I'am studying PBR and the book introduce the potential equation.They said the potential equation can describe shooting algorithms better, and$W(x, \theta)$ describes the fraction of the radiance $L(x, \theta)$But I could not understand the concept. Is just $W(x, \theta)$ a fraction such as $\frac{1}{3}$(I know the original equation is quite complicate, integral) to reduce the radiance $L$ which is derived from a light source? (because the L would be diminished if it collides with objects).
What is the potential equation in PBR?
physically based;pbr;photo realistic;realistic