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The plastic material with the rough diffusing surface can be modeled in ?sf2h:\N
TracePro, but as two separate properties (select Define/EditPropertyData). <aSLm=
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MATERIAL PROPERTY -=[o{r`
A TracePro Material Property can be created, and the index of refraction of XJlDiBs9=Q
the material is entered here, as well as an absorption coefficient if it is [+MH[1Vr={
known (this would be for absorption losses just from propogating through a Z>Kcz^a#
given thickness of a clear polished sample of the material, unrelated to the {`F x~w;i
diffusing surface finish. Entering zero for the absorption coefficient is @t; O"q'|
propobly a reasonable estimate for a transparent material. ]i ,M q
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The Material Property is applied to the Object (Define/Apply Properties). "E ok;io
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SURFACE PROPERTY =Mu' +,dT
A TracePro Surface Property can specify 5 possible outcomes for light incident U8QR*"GmT
on a surface - Specular Transmission, Specular Reflection, Scattered RZ)vU'@kx
Transmission (BTDF). Scattered Reflection (BRDF), and Absorption. -4y)qGb*?
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For your property, I expect that Specular Transmission, Specular Reflection, <7FP" YU
and Absorption would all be 0, leaving only Scattered Transmission (BTDF). 0 bPJEEd
Scattered Reflection (BRDF). BTDF and BRDF are controlled by 3 coefficients - 0'%+X|
A, B, and g. For an initial estimate, I would suggest entering BTDF(g) = g"Q}h
BRDF(g) = 0, which defines a Lambertian dsitribution. ,LW(mdIe(
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The challenge is to determine the proper ratio of Transmittance vs *`g-gk
Reflectance. You can enter a value for BRDF(A) and then use the Solve For *<.WL"Qhl
feature to solve for BTDF, and the editor will display the resulting r>Qyc
Integrated BTDF and Integrated BRDF values. You want these to sum to 1, and d )hzi
to have a ratio that matches the behavior of your surface. If the ratio of T -@ UN]K
vs R is dependent on the Incidence Angle, you can use the Add button in the 9#s95R O
property to add Incidence ANgles to the table, and then define the BTDF and 3<jAp#bE
BRDF separately for each incidence angle.
