Skip to main content
×
×
Home

Shape computations with NURB curves

  • Elif Ensari (a1) and Mine Özkar (a1)
Abstract

Freeform curves are commonly used in contemporary design practices, especially with digital modeling tools. We investigate facilitating shape subtraction and addition with two-dimensional (planar) non-uniform rational basis-spline (NURB) curves with the codes and conventions of modeling while preserving the visual continuity of curved shapes. Our proposed tool, developed in a common digital modeling environment, automates the adjustment of parameters for tangential continuity of curves in shape rule applications. When the user designates a curve range to subtract from an initial shape and provides a new curved shape to add to it, the tool splits the initial shape, scales and aligns the curve to be added to fit into this range, introduces additional control points at the joining ends of the new curve to preserve continuity and redraws the new curve. We present a sample set of design variations produced using this practical approach which can be utilized as a method or become part of an automated NURB curve manipulation tool for designers.

Copyright
Corresponding author
Author for correspondence: Elif Ensari, E-mail: elif.ensari@gmail.com
References
Hide All
Chau, HH (2002) Preserving brand identity in engineering design using a grammatical approach (Doctoral dissertation). University of Leeds, Leeds, United Kingdom.
Jowers, I and Earl, C (2009) The construction of curved shapes. Environment and Planning B: Planning and Design 37, 4258.
Jowers, I and Earl, C (2011) Implementation of curved shape grammars. Environment and Planning B: Planning and Design 38, 616635.
Jowers, I and Earl, C (2015) Extending the algebras of design. Nexus Network Journal 17(3).
Jowers, I, Hogg, DC, McKay, A, Chau, HH and de Pennington, A (2010) Shape detection with vision: implementing shape grammars in conceptual design. Research in Engineering Design 21, 235247.
Jowers, I, Prats, M, Earl, C and Garner, S (2004) On curves and computation with shapes. In Akin, O, Krishnamurti, R and Lam, KP (eds). Generative CAD Systems Symposium: G-CADS 2004. Pittsburgh: Carnegie Mellon University, pp. 439457.
Keles, HY, Özkar, M and Tari, S (2012) Weighted shapes for embedding perceived wholes. Environment and Planning B: Planning and Design 39, 360375.
Krishnamurti, R (1992) The maximal representation of a shape. Environment and Planning B: Planning and Design 19, 267288.
McCormack, JP and Cagan, J (2003). Increasing the scope of implemented shape grammars: a shape grammar interpreter for curved shapes. In Proc. ASME 2003 Int. Design Engineering Technical Conf. & Computers and Information in Engineering Conf., Paper No. DETC2003/DTM-48643, Chicago, IL, September 2–6.
McCormack, JP and Cagan, J (2006) Curve-based shape matching: supporting designers’ hierarchies through parametric shape recognition of arbitrary geometry. Environment and Planning B: Planning and Design 33, 523540.
Piegl, L and Tiller, W (1997) The NURBS Book, 2nd edn. New York: Springer-Verleg.
Stiny, G (2006) Shape: Talking About Seeing and Doing. Cambridge, Massachusetts: MIT Press.
Recommend this journal

Email your librarian or administrator to recommend adding this journal to your organisation's collection.

AI EDAM
  • ISSN: 0890-0604
  • EISSN: 1469-1760
  • URL: /core/journals/ai-edam
Please enter your name
Please enter a valid email address
Who would you like to send this to? *
×

Keywords

Metrics

Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed