  Shape retrieval and alignment are a promising avenue towards turning 3D scans
into lightweight CAD representations that can be used for content creation such
as mobile or AR/VR gaming scenarios. Unfortunately, CAD model retrieval is
limited by the availability of models in standard 3D shape collections (e.g.,
ShapeNet). In this work, we address this shortcoming by introducing CAD-Deform,
a method which obtains more accurate CAD-to-scan fits by non-rigidly deforming
retrieved CAD models. Our key contribution is a new non-rigid deformation model
incorporating smooth transformations and preservation of sharp features, that
simultaneously achieves very tight fits from CAD models to the 3D scan and
maintains the clean, high-quality surface properties of hand-modeled CAD
objects. A series of thorough experiments demonstrate that our method achieves
significantly tighter scan-to-CAD fits, allowing a more accurate digital
replica of the scanned real-world environment while preserving important
geometric features present in synthetic CAD environments.
