Paper Info
Title
Time-varying BRDFs.
Abstract
The properties of virtually all real-world materials change with time, causing their bidirectional reflectance distribution functions (BRDFs) to be time varying. However, none of the existing BRDF models and databases take time variation into consideration; they represent the appearance of a material at a single time instance. In this paper, we address the acquisition, analysis, modeling, and rendering of a wide range of time-varying BRDFs (TVBRDFs). We have developed an acquisition system that is capable of sampling a material's BRDF at multiple time instances, with each time sample acquired within 36 sec. We have used this acquisition system to measure the BRDFs of a wide range of time-varying phenomena, which include the drying of various types of paints (watercolor, spray, and oil), the drying of wet rough surfaces (cement, plaster, and fabrics), the accumulation of dusts (household and joint compound) on surfaces, and the melting of materials (chocolate). Analytic BRDF functions are fit to these measurements and the model parameters' variations with time are analyzed. Each category exhibits interesting and sometimes nonintuitive parameter trends. These parameter trends are then used to develop analytic TVBRDF models. The analytic TVBRDF models enable us to apply effects such as paint drying and dust accumulation to arbitrary surfaces and novel materials.
Year
DOI
Venue
2007
10.1109/TVCG.2007.1013
IEEE Trans. Vis. Comput. Graph.
Keywords
Field
DocType
measure- ment,time-varying phenomena,index terms— brdfs,natural phenomena.
Bidirectional reflectance distribution function,Computer graphics (images),Computer science,Joint compound,Sampling (statistics),Rendering (computer graphics)
Journal
Volume
Issue
ISSN
13
3
1077-2626
ISBN
Citations 
PageRank 
3-905673-38-X
9
0.56
References 
Authors
20
5
Name
Order
Citations
PageRank
Bo Sun124816.16
Kalyan Sunkavalli250031.75
Ravi Ramamoorthi34481237.21
Peter N. Belhumeur4122421001.27
Shree K. Nayar5123941538.46