I'm doing some quick daylight studies to get ASE and sDA and we are thinking about using a fritted glass:
If i use (VLT*1.09) to convert into radiance material, is this ok? Will my ASE / sDA outputs be flawed?
I know its not technically correct, but i don't want to take the trouble of using other software to create the exact radiance material when we are not sure what frit patter, frit %, or frit color we even need. So i thought i could do come quick conversions to get me close enough??
I've been away from the forum for a while, and I apologize that no one answered your question yet.
The total luminous transfer will be more or less correct by using VLT * 1.09, but if you want to test frits things do get more complex. The big issue is that your light propagation inside of a space will improve with a frit since more light is reaching the walls and ceilings versus the floor. Simple glass materials don't account for this.
I would suggest to use a trans material if your frit will be on the outside of the glass to try different direct / diffuse transmission values. Note that the angular transmissive properties of glass are lost when using the trans material.