* @param[in] morphable_model The Morphable Model whose shape (coefficients) are estimated.
* @param[in] morphable_model The Morphable Model whose shape (coefficients) are estimated.
* @param[in] affine_camera_matrix A 3x4 affine camera matrix from model to screen-space (should probably be of type CV_32FC1 as all our calculations are done with float).
* @param[in] affine_camera_matrix A 3x4 affine camera matrix from model to screen-space (should probably be of type CV_32FC1 as all our calculations are done with float).
* @param[in] landmarks 2D landmarks from an image, given in clip-coordinates.
* @param[in] landmarks 2D landmarks from an image to fit the model to.
* @param[in] vertex_ids The vertex ids in the model that correspond to the 2D points.
* @param[in] vertex_ids The vertex ids in the model that correspond to the 2D points.
* @param[in] lambda The regularisation parameter (weight of the prior towards the mean).
* @param[in] lambda The regularisation parameter (weight of the prior towards the mean).
* @param[in] num_coefficients_to_fit How many shape-coefficients to fit (all others will stay 0). Not tested thoroughly.
* @param[in] num_coefficients_to_fit How many shape-coefficients to fit (all others will stay 0). Not tested thoroughly.