Re: [Brad] Help:Setting up a radiance system--brad

[Thomas Bleicher]

Ok. I have looked at the code and tested the export function
on my system. brad does nothing to the geometry. It does not
matter what type the lamp data in Blender is (lamp, spot, etc)
as long as there is a file in your library that matches the
name of the lamp data object.

The process requires you to:

1) create the *.rad and *.dat file from the IES data file with
   ies2rad. Doing this you have to choose the right dimensions
   for the conversion.

   Based on your report I assume this has been done.

2) Move *.rad and *.dat files in a folder named like the IES file
   in the ../brad/radiance/lum/ directory

3) start Blender. In Blender there should now be a new entry in
   the luminaire library. Next to the big button with the name
   there is a small "+" button. Pressing this button creates a
   Blender lampdata object which is NOT attached to any lamp
   at the moment.

4) You have to select the lamp you want to export. In Blender's
   'Edit Buttons' window look at the menu button that defines
   the lampdata object (starts with 'LA:') if you press it you
   can see all the lampdata objects in the scene. One of those
   has the name of the IES file and a zero in front of it (it
   is not yet used by any lamp). Select this entry from the
   menu.

   This assigns the IES data to the lamp object via the
   name of the lampdata object. I don't think any of the
   lamp settings has an effect on the light distribution.

5) When you export the lamp brad creates a reference to the
   *.rad file and copies it in the export directory. It does
   not copy the *.dat file which results in an error. You
   have to do this manually.

   To verify: The file which contains the lamp locations has
   the extension '.lum'. Open it in a text editor it should
   contain lines starting with '!xform'. If there is any other
   content in the file that means the a lamp has been converted
   from Blender lampdata and the IES data is NOT used.

6) start rvu with the command "rad -o x11 <scene>.rif" where
   <scene> is the base name of your Blender .blend file. This
   command has to be executed in the export directory and all
   Radiance paths have to be set up correctly.

If everything went all right you should see your fitting (or
rather a glowing box the size of your fitting).


On 19 Apr 2007, at 05:40, steve michel wrote:

> When I did that with brad, the bi directional fixture did not even
> register on the ceiling..and as a spot is shows up as a circle and
> as an area lamp it is square!

This suggest that the IES data was not successfully associated with
the lamp. The lamp type will only make a difference when no library
luminaire is found for the lampdata object. Check that you have a
lampdata object with the name of your IES file and that it is used
by the lamp you want to export (step 4 above).


> Can anyone confirm this when placing different lamp geometry in brad?

Nope. brad works right (mostly) from my point of view. The procedure
requires some of knowledge of the Blender scene structure and the
data types but that's necessary for Blender anyway.


Hope this gets you a step further.

Thomas