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The plastic material with the rough diffusing surface can be modeled in DaJ,( DJY
TracePro, but as two separate properties (select Define/EditPropertyData). 63J3NwFt
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MATERIAL PROPERTY h Ypj
A TracePro Material Property can be created, and the index of refraction of 0|J9Btbp
the material is entered here, as well as an absorption coefficient if it is /W`CqJk-*.
known (this would be for absorption losses just from propogating through a S>r}3,]S
given thickness of a clear polished sample of the material, unrelated to the cMF)2^w}
diffusing surface finish. Entering zero for the absorption coefficient is Nsq=1)
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propobly a reasonable estimate for a transparent material. uF1 4 ;
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The Material Property is applied to the Object (Define/Apply Properties). ""
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SURFACE PROPERTY he/rt#
A TracePro Surface Property can specify 5 possible outcomes for light incident .ahY 1CO
on a surface - Specular Transmission, Specular Reflection, Scattered pdER#7Tq
Transmission (BTDF). Scattered Reflection (BRDF), and Absorption. e$P^},0/
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For your property, I expect that Specular Transmission, Specular Reflection, f0Q! lMv
and Absorption would all be 0, leaving only Scattered Transmission (BTDF). 8t=O=l\
Scattered Reflection (BRDF). BTDF and BRDF are controlled by 3 coefficients - (gPB@hAv
A, B, and g. For an initial estimate, I would suggest entering BTDF(g) = qo 7<g*kf~
BRDF(g) = 0, which defines a Lambertian dsitribution. }yn%_KQ0
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The challenge is to determine the proper ratio of Transmittance vs 5._QI/d)'J
Reflectance. You can enter a value for BRDF(A) and then use the Solve For X@}7 # Vt
feature to solve for BTDF, and the editor will display the resulting rqiH!R
Integrated BTDF and Integrated BRDF values. You want these to sum to 1, and tmoCy0qWz
to have a ratio that matches the behavior of your surface. If the ratio of T SmD#hE[
vs R is dependent on the Incidence Angle, you can use the Add button in the TTl9 xs,nO
property to add Incidence ANgles to the table, and then define the BTDF and `7y3C \zyQ
BRDF separately for each incidence angle.
