Added get_shape_at_point() for PCA expression models

patrikhuber · Jan 29, 2024 · 3276019 · 3276019
1 parent 61ccbcb
commit 3276019
Showing 1 changed file with 41 additions and 0 deletions.
diff --git a/include/eos/fitting/ceres_nonlinear.hpp b/include/eos/fitting/ceres_nonlinear.hpp
@@ -44,6 +44,12 @@ Eigen::Vector3<T> get_shape_at_point(const eos::morphablemodel::PcaModel& shape_
                                      Eigen::Map<const Eigen::VectorX<T>> shape_coeffs,
                                      Eigen::Map<const Eigen::VectorX<T>> blendshape_coeffs);
 
+template <typename T>
+Eigen::Vector3<T> get_shape_at_point(const eos::morphablemodel::PcaModel& shape_model,
+                                     const eos::morphablemodel::PcaModel& expression_model, int vertex_id,
+                                     Eigen::Map<const Eigen::VectorX<T>> shape_coeffs,
+                                     Eigen::Map<const Eigen::VectorX<T>> expression_coeffs);
+
 template <typename T>
 Eigen::Vector3<T> get_vertex_color_at_point(const eos::morphablemodel::PcaModel& color_model, int vertex_id,
                                             Eigen::Map<const Eigen::VectorX<T>> color_coeffs);
@@ -402,6 +408,41 @@ Eigen::Vector3<T> get_shape_at_point(const eos::morphablemodel::PcaModel& shape_
     return Eigen::Vector3<T>(mean.cast<T>() + shape_vector + expression_vector);
 };
 
+/**
+ * Returns the 3D position of a single point of the 3D shape generated by the parameters given.
+ *
+ * @param[in] shape_model A PCA 3D shape model.
+ * @param[in] expression_model A PCA 3D expression model.
+ * @param[in] vertex_id Vertex id of the 3D model that should be projected.
+ * @param[in] shape_coeffs A set of PCA shape coefficients used to generate the point.
+ * @param[in] expression_coeffs A set of expression coefficients used to generate the point.
+ * @return The 3D point.
+ */
+template <typename T>
+Eigen::Vector3<T> get_shape_at_point(const eos::morphablemodel::PcaModel& shape_model,
+                                     const eos::morphablemodel::PcaModel& expression_model, int vertex_id,
+                                     Eigen::Map<const Eigen::VectorX<T>> shape_coeffs,
+                                     Eigen::Map<const Eigen::VectorX<T>> expression_coeffs)
+{
+    // Computing Shape = shape_mean + shape_basis*shape_coeffs +
+    //                   expression_mean + expression_basis*expression_coeffs:
+    const Eigen::Vector3f shape_mean = shape_model.get_mean_at_point(vertex_id);
+    const Eigen::Vector3f expression_mean = expression_model.get_mean_at_point(vertex_id);
+    // Note: We seem to have a dependent name here, so we need 'template', to help the compiler that 'cast<T>'
+    // is a template.
+    const Eigen::Vector3<T> shape_vector = shape_model.get_rescaled_pca_basis_at_point(vertex_id)
+                                               .leftCols(shape_coeffs.size())
+                                               .template cast<T>() *
+                                           shape_coeffs;
+    const Eigen::Vector3<T> expression_vector = expression_model.get_rescaled_pca_basis_at_point(vertex_id)
+                                                    .leftCols(expression_coeffs.size())
+                                                    .template cast<T>() *
+                                                expression_coeffs;
+
+    return Eigen::Vector3<T>(shape_mean.cast<T>() + shape_vector + expression_mean.cast<T>() +
+                             expression_vector);
+};
+
 /**
  * Returns the colour value of a single point of the 3D model generated by the parameters given.
  *