EmbroForm: Digital Fabrication of Soft Freeform Objects with Machine Embroidered Pull-up Strings

Pull-up objects form 3D shapes by pulling a string routed through a 2D material, offering low-cost 2D fabrication and reversible transformation. However, existing approaches rely on origamic folding, which creates faceted, oftentimes rigid surfaces and requires manual pull-up string routing. We introduce EmbroForm, a digital fabrication pipeline for fully soft pull-up objects with organic, higher-fidelity shapes. Instead of folding, EmbroForm forms 3D shapes by seaming the boundaries of a flexible 2D patch unwrapped from the target. To enable this, we contribute a fabrication technique that automates the routing of sliding strings on flexible sheet materials with machine embroidery, which we extend on to design zig-zag lacings for seaming the boundaries. Then we introduce an end-to-end pipeline that, given a 3D mesh, creates an optimized 2D unwrapped patch and generates pull-up string routing paths for fabrication. We provide a design tool for customization and validate our approach with technical experiments and implemented application cases.