# ADAPTIVE CONSTRAINT AND 3D SKETCH-BASED DEFORMATION FOR INTERACTIVE FREE FORM SURFACE STYLING

### Li Han, Raffaele De Amicis, Giuseppe Conti

#### Abstract

This paper tries to answer to the increasing demand in the domain of conceptual design for more intuitive methods for creating and modifying free-form curves and surfaces. This is done by addressing the issue of physical-based shape control by free hand spline sketching instead of the tedious mathematical parameters adjustment. We present a novel approach capable of matching the designer’s requirements in terms of quality and accuracy of the produced model. The algorithm adopts a simple 3D sketching technique and a finite element deformation method to create free-form models. In the method proposed the user applies interactive sculpting to modify a surface in a predicable way. Our algorithm automatically extracts the key points from sketched target curve and adaptively distributes the external-force constraints which impose the force energy on the corresponding control vertexes along their normal. We have limited the influence of these constraints to a localized area by attaching an influence factor to each control vertex of the parent surface. The smoothing function introduced later further solves the transition interval and it provides for symmetry features. This proposed method is finally implemented in a 3D scene environment and the results show how the designers intuitively and exactly control the shape of the surface.

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#### Paper Citation

#### in Harvard Style

Han L., De Amicis R. and Conti G. (2006). **ADAPTIVE CONSTRAINT AND 3D SKETCH-BASED DEFORMATION FOR INTERACTIVE FREE FORM SURFACE STYLING** . In *Proceedings of the First International Conference on Computer Graphics Theory and Applications - Volume 1: GRAPP,* ISBN 972-8865-39-2, pages 392-399. DOI: 10.5220/0001352803920399

#### in Bibtex Style

@conference{grapp06,

author={Li Han and Raffaele De Amicis and Giuseppe Conti},

title={ADAPTIVE CONSTRAINT AND 3D SKETCH-BASED DEFORMATION FOR INTERACTIVE FREE FORM SURFACE STYLING},

booktitle={Proceedings of the First International Conference on Computer Graphics Theory and Applications - Volume 1: GRAPP,},

year={2006},

pages={392-399},

publisher={SciTePress},

organization={INSTICC},

doi={10.5220/0001352803920399},

isbn={972-8865-39-2},

}

#### in EndNote Style

TY - CONF

JO - Proceedings of the First International Conference on Computer Graphics Theory and Applications - Volume 1: GRAPP,

TI - ADAPTIVE CONSTRAINT AND 3D SKETCH-BASED DEFORMATION FOR INTERACTIVE FREE FORM SURFACE STYLING

SN - 972-8865-39-2

AU - Han L.

AU - De Amicis R.

AU - Conti G.

PY - 2006

SP - 392

EP - 399

DO - 10.5220/0001352803920399