"And" <49341109@ntnu.edu.tw> wrote:
>
> I derived a solution on what I said the albedo value getting dark when sigma
> increase.
> I study the formula from the wikipedia. It said A=1-0.5*..., B=0.45*...(Both
> rely on the sigma)
>
> And the result albedo seems rho*A + rho*B*(2/3-64/45/pi) instead rho
> itself. So maybe you can divide it when apply the diffuse albedo feature.

Should say:

For a small area 'da', incident light irradiance 'E0', and if the incident angle
'theta_i' is fixed, it will receive E0*da*cos(theta_i) energy per second. then
emit
rho*E0*da*cos(theta_i)*A
+rho*E0*da*B/pi*(
                 sin(2*theta_i)*(theta_i/2 - sin(2*theta_i)/4)
                +2*sin(theta_i)*(1/3 - pow(sin(theta_i),3)/3)
)
energy per second.


Then I apply a condition that a homogeneous hemisphere lighting, equivalent to a
fixed incident radiance 'Li', then the small area 'da' receives Li*pi*da energy
per second, emit rho*Li*pi*da*A + rho*Li*da*B*(2*pi/3-64/45) energy per second.
So get the actual albedo rho*A + rho*B*(2/3-64/45/pi).

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