertexTexture (const std::string& vTextureString)
{
  float subbuffer1;
  float subbuffer2;
  sscanf (vTextureString.c_str(), "%f %f", &subbuffer1, &subbuffer2);
  this->vTexture.push_back(subbuffer1);
  this->vTexture.push_back(1 - subbuffer2);
  return true;
}

/**
 * @brief adds a Texture Coordinate
 * @param u The u coordinate of the TextureCoordinate.
 * @param v The y coordinate of the TextureCoordinate.
 *
 * If a TextureCoordinate line is found this function will
 *  inject it into the TextureCoordinate-Array
 */
bool StaticModelData::addVertexTexture(float u, float v)
{
  PRINTF(5)("found vertex-Texture %f, %f\n", u, v);
  this->vTexture.push_back(u);
  this->vTexture.push_back(v);
  return true;
}

/**
 * @brief parses a face-string
 * @param faceString The String that will be parsed.
 *
 * If a face line is found this function will add it to the glList.
 *
 * String is different from the argument addFace,
 * in this, that the first Vertex/Normal/Texcoord is 1 instead of 0
 *
 * @TODO make it std::string conform
 */
bool StaticModelData::addFace (const std::string& faceStringInput)
{
  const char* faceString = faceStringInput.c_str();
  Face newFace;

  while(strcmp (faceString, "\0"))
  {
    FaceElement newElem;

    char tmpValue [50];
    int tmpLen;
    char* vertex = NULL;
    char* texture = NULL;
    char* normal = NULL;

    sscanf (faceString, "%s", tmpValue);
    tmpLen = strlen(tmpValue);
    vertex = tmpValue;

    if ((texture = strstr (vertex, "/")) != NULL)
    {
      texture[0] = '\0';
      texture ++;

      if ((normal = strstr (texture, "/")) !=NULL)
      {
        normal[0] = '\0';
        normal ++;
      }
    }
    if (vertex)
      newElem.vertexNumber = atoi(vertex)-1;
    if (texture)
      newElem.texCoordNumber = atoi(texture)-1;
    if (normal)
      newElem.normalNumber = atoi(normal)-1;

    faceString += tmpLen;
    if (strcmp (faceString, "\0"))
      faceString++;

    newFace._elements.push_back(newElem);
  }

  //this->currentGroup->faceCount += this->currentGroup->currentFace->vertexCount -2;
  _modelGroups.back()._faces.push_back(newFace);
  this->faceCount += newFace._elements.size() - 2;
  return true;
}

/**
 * @brief adds a new Face
 * @param faceElemCount the number of Vertices to add to the Face.
 * @param type The information Passed with each Vertex
*/
bool StaticModelData::addFace(int faceElemCount, VERTEX_FORMAT type, va_list args)
{
  Face newFace;

  for (int i = 0; i < faceElemCount; i++)
  {
    FaceElement newElem;

    newElem.vertexNumber = va_arg (args, int);
    if (type & TEXCOORD)
      newElem.texCoordNumber = va_arg (args, int);
    if (type & NORMAL)
      newElem.normalNumber = va_arg(args, int);

    newFace._elements.push_back(newElem);
  }

  //this->currentGroup->faceCount += this->currentGroup->currentFace->vertexCount -2;
  _modelGroups.back()._faces.push_back(newFace);
  this->faceCount += newFace._elements.size() - 2;
  return true;
}

/**
 * Function that selects a material, if changed in the obj file.
 * @param matString the Material that will be set.
*/
bool StaticModelData::setMaterial(const std::string& matString)
{
  Face matFace;
  matFace._material = this->findMaterialByName(matString);
  _modelGroups.back()._faces.push_back(matFace);

  return true;
}

/**
 * Function that selects a material, if changed in the obj file.
 * @param mtl the Material that will be set.
*/
bool StaticModelData::setMaterial(Material* mtl)
{
  Face matFace;
  matFace._material = mtl;
  _modelGroups.back()._faces.push_back(matFace);

  return true;
}

/**
 * @brief A routine that is able to create normals.
 *
 * The algorithm does the following:
 * 1. It calculates creates Vectors for each normale, and sets them to zero.
 * 2. It then Walks through a) all the Groups b) all the Faces c) all the FaceElements
 * 3. It searches for a points two neighbours per Face, takes Vecotrs to them calculates FaceNormals and adds it to the Points Normal.
 * 4. It goes through all the normale-Points and calculates the VertexNormale and includes it in the normals-Array.
 */
bool StaticModelData::buildVertexNormals ()
{
  PRINTF(4)("Normals are being calculated.\n");

