  It is common in graphic design humans visually arrange various elements
according to their design intent and semantics. For example, a title text
almost always appears on top of other elements in a document. In this work, we
generate graphic layouts that can flexibly incorporate such design semantics,
either specified implicitly or explicitly by a user. We optimize using the
latent space of an off-the-shelf layout generation model, allowing our approach
to be complementary to and used with existing layout generation models. Our
approach builds on a generative layout model based on a Transformer
architecture, and formulates the layout generation as a constrained
optimization problem where design constraints are used for element alignment,
overlap avoidance, or any other user-specified relationship. We show in the
experiments that our approach is capable of generating realistic layouts in
both constrained and unconstrained generation tasks with a single model. The
code is available at https://github.com/ktrk115/const_layout .
