FROM STITCHES TO DIGITS AND BACK: COMPUTATIONAL CROCHETING OF BRANCHING GEOMETRIES

Abstract

Crocheting is a hands-on craft that involves repetitive manipulation of a single continuous thread with a hook-like tool to generate surfaces and 3D forms. In a previous study, we have presented a parametric model [1] that generates crochet patterns of NURBS surfaces using a 10-stitches-by-10-rows swatch to account for all the physical variables that affect the crocheted object (i.e., yarn thickness, hook size, crafter’s grip). The dimensions of the previously crocheted tension swatches were used as the inputs of the crochet pattern generator algorithm, alongside the desired NURBS geometry, to generate individualized crochet patterns. These crochet patterns are text-based representations, similar to g-code in additive manufacturing, enabling the documentation and communication of the step-by-step hands-on crocheting process. Following these crochet patterns, the users can crochet physical objects with the same dimensions and form as their digitally modeled counterparts. This paper presents the second stage of this research in which we expanded this computational framework to enable crocheting of parametric branching geometries with multiple components by multiple crafters. While the components of the branching geometries can be crocheted by a single user, it is also possible to have different users crochet the components since the tension swatch can capture crafter-specific variables. As a proof-of-concept, a branching structure made of 14 unique components is designed and crocheted by two students of architecture as part of the Advanced Digital Fabrication course at the Pennsylvania State University. The students each crocheted 7 components based on their individual inputs while maintaining the dimensions and form of the digitally designed branching geometry. The findings suggest the possibility of a collective and distributed crocheting platform which can be used to create crocheted artifacts in various scales. This can be considered an alternative way to transition from the digital to the physical without relying on digital fabrication tools.

Keywords

• Digital Craft
• Computational Making
• Crocheting
• Soft Fabrication
• Digital Fabrication.

References

1. [1] Çapunaman ÖB, Bingöl CK, Gürsoy B. Computing Stitches and Crocheting Geometry. Çağdaş G, Özkar M, Gül LF, Gürer E, editors. Computer-Aided Architectural Design. Future Trajectories Springer; 2017; 289–305. https://doi.org/10.1007/978-981-10-5197-5_16.
2. [2] Bernasconi A, Bodei C & Pagli L. (2007). Knitting for Fun: A Recursive Sweater. In P. Crescenzi, G. Prencipe, & G. Pucci (Eds.), Fun with Algorithms (pp. 53–65). Springer. https://doi.org/10.1007/978-3-540-72914-3_7
3. [3] Taimina D, Baurmann G. Crocheting Algorithm. Cornell Journal of Architecture 2013.
4. [4] Worden A. Emergent Explorations: Analog and Digital Scripting. Thesis. Virginia Tech, 2011.
5. [5] Kenning G. Crochet Lace as Expression of Digital Culture. Textile Society of America Symposium Proceedings. 2008.
6. [6] Kucukoglu JG, Colakoglu B. Algorithmic Form Generation for Crochet Technique. Proceedings of the 31st eCAADe Conference 2013; 2: 273–8.
7. [7] Ahlquist S, Menges A. Frameworks for Computational Design of Textile Micro-Architectures and Material Behavior in Forming Complex Force-Active Structures. Proceedings of the 33rd Annual Conference of the Association for Computer Aided Design in Architecture (ACADIA) 2013; 281–92.
8. [8] Baranovskaya Y. Knitflatable Architecture - Pneumatically Activated Preprogrammed Knitted Textiles. Proceedings of the 34th eCAADe Conference 2016; 1: 571–80.

9. [9] McKnelly CL. Knitting behavior : a material-centric design process. Thesis. Massachusetts Institute of Technology, 2015.
10. [10] Oghazian F, Vazquez E. A Multi-Scale Workflow for Designing with New Materials in Architecture: Case Studies across Materials and Scales - Case studies across materials and scales. Proceedings of the 26th CAADRIA Conference 2021; 1: 533–42.
11. [11] Sabin J, Pranger D, Binkley C, Strobel K, Liu J. Lumen. Proceedings of the 38th Annual Conference of the Association for Computer Aided Design in Architecture (ACADIA) 2018; 444–55.
12. [12] Thomsen MRT. Knit as bespoke material practice for architecture. ACADIA // 2016: POSTHUMAN FRONTIERS: Data, Designers, and Cognitive Machines [Proceedings of the 36th Annual Conference of the Association for Computer Aided Design in Architecture (ACADIA) 2016; 280-289
13. [13] Pal A, Chan WL, Tan YY, Chia PZ, Tracy KJ. Knit Concrete Formwork. Proceedings of the 25th CAADRIA Conference 2020; 1: 213–22.
14. [14] Popescu M, Reiter L, Liew A, Van Mele T, Flatt RJ, Block P. Building in Concrete with an Ultra-lightweight Knitted Stay-in-place Formwork: Prototype of a Concrete Shell Bridge. Structures 2018; 14: 322–32. https://doi.org/10.1016/j.istruc.2018.03.001.
15. [15] Popescu M, Rippmann M, Liew A, Reiter L, Flatt RJ, Van Mele T, et al. Structural design, digital fabrication and construction of the cable-net and knitted formwork of the KnitCandela concrete shell. Structures 2021; 31: 1287–99. https://doi.org/10.1016/j.istruc.2020.02.013.
16. [16] Spiers M. Knitting vs. Crochet: what’s the difference? 2021. https://www.gathered.how/knitting-and-crochet/crochet/crochet-vs-knitting-difference/
17. [17] Henderson DW, Taimina D. Crocheting the hyperbolic plane. The Mathematical Intelligencer 2001; 23:17–28. https://doi.org/10.1007/BF03026623.
18. [18] Osinga H, Krauskopf B. Crocheting the Lorenz Manifold. The Mathematical Intelligencer 2004; 26. https://doi.org/10.1007/BF02985416.
19. [19] Avtanski A. Crochet Lathe2016. http://avtanski.net/projects/crochet/lathe/.
20. [20] Monroe A. Knittink’s Amigurumi Pattern Maker Falls Short 2010. https://audreymonroe.wordpress.com/2010/10/05/knittinks-amigurumi-pattern-maker-falls-short/
21. [21] Von Buelow P. A Geometric Comparison of Branching Structures in Tension and in Compression versus Minimal Paths 2007.
22. [22] Vestartas P. Minimal Path Networks. McNeel Forum 2019. https://discourse.mcneel.com/t/minimal-path-networks/57158/32.
23. [23] MultiPipe 2021. https://docs.mcneel.com/rhino/7/help/en-us/commands/multipipe.htm.
24. [24] SubD 2021. https://www.rhino3d.com/features/subd/.