  A key step during industrial design is the passing of design information from
computer aided design (CAD) to analysis tools (CAE) and vice versa. Here, one
is faced with a severe incompatibility in geometry representation: While CAD is
usually based on surface representations, analysis mostly relies on volumetric
representations. The forward pass, i.e., converting CAD data to computational
meshes, is well understood and established. However, the same does not hold for
the inverse direction, i.e., CAD reconstruction of deformed geometries
resulting, e.g., from shape optimization. The few reconstruction methods
reported mainly rely on spline fitting, in particular methods that rely on
creating new splines simililar to shape reconstruction from 3D imaging. In
contrast, this paper studies a novel approach that reuses the CAD data given in
the initial design. We show that this concept leads to precise shape
reconstructions while also preserving the initial notion of features defined
during design. Furthermore, reusing the initial CAD representation reduces the
shape reconstruction problem to a shape modification problem. We study this
unique feature and show that it enables the reconstruction of CAD data from
computational meshes by composing each spline in the initial CAD data with a
single, global deformation spline. While post-processing is needed for use in
current CAD software, this novel approach not only allows creating watertight
models, but also enables reconstructing complete CAD models even from
defeatured computational meshes.
