In this work we present a complete pipeline to convert CAD models into smooth G1 spline representations, which are suitable for isogeometric analysis. Starting from a CAD boundary representation of a mechanical object, we perform an automatic control cage extraction by means of quadrangular faces, such that its limit Catmull-Clark subdivision surface approximates accurately the input model. Then we compute a basis of the G1 spline space over the quad mesh in order to carry out least squares fitting over a point cloud, acquired by sampling the original CAD geometry. The resulting surface is a collection of Bézier patches with G1 regularity, except at the sharp edges. Finally, we use the basis functions to perform isogeometric analysis simulations of realistic PDEs on the reconstructed G1 model. The quality of the construction is demonstrated via several numerical examples performed on a collection of CAD objects presenting various challenging realistic shapes.