  Vector* normArray = new Vector [vertices.size()/3];
  for (unsigned int i=0; i<vertices.size()/3;i++)
    normArray[i] = Vector(.0,.0,.0);

  Vector prevV;
  Vector nextV;
  Vector curV;

  for (std::vector<Group>::iterator group = _modelGroups.begin();
       group != _modelGroups.end();
       ++group)
  {
    for (std::vector<Face>::iterator face = (*group)._faces.begin();
         face != (*group)._faces.end();
         ++face)
    {
      if (!(*face)._elements.empty())
      {
        std::vector<FaceElement>::iterator firstElem = (*face)._elements.begin();
        std::vector<FaceElement>::iterator prevElem;
        std::vector<FaceElement>::iterator curElem = firstElem;
        std::vector<FaceElement>::iterator nextElem;
        std::vector<FaceElement>::iterator lastElem;

        // find last Element of the Chain.
        while (curElem != (*face)._elements.end())
        {
          prevElem = curElem;
          ++curElem;
        }
        lastElem = prevElem;

        curElem = firstElem;
        for (unsigned int j = 0; j < (*face)._elements.size(); j++)
        {
          nextElem = curElem;
          nextElem++;
          if (nextElem == (*face)._elements.end())
            nextElem = firstElem;
          (*curElem).normalNumber = (*curElem).vertexNumber;

          curV = Vector (this->vertices[(*curElem).vertexNumber*3],
                         this->vertices[(*curElem).vertexNumber*3+1],
                         this->vertices[(*curElem).vertexNumber*3+2]);

          prevV = Vector (this->vertices[(*prevElem).vertexNumber*3],
                          this->vertices[(*prevElem).vertexNumber*3+1],
                          this->vertices[(*prevElem).vertexNumber*3+2]) - curV;

          nextV = Vector (this->vertices[(*nextElem).vertexNumber*3],
                          this->vertices[(*nextElem).vertexNumber*3+1],
                          this->vertices[(*nextElem).vertexNumber*3+2]) - curV;
          normArray[(*curElem).vertexNumber] = normArray[(*curElem).vertexNumber] + nextV.cross(prevV);

          prevElem = curElem;
          ++curElem;
        }
      }
    }
  }

  for (unsigned int i=0; i < this->vertices.size()/3;i++)
  {
    normArray[i].normalize();
    PRINTF(5)("Found Normale number %d: (%f; %f, %f).\n", i, normArray[i].x, normArray[i].y, normArray[i].z);

    this->addVertexNormal(normArray[i].x, normArray[i].y, normArray[i].z);

  }
  delete[] normArray;
  return true;
}

////////////
// openGL //
////////////
/**
 *  reads and includes the Faces/Materials into the openGL state Machine
*/
bool StaticModelData::importToDisplayList()
{
  // finalize the Arrays
  if (normals.size() == 0) // vertices-Array must be built for this
    this->buildVertexNormals();

  for (std::vector<Group>::iterator group = _modelGroups.begin();
       group != _modelGroups.end();
       ++group)
  {

    // creating a glList for the Group
    if (((*group).listNumber = glGenLists(1)) == 0)
    {
      PRINTF(2)("glList could not be created for this Model\n");
      return false;
    }
    glNewList ((*group).listNumber, GL_COMPILE);

