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The plastic material with the rough diffusing surface can be modeled in &W:R#/|
TracePro, but as two separate properties (select Define/EditPropertyData). v#o<.
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MATERIAL PROPERTY eE- c40Bae
A TracePro Material Property can be created, and the index of refraction of M}*#{UV2
the material is entered here, as well as an absorption coefficient if it is /ng +IC3
known (this would be for absorption losses just from propogating through a _Vf0MU;3f+
given thickness of a clear polished sample of the material, unrelated to the ~ f:jI1(}
diffusing surface finish. Entering zero for the absorption coefficient is Vs~!\<?
propobly a reasonable estimate for a transparent material. GUqhm$6a
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The Material Property is applied to the Object (Define/Apply Properties). *>f-UNV
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SURFACE PROPERTY gBCO>nJws
A TracePro Surface Property can specify 5 possible outcomes for light incident + ZxG<1&
on a surface - Specular Transmission, Specular Reflection, Scattered {9yW8&m
Transmission (BTDF). Scattered Reflection (BRDF), and Absorption. !mLD` 62.
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For your property, I expect that Specular Transmission, Specular Reflection, X`E3lgfqT
and Absorption would all be 0, leaving only Scattered Transmission (BTDF). WG?;Z
Scattered Reflection (BRDF). BTDF and BRDF are controlled by 3 coefficients - \"^ .>+
A, B, and g. For an initial estimate, I would suggest entering BTDF(g) = T($6L7 j9
BRDF(g) = 0, which defines a Lambertian dsitribution. L4C_qb k;:
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The challenge is to determine the proper ratio of Transmittance vs sHi *\
Reflectance. You can enter a value for BRDF(A) and then use the Solve For }xE}I< M
feature to solve for BTDF, and the editor will display the resulting 8>y!=+9_
Integrated BTDF and Integrated BRDF values. You want these to sum to 1, and 69>N xr~k
to have a ratio that matches the behavior of your surface. If the ratio of T =fZMute
vs R is dependent on the Incidence Angle, you can use the Add button in the u Y'77,G_J
property to add Incidence ANgles to the table, and then define the BTDF and 3(/J(8
BRDF separately for each incidence angle.
