Hi guys,
I have an arrayList called model which contains 3 other arrayLists called modelPart. modelPart are arrayLists of PVectors.
I would like to join all the PVectors of the 3 arrayLists modelParts in one new arrayList called nodes, but I don't know the correct syntax. Here is the code bit:

class Model
{
  ArrayList <ModelPart> model;

  Model()
  {
    model = new ArrayList<ModelPart>();
  }
}

class ModelPart
{
  ArrayList nodes;

  ModelPart(ArrayList<PVector> p)
  {
    nodes = new ArrayList();
    getPoints(p);
  }

  void getPoints(ArrayList<PVector> p)
  {
    for(int i = 0; i < mod.model.size(); ++i)
    {
      nodes.add(threshold.points);
    }
  }

  void draw()
  {
    threshold.display();
   
    nodes.clear();
///////////////////////////////////////////////this is my last bad tentative/////////////
    for(int i = 0; i < mod.model.size(); ++i)
    {
      ModelPart mopa = mod.model.get(i);
      for(int j = 0; j < mopa.threshold.points.size(); j++)
      {
        KinectThreshold n = (KinectThreshold)threshold.points.get(i);
        nodes.add(n);
      }
    }
///////////////////////////////////////////////////////////////////////////////////////////////////   
    println(nodes.size());
  }
}

main:

void draw()
{
  for(int i = 0; i < mod.model.size(); i++)
  {
    ModelPart mp = mod.model.get(i);
    mp.draw();
  }
}

void keyPressed()
{
  if(key == ' ')
  {
    if (mod.model.size() < 3)
    {
      mod.model.add(new ModelPart(threshold.points)); //the vectors are coming form a threshold class with points
    }
  }
}

thanks for your help in advance :)