message: Clarify the attenuation term in the clear coat model
diff: @@ -714,10 +714,10 @@ This correspond to a Fresnel reflectance of 4% that we know is associated with c
  Because we must take into account the loss of energy caused by the addition of the clear coat layer, we can reformulate the BRDF from equation $\ref{brdf}$ thusly:
  $$\begin{equation}
  -f(v,l)=(\fDiffuse(n,l) + \fSpecular(n,l))(1 - F_c) + f_c(n,l)
  +f(v,l)=(\fDiffuse(n,l) + \fSpecular(n,l))(1 - F_c)^2 + f_c(n,l)
  \end{equation}$$
  -Where $F_c$ is the Fresnel term of the clear coat BRDF and $f_c$ the clear coat BRDF.
  +Where $F_c$ is the Fresnel term of the clear coat BRDF and $f_c$ the clear coat BRDF. The multiplication by $(1 - F_c)^2$ is to remain energy conservative as the light enters and exists the clear coat layer.
  ### Clear coat parameterization
  