lightshelf simulation

Dear all
I am analyzing light shelf with different dimensions for my thesis. I want
to compare a model with light shelf with a model without shelf. I wonder If
I should change the ambient bounces parameter in the no shelf model,
because the reflections decreases, or not,? The ab parameter that used for
the models with shelf is 3.
Thanks in advance
Sincerely
Shailan Zareiy

It could depend on your measurement point and the rest of the model. Does raising to a higher ab value for both models increase calculation time too much? Maybe you could increase to 5 or more bounces for both models and relax other parameters but maintain reliable results. If you repeat the simulation multiple times or increase calculation parameters and get results within a reasonable margin of error, then you're probably as accurate as possible for the model inputs.

···

From: shailan zareiy [mailto:[email protected]]
Sent: Monday, November 19, 2012 3:00 AM
To: Radiance general discussion
Subject: [Radiance-general] lightshelf simulation

Dear all
I am analyzing light shelf with different dimensions for my thesis. I want to compare a model with light shelf with a model without shelf. I wonder If I should change the ambient bounces parameter in the no shelf model, because the reflections decreases, or not,? The ab parameter that used for the models with shelf is 3.
Thanks in advance
Sincerely
Shailan Zareiy
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I think that it is important to understand that one really has to consider more than just ambient bounces (-ab). Certainly this is important, but ambient resolution (-ar) can have a significant impact on results followed by the other ambient related parameters (-ad, -as, -av).

I note that in an earlier post of yours regarding "reflector size" you show parameters with -ar 32. Although I have no idea of the size of your space, this seems low to me.

I think if you are doing a design comparison and looking at performance, you need change as few variables as possible between design scenarios. Ideally, in this case, the only "variable" that should change between simulation runs is light shelf or no light shelf. That way your comparison is not undermined by questions of other varying parameter settings.

-Jack

···

--
Jack de Valpine
President

Visarc Incorporated

channeling technology for superior design and construction

On 11/19/2012 9:16 AM, Christopher Rush wrote:

It could depend on your measurement point and the rest of the model. Does raising to a higher ab value for both models increase calculation time too much? Maybe you could increase to 5 or more bounces for both models and relax other parameters but maintain reliable results. If you repeat the simulation multiple times or increase calculation parameters and get results within a reasonable margin of error, then you're probably as accurate as possible for the model inputs.

*From:*shailan zareiy [mailto:[email protected]]
*Sent:* Monday, November 19, 2012 3:00 AM
*To:* Radiance general discussion
*Subject:* [Radiance-general] lightshelf simulation

Dear all

I am analyzing light shelf with different dimensions for my thesis. I want to compare a model with light shelf with a model without shelf. I wonder If I should change the ambient bounces parameter in the no shelf model, because the reflections decreases, or not,? The ab parameter that used for the models with shelf is 3.

Thanks in advance

Sincerely

Shailan Zareiy

____________________________________________________________
Electronic mail messages entering and leaving Arup business
systems are scanned for acceptability of content and viruses

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