Remove blendshapes argument from fit_shape_and_pose in Python

It was unused and caused a bad optional access because the expression model wasn't passed in.
Updated the demo.py script accordingly.

Author: patrikhuber

python/demo.py

@@ -10,14 +10,17 @@ def main():
 
     model = eos.morphablemodel.load_model("../share/sfm_shape_3448.bin")
     blendshapes = eos.morphablemodel.load_blendshapes("../share/expression_blendshapes_3448.bin")
+    # Create a MorphableModel with expressions from the loaded neutral model and blendshapes:
+    morphablemodel_with_expressions = eos.morphablemodel.MorphableModel(model.get_shape_model(), blendshapes,
+                                                                        eos.morphablemodel.PcaModel(),
+                                                                        model.get_texture_coordinates())
     landmark_mapper = eos.core.LandmarkMapper('../share/ibug_to_sfm.txt')
     edge_topology = eos.morphablemodel.load_edge_topology('../share/sfm_3448_edge_topology.json')
     contour_landmarks = eos.fitting.ContourLandmarks.load('../share/ibug_to_sfm.txt')
     model_contour = eos.fitting.ModelContour.load('../share/sfm_model_contours.json')
 
-    (mesh, pose, shape_coeffs, blendshape_coeffs) = eos.fitting.fit_shape_and_pose(model, blendshapes,
-        landmarks, landmark_ids, landmark_mapper,
-        image_width, image_height, edge_topology, contour_landmarks, model_contour)
+    (mesh, pose, shape_coeffs, blendshape_coeffs) = eos.fitting.fit_shape_and_pose(morphablemodel_with_expressions,
+        landmarks, landmark_ids, landmark_mapper, image_width, image_height, edge_topology, contour_landmarks, model_contour)
 
     # Now you can use your favourite plotting/rendering library to display the fitted mesh, using the rendering
     # parameters in the 'pose' variable.

python/generate-python-bindings.cpp

@@ -247,7 +247,6 @@ PYBIND11_MODULE(eos, eos_module)
     fitting_module.def(
         "fit_shape_and_pose",
         [](const morphablemodel::MorphableModel& morphable_model,
-           const std::vector<morphablemodel::Blendshape>& blendshapes,
            const std::vector<Eigen::Vector2f>& landmarks, const std::vector<std::string>& landmark_ids,
            const core::LandmarkMapper& landmark_mapper, int image_width, int image_height,
            const morphablemodel::EdgeTopology& edge_topology,
@@ -274,8 +273,8 @@ PYBIND11_MODULE(eos, eos_module)
         },
         "Fit the pose (camera), shape model, and expression blendshapes to landmarks, in an iterative way. "
         "Returns a tuple (mesh, rendering_parameters, shape_coefficients, blendshape_coefficients).",
-        py::arg("morphable_model"), py::arg("blendshapes"), py::arg("landmarks"), py::arg("landmark_ids"),
-        py::arg("landmark_mapper"), py::arg("image_width"), py::arg("image_height"), py::arg("edge_topology"),
+        py::arg("morphable_model"), py::arg("landmarks"), py::arg("landmark_ids"), py::arg("landmark_mapper"),
+        py::arg("image_width"), py::arg("image_height"), py::arg("edge_topology"),
         py::arg("contour_landmarks"), py::arg("model_contour"), py::arg("num_iterations") = 5,
         py::arg("num_shape_coefficients_to_fit") = py::none(), py::arg("lambda_identity") = 30.0f,
         py::arg("num_expression_coefficients_to_fit") = py::none(), py::arg("lambda_expressions") = 30.0f);