[Radiance-general] IES2Rad questions

[Zack Rogers]

Thanks for your response Thomas.  I still think IES2rad is reading files differently than the standard (clockwise and with 0 as +y).  

I did figure out the Type B photometry issue, seems this is only a problem within Rayfront.  Using IES2rad outside of Rayfront does not have a problem, my apologies.  Everything else shown was also done outside of Rayfront as I was wanting to eliminate this from the equation.

Regards,
Zack

Zack Rogers, P.E., IESNA, LEED AP
Daylighting Analysis Group Leader
Architectural Energy Corporation
2540 Frontier Avenue, Suite 201
Boulder, CO 80301 USA
 
tel (303)444-4149 ext. 435
fax (303)444-4304
http://www.archenergy.com
 

-----Original Message-----
From: Thomas Bleicher [mailto:tbleicher at arcor.de] 
Sent: Tuesday, September 25, 2007 2:56 PM
To: Radiance general discussion
Subject: Re: [Radiance-general] IES2Rad questions

Hi Zack.

I haven't looked at IES files in a while so my memory is a bit mushy
and I can't go into the details of the standard as I don't have a copy.

But:

On 22 Sep 2007, at 04:39, Zack Rogers wrote:

> [...] However, to get the rendering shown above I had to have my  
> replmarks
> marker with +y up which seems to disagree with the header of the  
> source.cal
> file.  I also have to define the longer dimension as x and the  
> shorter dimension
> as y, similarly in disagreement with the source.cal file header.  
> When I try
> rendering it with +x as up I get a strange and obviously incorrect  
> rendering.
> Is this a bug or am I mis-interpreting this?

I think it's ies2rad that creates the confusion here. In the man page  
it says:

"The light source geometry will  always  be centered  at  the  origin  
aimed
in the negative z direction, with the 0 degree plane along the x axis."

This is fine for luminaires as they usually have their highest output in
negative z direction ('down') but define this in the IES file as 0  
degree
vertical angle (the vertical angles start pointing down and then go up).
In your case ies2rad might simply have turned the z-axis around so  
that your
+z is now pointing down.

If you use replmarks to place your windows you have to define the longer
axis as x and the sorter will be y. This is just how replmarks works and
is independent of source.cal.

I used to check the Radiance renderings of luminaire files against a  
rendering
of another application like Dialux or Relux just to check if I did  
the placement
and rotation of the IES file right.

Regards,
Thomas




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