message: UI-QT: fixed bug with 2D multi-atom basis surface visualisation.
  The surface renderer would be created from a default geometry, which would however not work in 2D, so that it would crash with a qhull error.
diff: @@ -232,12 +232,27 @@ void SpinWidget::initializeGL()
  if (Geometry_Get_Dimensionality(this->state.get()) == 2)
  + {
  + // Determine orthogonality of translation vectors
  + float ta[3], tb[3], tc[3];
  + Geometry_Get_Translation_Vectors(state.get(), ta, tb, tc);
  + float tatb = 0, tatc = 0, tbtc = 0;
  + for (int dim = 0; dim<3; ++dim)
  + {
  + tatb += ta[dim] * tb[dim];
  + tatc += ta[dim] * tc[dim];
  + tbtc += tb[dim] * tc[dim];
  + }
  + // Rectilinear with one basis atom
  + if (Geometry_Get_N_Basis_Atoms(state.get()) == 1 &&
  + std::abs(tatb) < 1e-8 && std::abs(tatc) < 1e-8 && std::abs(tbtc) < 1e-8)
  {
  // 2D Surface options
  // No options yet...
  this->m_renderer_surface_2D = std::make_shared<VFRendering::SurfaceRenderer>(m_view);
  this->m_renderer_surface = m_renderer_surface_2D;
  }
  + }
  else if (Geometry_Get_Dimensionality(this->state.get()) == 3)
  {
  // 3D Surface options
  @@ -367,7 +382,7 @@ void SpinWidget::updateData()
  }
  }
  - else if (Geometry_Get_Dimensionality(state.get()) < 2)
  + else
  {
  geometry = VFRendering::Geometry(positions, {}, {}, true);
  }
  