message: Changed behaviour of MorphableModel::get_mean to return the overall shape *and* expression mean
diff: @@ -132,9 +132,10 @@ public:
  }
  /**
  - * Returns the mean of the shape- and colour model as a Mesh.
  + * Returns the mean of the shape (identity, and expressions, if present) and colour model as a Mesh.
  *
  - * If the model contains a separate PCA expression model, that mean is not added here.
  + * If the model contains a separate PCA expression model, the mean of that model is added and the overall
  + * shape mean is returned.
  *
  * @return An mesh instance of the mean of the Morphable Model.
  */
  @@ -144,9 +145,16 @@ public:
  !has_color_model()); // The number of vertices (= model.getDataDimension() / 3) has to be equal
  // for both models, or, alternatively, it has to be a shape-only model.
  - const Eigen::VectorXf shape = shape_model.get_mean();
  + Eigen::VectorXf shape = shape_model.get_mean();
  const Eigen::VectorXf color = color_model.get_mean();
  + // If there is a PCA expression model, add that model's mean. If there is no expression model, or
  + // blendshapes, there's nothing to add.
  + if (get_expression_model_type() == ExpressionModelType::PcaModel)
  + {
  + shape += cpp17::get<PcaModel>(expression_model.value()).get_mean();
  + }
  +
  core::Mesh mesh;
  if (has_texture_coordinates())
  {
  