Radiance Values for Translucent blinds


#1

Hi,

Im inputting a material for a translucent blind that diffuses the light. And require information on what would be the best material setup in radiance. i thought it would be best to use a trans material but i dont know what typical specularity, roughness, transmisivity or transmittedSpecular values would be. As seen in the attached image I require all the values.Does anyone know the values that can be used in this case to represent a translucent blind?

In this case the red, blue and green transmittance is 0.05


#2

Do you have any specific product in mind? Some products are tested to EN standards with published values for both Tv n-n (normal-normal, e.g. specular transmission) and also Tv n-h (normal-hemispherical e.g. total direct+diffuse transmission). And if the product has this amount of information it should also have visible or solar reflectance value which would probably be mostly diffuse. You could make some reasonable guesses and plug it into a calculation similar to the tool at http://gaia.lbl.gov/people/andy/public/transwidget/ to get the 7 values including transmission, transmissivity, and specular fraction.

Hint: the first three values are not simply the red green and blue transmission, but color values impacted also by how much reflectance your material has.