# AN INCREMENTAL WEIGHTED LEAST SQUARES APPROACH TO SURFACE LIGHTS FIELDS

### Greg Coombe, Anselmo Lastra

#### Abstract

An Image-Based Rendering (IBR) approach to appearance modelling enables the capture of a wide variety of real physical surfaces with complex reflectance behaviour. The challenges with this approach are handling the large amount of data, rendering the data efficiently, and previewing the model as it is being constructed. In this paper, we introduce the Incremental Weighted Least Squares approach to the representation and rendering of spatially and directionally varying illumination. Each surface patch consists of a set of Weighted Least Squares (WLS) node centers, which are low-degree polynomial representations of the anisotropic exitant radiance. During rendering, the representations are combined in a non-linear fashion to generate a full reconstruction of the exitant radiance. The rendering algorithm is fast, efficient, and implemented entirely on the GPU. The construction algorithm is incremental, which means that images are processed as they arrive instead of in the traditional batch fashion. This human-in-the-loop process enables the user to preview the model as it is being constructed and to adapt to over-sampling and under-sampling of the surface appearance.

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#### Paper Citation

#### in Harvard Style

Coombe G. and Lastra A. (2006). **AN INCREMENTAL WEIGHTED LEAST SQUARES APPROACH TO SURFACE LIGHTS FIELDS** . In *Proceedings of the First International Conference on Computer Graphics Theory and Applications - Volume 1: GRAPP,* ISBN 972-8865-39-2, pages 84-91. DOI: 10.5220/0001358700840091

#### in Bibtex Style

@conference{grapp06,

author={Greg Coombe and Anselmo Lastra},

title={AN INCREMENTAL WEIGHTED LEAST SQUARES APPROACH TO SURFACE LIGHTS FIELDS},

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

year={2006},

pages={84-91},

publisher={SciTePress},

organization={INSTICC},

doi={10.5220/0001358700840091},

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 - AN INCREMENTAL WEIGHTED LEAST SQUARES APPROACH TO SURFACE LIGHTS FIELDS

SN - 972-8865-39-2

AU - Coombe G.

AU - Lastra A.

PY - 2006

SP - 84

EP - 91

DO - 10.5220/0001358700840091