We present an interface for quick and intuitive development of arbitrary, but physically correct, Bi-directional Reflectance Distribution Functions, or BRDFs. Our interface, referred to as BRDF-Shop, provides artists the ability to create a BRDF through positioning and manipulating highlights on a spherical canvas. We develop a novel mapping between painted highlights and specular lobes of an extended Ward BRDF model. The implementation of BRDF-Shop utilizes programmable graphics hardware to provide a real-time visualization of the material on a complex object in environment lighting.
One application of BRDF-Shop is to visualize and design materials for automobiles.
Special thanks to Ahkeith Salley for the model of the Toyota Celica
Figure 2: Brushes of BRDF-Shop
(a)
(b)
(c)
(d)
Illustration of the different brushes and their effect on the BRDF. On the left, a real-time rendering with environment lighting on a torus, and on the right, the spherical canvas with a single point light source approximation for the environment. (a) illustrates the creation of a new highlight with the Create Brush. (b) shows the Modify Brush, which adjusts the roughness of the highlight. (c) shows the Streaking Brush, which pulls a highlight in the direction of the brush. (d) shows the De-Intensify Brush adjusting the distribution of energy between multiple lobes.
Figure 3: Happy BRDF
BRDF-Shop will allow you to make any arbitrary BRDF, including a smiley face on the spherical canvas.
