recommended method for simulating specular shades

[Rebecca Powles]

Is there a recommended method for simulating specular shades?

I have been asked to simulate some indoor roller shades which are made of a sheet of coated polymer - they are definitely specular materials.  I  have the solar integrated properties of these shades and as far as I know these particular products are not selective so I am happy to use the broadband properties for now, in line with how I would treat a fabric roller shade.  

I tried (in WINDOW 7.8.54 and 8.0.33) defining a shade material and unchecking the 'non-specular' checkbox, thinking that maybe this would indicate that the entered values are normal incidence specular properties rather than hemispherical.  No errors are raised, but if I use this material in a shade layer, add the shade to a glazing system and try to calculate, WINDOW crashes.  Is this approach supposed to work? 

I am sure that manually creating a specular-only XML BSDF file and using that will work fine, but before I try that I was wondering if there is a specific recommended method for this case and/or an easier modelling alternative that I have missed?

Rebecca

Rebecca Powles