Abstract: Recent years have witnessed rapid development of digital fabrication techniques，causing manufacturing individual models to be accessible to ordinary users． Thus designing tools for customized objects along a user- friendly way is getting highly demanded． Inspired by texture synthesis and image mosaics，this paper proposes a method that generates an editable patterns collage design along a given boundary: users’inputting a close curve as the boundary and several pattern units; the method firstly generates an initial patterns collage design along the giv- en curve boundary automatically; then users can directly edit each pattern unit; adjustment of patterns collage lay- out would take place on the basis of a spring mass system meanwhile maintaining the boundary constraint automati- cally． After the whole interaction step，our method optimizes the collage result for local connectivity in order to meet the fabrication constraints，so that we can manufacture this design by digital fabrications such as 3D printing and digital cutting． To demonstrate the effectiveness，we show the fabricated results via 3D printing and digital pa- per cutting．

Key words: pattern collage, boundary-constrained, auto-collage, interactive design