    // Putting Faces to GL
    for (std::vector<Face>::const_iterator face = (*group)._faces.begin();
         face != (*group)._faces.end();
         ++face)
    {
      if ((*face)._elements.empty() && (*face)._material != NULL)
      {
        if ((*group).faceMode != -1)
          glEnd();
        (*group).faceMode = 0;
        if ((*face)._material != NULL)
        {
          (*face)._material->select();
          PRINTF(5)("using material %s for coming Faces.\n", (*face)._material->getCName());
        }
      }

      else if ((*face)._elements.size() == 3)
      {
        if ((*group).faceMode != 3)
        {
          if ((*group).faceMode != -1)
            glEnd();
          glBegin(GL_TRIANGLES);
        }

        (*group).faceMode = 3;
        PRINTF(5)("found triag.\n");
      }

      else if ((*face)._elements.size() == 4)
      {
        if ((*group).faceMode != 4)
        {
          if ((*group).faceMode != -1)
            glEnd();
          glBegin(GL_QUADS);
        }
        (*group).faceMode = 4;
        PRINTF(5)("found quad.\n");
      }

      else if ((*face)._elements.size() > 4)
      {
        if ((*group).faceMode != -1)
          glEnd();
        glBegin(GL_POLYGON);
        PRINTF(5)("Polygon with %i faces found.", (*face)._elements.size());
        (*group).faceMode = (*face)._elements.size();
      }

      for (std::vector<FaceElement>::const_iterator elem = (*face)._elements.begin();
           elem != (*face)._elements.end();
           ++elem)
      {
        //      PRINTF(2)("%s\n", (*elem).value);
        this->addGLElement(*elem);
      }
    }
    glEnd();
    glEndList();

  }
  return true;
}


/**
 *  builds an array of triangles, that can later on be used for obb separation and octree separation
 */
bool StaticModelData::buildTriangleList()
{
  if( unlikely(!this->triangles.empty()))
    return true;
  /* make sure, that all the arrays are finalized */
  if( normals.size() == 0) // vertices-Array must be built for this
    this->buildVertexNormals();

  int                index = 0;                   //!< the counter for the triangle array
  unsigned int numTriangles = 0;
  bool warned = false;

  /* count the number of triangles */
  /* now iterate through all groups and build up the triangle list */
  for (std::vector<Group>::iterator group = _modelGroups.begin();
       group != _modelGroups.end();
       ++group)
  {
    for (std::vector<Face>::const_iterator face = (*group)._faces.begin();
         face != (*group)._faces.end();
         ++face)
    {
      /* if its a triangle just add it to the list */
      if( (*face)._elements.size() == 3)
      {
        ++numTriangles;
      } /* if the polygon is a quad */
      else if((*face)._elements.size() == 4)
      {
        numTriangles += 2;
      }
      else if( (*face)._elements.size() > 4)
      {
        if (!warned)
        {
          PRINTF(2)("This model (%s) got over 4 vertices per face <=> conflicts in the CD engine!\n", this->getCName());
          warned = true;
        }
      }
    }
  }

  PRINTF(3)("got %i triangles, %i vertices\n", numTriangles, this->vertices.size());


  /* write MODELINFO structure */

  /* allocate memory for the new triangle structures */
  this->triangles.resize(numTriangles);

  /* now iterate through all groups and build up the triangle list */
  for (std::vector<Group>::iterator group = _modelGroups.begin();
       group != _modelGroups.end();
       ++group)
  {
    for (std::vector<Face>::const_iterator face = (*group)._faces.begin();
         face != (*group)._faces.end();
         ++face)
    {
      /* if its a triangle just add it to the list */
      if( (*face)._elements.size() == 3)
      {
        unsigned int j = 0;
        for (std::vector<FaceElement>::const_iterator elem = (*face)._elements.begin();
             elem != (*face)._elements.end();
             ++elem)
        {
          this->triangles[index].indexToVertices[j] = (unsigned int)(*elem).vertexNumber * 3;
          this->triangles[index].indexToNormals[j] = (unsigned int)(*elem).normalNumber * 3;
          this->triangles[index].indexToTexCoor[j] = (unsigned int)(*elem).texCoordNumber * 3;
          ++j;
        }
        ++index;
      } /* if the polygon is a quad */

