Method SimulateEdgeStep

Infovis/BoostGraphAlgorithms/vtkBoostDividedEdgeBundling.cxx:366–489

}

void vtkBundlingMetadata::SimulateEdgeStep()
{
  vtkIdType numEdges = this->Graph->GetNumberOfEdges();

  for (vtkIdType e1 = 0; e1 < numEdges; ++e1)
  {
    float weight1 = 1.0f;
    for (int m1 = 0; m1 < this->MeshCount; ++m1)
    {
      // Immovable
      if (m1 <= 0 || m1 >= this->MeshCount - 1)
      {
        continue;
      }

      // Move the point according to dynamics
      vtkVector3f position = this->EdgeMesh[e1][m1];
      vtkVector3f velocity = this->EdgeMeshVelocities[e1][m1];
      vtkVector3f acceleration = this->EdgeMeshAccelerations[e1][m1];
      velocity = velocity + acceleration * this->SimulationStep * 0.5f;
      velocity = velocity * this->VelocityDamping;
      position = position + velocity * this->SimulationStep;
      this->EdgeMesh[e1][m1] = position;

      acceleration = vtkVector3f(0.0f, 0.0f, 0.0f);

      // Spring force
      vtkVector3f prevPosition = this->EdgeMesh[e1][m1 - 1];
      vtkVector3f prevDirection = prevPosition - position;
      float prevDist = prevDirection.Norm();
      float prevForce =
        this->EdgeSpringConstant / 1000.0f * (this->MeshCount - 1) * prevDist * weight1;
      prevDirection.Normalize();
      acceleration = acceleration + prevForce * prevDirection;

      vtkVector3f nextPosition = this->EdgeMesh[e1][m1 + 1];
      vtkVector3f nextDirection = nextPosition - position;
      float nextDist = nextDirection.Norm();
      float nextForce =
        this->EdgeSpringConstant / 1000.0f * (this->MeshCount - 1) * nextDist * weight1;
      nextDirection.Normalize();
      acceleration = acceleration + nextForce * nextDirection;

      // Coulomb force
      float normalizedEdgeCoulombConstant =
        this->EdgeCoulombConstant / sqrt(static_cast<float>(numEdges));

      for (vtkIdType e2 = 0; e2 < numEdges; ++e2)
      {
        if (e1 == e2)
        {
          continue;
        }

        float compatibility = this->EdgeCompatibilities[e1][e2];
        if (compatibility <= 0.05)
        {
          continue;