message: Core: fixed multi-image bug in VP Optimizer.
  This is of course now specialized to coupled images, as otherwise the projections now do not make sense.
diff: @@ -17,6 +17,8 @@ namespace Engine
  void Optimizer_VP::Iteration()
  {
  std::shared_ptr<Data::Spin_System> s;
  + scalar projection_full = 0;
  + scalar force_norm2_full = 0;
  // Set previous
  for (int i = 0; i < noi; ++i)
  @@ -45,16 +47,31 @@ namespace Engine
  // Get the projection of the velocity on the force
  projection[i] = Vectormath::dot(l_velocity, l_force);
  force_norm2[i] = Vectormath::dot(l_force, l_force);
  + }
  + for (int i = 0; i < noi; ++i)
  + {
  + projection_full += projection[i];
  + force_norm2_full += force_norm2[i];
  + }
  + for (int i = 0; i < noi; ++i)
  + {
  + auto& l_velocity = velocity[i];
  + auto& l_force = force[i];
  + auto& l_force_prev = force_previous[i];
  + auto& configuration = *(configurations[i]);
  +
  + s = method->systems[i];
  + scalar dt = s->llg_parameters->dt;
  // Calculate the projected velocity
  - if (projection[i] <= 0)
  + if (projection_full <= 0)
  {
  Vectormath::fill(l_velocity, { 0,0,0 });
  }
  else
  {
  Vectormath::set_c_a(1.0, l_force, l_velocity);
  - Vectormath::scale(l_velocity, projection[i] / force_norm2[i]);
  + Vectormath::scale(l_velocity, projection_full / force_norm2_full);
  }
  // Copy in
  