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The plastic material with the rough diffusing surface can be modeled in 2<p@G#(
TracePro, but as two separate properties (select Define/EditPropertyData). 5M~nNm[xJU
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MATERIAL PROPERTY sQ^t8Y 9
A TracePro Material Property can be created, and the index of refraction of Jc}6kFgO6
the material is entered here, as well as an absorption coefficient if it is /{jt] 8/;7
known (this would be for absorption losses just from propogating through a ]];pWlo!
given thickness of a clear polished sample of the material, unrelated to the IbL'Z
diffusing surface finish. Entering zero for the absorption coefficient is Yb_HvP
propobly a reasonable estimate for a transparent material. h(~/JW[
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The Material Property is applied to the Object (Define/Apply Properties). 2
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SURFACE PROPERTY $F9w0kz:,*
A TracePro Surface Property can specify 5 possible outcomes for light incident BBGub?(dR
on a surface - Specular Transmission, Specular Reflection, Scattered iWC}\&i
Transmission (BTDF). Scattered Reflection (BRDF), and Absorption. j[FB*L1!D
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For your property, I expect that Specular Transmission, Specular Reflection, "\`Fu
and Absorption would all be 0, leaving only Scattered Transmission (BTDF). 1cMLl6Bp>
Scattered Reflection (BRDF). BTDF and BRDF are controlled by 3 coefficients - ai1;v@1
A, B, and g. For an initial estimate, I would suggest entering BTDF(g) = a#% *H
BRDF(g) = 0, which defines a Lambertian dsitribution. Scm45"wB+
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The challenge is to determine the proper ratio of Transmittance vs MN5}}@
Reflectance. You can enter a value for BRDF(A) and then use the Solve For K@xMPB8in
feature to solve for BTDF, and the editor will display the resulting xgj 'u m
Integrated BTDF and Integrated BRDF values. You want these to sum to 1, and Mp!1x x
to have a ratio that matches the behavior of your surface. If the ratio of T u 0sN[<
vs R is dependent on the Incidence Angle, you can use the Add button in the ~n ) |
property to add Incidence ANgles to the table, and then define the BTDF and He5 y;5
BRDF separately for each incidence angle.
