[Radiance-general] two sided surface

[Greg Ward]

Hi Nick,

Unfortunately, you've hit upon the one case that Radiance doesn't  
really handle properly:  curved, specular window coverings.  Your best  
hope at this point is to add some roughness to the specular side of  
your surface and use mkillum to generate an output distribution.  If  
you could measure a BTDF for the blinds and give it to mkillum that  
way, you'd be golden, but I don't expect that you have such a thing.

Eventually, we hope to create a tool that would allow you to model  
this (and other types) complex fenestration, but we're a few months  
away from having that ready.

Cheers,
-Greg

> From: "Nick Hubof" <nhubof at gmail.com>
> Date: April 30, 2010 8:11:36 AM PDT
>
> I have modeled the reflective blinds that we had discussed in this  
> thread earlier, but I would like your opinion on the rendering  
> settings. I could do a bunch of tests at low resolution but even  
> with our 8 processor mac it still takes a while and I would get  
> faster results asking all of you smart people out there.
>
> Here is an image of the blinds in an open position.
>
> http://i23.photobucket.com/albums/b354/mrhubof/General/genzyme_2010_04_21_c1.jpg
>
>
>
> The resulting image has many reflection spots on the ceiling, which  
> is the problem.  The ceiling is mostly just a white material. The  
> floor is a carpet.
>
>
>
> render=  -ab 8 -aa 0.08 -ar 2094 -ad 1024 -as 512
>
> 840x480 – rendering took 7 hours
>
> Scene size = 33
>
> Sunny, Sep at noon in New York, windows face south.
>
>
>
> The top of the blind (concave facing ceiling) is:
>
> void metal concave
>
> 0
>
> 0
>
> 5 0.9 0.88 0.88 0.8 0.02
>
>
>
> Thank you much,
>
> Nick