  In the process of product design and digital fabrication, the structural
analysis of a designed prototype is a fundamental and essential step. However,
such a step is usually invisible or inaccessible to designers at the early
sketching phase. This limits the user's ability to consider a shape's physical
properties and structural soundness. To bridge this gap, we introduce a novel
approach Sketch2Stress that allows users to perform structural analysis of
desired objects at the sketching stage. This method takes as input a 2D
freehand sketch and one or multiple locations of user-assigned external forces.
With the specially-designed two-branch generative-adversarial framework, it
automatically predicts a normal map and a corresponding structural stress map
distributed over the user-sketched underlying object. In this way, our method
empowers designers to easily examine the stress sustained everywhere and
identify potential problematic regions of their sketched object. Furthermore,
combined with the predicted normal map, users are able to conduct a region-wise
structural analysis efficiently by aggregating the stress effects of multiple
forces in the same direction. Finally, we demonstrate the effectiveness and
practicality of our system with extensive experiments and user studies.
