  We develop an optimization-based method to model smocking, a surface
embroidery technique that provides decorative geometric texturing while
maintaining stretch properties of the fabric. During smocking, multiple pairs
of points on the fabric are stitched together, creating non-manifold geometric
features and visually pleasing textures. Designing smocking patterns is
challenging, because the outcome of stitching is unpredictable: the final
texture is often revealed only when the whole smocking process is completed,
necessitating painstaking physical fabrication and time consuming
trial-and-error experimentation. This motivates us to seek a digital smocking
design method. Straightforward attempts to compute smocked fabric geometry
using surface deformation or cloth simulation methods fail to produce realistic
results, likely due to the intricate structure of the designs, the large number
of contacts and high-curvature folds. We instead formulate smocking as a graph
embedding and shape deformation problem. We extract a coarse graph representing
the fabric and the stitching constraints, and then derive the graph structure
of the smocked result. We solve for the 3D embedding of this graph, which in
turn reliably guides the deformation of the high-resolution fabric mesh. Our
optimization based method is simple, efficient, and flexible, which allows us
to build an interactive system for smocking pattern exploration. To demonstrate
the accuracy of our method, we compare our results to real fabrications on a
large set of smocking patterns