      else if( (*face)._elements.size() == 4)
      {
        std::vector<FaceElement>::const_iterator elem = (*face)._elements.begin();

        this->triangles[index].indexToVertices[0] = (unsigned int)(*elem).vertexNumber * 3;
        this->triangles[index].indexToNormals[0] = (unsigned int)(*elem).normalNumber * 3;
        this->triangles[index].indexToTexCoor[0] = (unsigned int)(*elem).texCoordNumber * 3;

        this->triangles[index + 1].indexToVertices[0] = (unsigned int)(*elem).vertexNumber * 3;
        this->triangles[index + 1].indexToNormals[0] = (unsigned int)(*elem).normalNumber * 3;
        this->triangles[index + 1].indexToTexCoor[0] = (unsigned int)(*elem).texCoordNumber * 3;
        ++elem;

        this->triangles[index].indexToVertices[1] = (unsigned int)(*elem).vertexNumber * 3;
        this->triangles[index].indexToNormals[1] = (unsigned int)(*elem).normalNumber * 3;
        this->triangles[index].indexToTexCoor[1] = (unsigned int)(*elem).texCoordNumber * 3;
        ++elem;

        this->triangles[index].indexToVertices[2] = (unsigned int)(*elem).vertexNumber * 3;
        this->triangles[index].indexToNormals[2] = (unsigned int)(*elem).normalNumber * 3;
        this->triangles[index].indexToTexCoor[2] = (unsigned int)(*elem).texCoordNumber * 3;

        this->triangles[index + 1].indexToVertices[2] = (unsigned int)(*elem).vertexNumber * 3;
        this->triangles[index + 1].indexToNormals[2] = (unsigned int)(*elem).normalNumber * 3;
        this->triangles[index + 1].indexToTexCoor[2] = (unsigned int)(*elem).texCoordNumber * 3;
        ++elem;

        this->triangles[index + 1].indexToVertices[1] = (unsigned int)(*elem).vertexNumber * 3;
        this->triangles[index + 1].indexToNormals[1] = (unsigned int)(*elem).normalNumber * 3;
        this->triangles[index + 1].indexToTexCoor[1] = (unsigned int)(*elem).texCoordNumber * 3;

        index += 2;
      }
    }
  }
  return true;
}


/**
 *  Adds a Face-element (one vertex of a face) with all its information.
 * @param elem The FaceElement to add to the OpenGL-environment.

   It does this by searching:
   1. The Vertex itself
   2. The VertexNormale
   3. The VertexTextureCoordinate
   merging this information, the face will be drawn.
*/
bool StaticModelData::addGLElement (const FaceElement& elem)
{
  PRINTF(5)("importing grafical Element to openGL.\n");

  if (elem.texCoordNumber > -1)
  {
    if (likely((unsigned int)elem.texCoordNumber < this->vTexture.size()))
      glTexCoord2fv(&this->vTexture[0] + elem.texCoordNumber * 2);
    else
      PRINTF(2)("TextureCoordinate %d is not in the List (max: %d)\nThe Model might be incomplete\n",
                elem.texCoordNumber, this->vTexture.size());
  }
  if (elem.normalNumber > -1)
  {
    if (likely((unsigned int)elem.normalNumber < this->normals.size()))
      glNormal3fv(&this->normals[0] + elem.normalNumber * 3);
    else
      PRINTF(2)("Normal %d is not in the List (max: %d)\nThe Model might be incomplete",
                elem.normalNumber, this->normals.size());
  }
  if (elem.vertexNumber > -1)
  {
    if (likely((unsigned int)elem.vertexNumber < this->vertices.size()))
      glVertex3fv(&this->vertices[0]+ elem.vertexNumber * 3);
    else
      PRINTF(2)("Vertex %d is not in the List (max: %d)\nThe Model might be incomplete",
                elem.vertexNumber, this->vertices.size());
  }

  return true;
}