[Radiance-general] Diffusive laminated material and fritting

[Jack de Valpine]

Hi Giovanni,

The glaze script supports an IGU with (2) glass layers only. As I 
understand from Greg who developed this for us originally, the math 
starts to get a lot more complicated with a 3rd glass layer. This does 
not mean that it cannot be done but it would need to be implemented. I 
guess there are a few things to understand with the glaze script. What 
you want to get out of Optics 5 is Radiance material exports NOT for the 
full IGU makeup but instead for each layer of the makeup. Then you can 
use the transmittance and reflectance data for the exported materials to 
build material definitions for 2 layer glazing makeups where a coating 
can be allocated to one surface and a frit to another (note you cannot 
have both frit and coating applied to the same surface because we do not 
know how to characterized that). Regarding the interlayer, I think what 
I would suggest is that (assuming a clear interlayer) is to make up the 
composite in Optics 5 (eg 2 glass materials with an interlayer) and then 
export this as a glass layer.

Regarding Ming-w, I am sorry that I am not really familiar with 
compiling or running Radiance in this way, so I do not really know why 
things might not be found. Note that glaze is a shell script like 
falsecolor for example, so if you have falsecolor then glaze "should" be 
available and work...

-Jack

PS: you could also take a look at my talk at the 2009(?) Radiance 
Workshop at Harvard, which talks a bit about glaze and some other tools.

-- 
# Jack de Valpine
# president
#
# visarc incorporated
# http://www.visarc.com
#
# channeling technology for superior design and construction


On 10/28/2010 9:44 AM, Giovanni Betti wrote:
> Thanks Jack,
>
> I have done some more reading on the mailing list and found a few useful
> posts describing opt2rad and glaze.
> Both seem really useful, although glaze seems likely the most
> interesting option because (if I understand correctly) allows for frit
> and angular dependencies in transmission/reflection.
>
> Unfortunately I am using radiance on windows using the Ming-w compiled
> version and I do not find the files in my bin or lib folder (but I find
> glaze2.cal). Is there a version of these available for windows?
>
> Also Glaze supports only two glass panes with an interlayer or can cope
> with three-ply build ups?
>
> Thanks again,
>
> G
>
>
> -----Original Message-----
> From: radiance-general-bounces at radiance-online.org
> [mailto:radiance-general-bounces at radiance-online.org] On Behalf Of Jack
> de Valpine
> Sent: 28 October 2010 14:10
> To: Radiance general discussion
> Subject: Re: [Radiance-general] Diffusive laminated material and
> fritting
>
> Hi Giovanni,
>
> I will give a short answer and then try to follow-up later with a longer
>
> explanation. Regarding the diffusing interlayer, as I recall Optics 5 is
>
> not really set up to deal with diffusing materials (unless this has
> changed recently). Regardless, any material definition exported to
> Radiance format will be in the form of three materials: a glass
> definition and a front and back side BRTDfunc. Note however that the
> BRTDfunc (unless this has been changed) is a very simplified material
> definition that is not set up to account for angular variation. There
> are a couple of options to convert Radiance output from Optics 5 to
> something more useful: A) optics2rad or B) glaze. These are both scripts
>
> that come with the standard Radiance distribution.
>
> I am not sure what to suggest for how to manage the diffuse component.
> This can probably be incorporated into a BRTDfunc definition. Regarding
> the fritting, I agree with your presumption that if you are any
> reasonable distance from the building then the individual makeup (lines,
>
> dots, whatever), will disappear in most cases. It is possible to build
> up frit glass definitions (based on percent coverage) using the glaze
> script.
>
> Regards,
>
> -Jack de Valpine
>