[Radiance-general] setting RAYPATH (was: Upgrading to R4: "There were some errors.")

[Lars O. Grobe]

Hi!

Cramer Silkworth wrote:
> echo $RAYPATH currently yields nothing, so maybe that's the problem 
> (but PATH does include usr/local/bin). My problem is, i'm not really a 
> linux guy, and googling how to set it returns no fewer than a 
> gazillion different places that PATHs are set. Can you tell me where 
> the best place would be, and what exactly the line is (in Ubuntu 
> 9.10)? Sorry, I know it's a newbie question, but there doesn't seem to 
> consensus on the internet (not that there ever really is) on how to do 
> this.
This is required ONLY for those not using an installer or package 
manager. Typically these are developers or advanced Radiance users who 
do not need this advice. I however add this to complete the thread on 
installing Radiance.

The RAYPATH variable contains directories that are searched by Radiance 
at runtime for all scene-related files. This can be geometry, octrees, 
procedural cal-files, textures,... It is NOT used to search for binaries 
- the system's standard PATH variable is used for that.

1) To do anything useful with Radiance, one should have the directory 
containing the cal-files coming with Radiance included in RAYPATH. This 
is the lib-directory in the installation target - the default makeall 
script would probably use /usr/local/ray/lib (you are asked for the 
library location when running makeall). So this is the first.

2) Many of us will maintain their own library for textures, cal-files, 
octrees to be used as instances. This one should be the second directory 
included, say, /usr/share/radiance/objlib

3) There may be a directory containing a similar library, but only for 
use with one project. This may be a subdirectory of the project, say, 
/home/cramer/project/theater1/lib

4) Many of us like to have the current directory in their RAYPATH as a 
default. May lead to messing up the system, but is comfortable while 
developing e.g. a cal-file that is not ready to go into the library yet.

So - the RAYPATH should always include 1, 2, and 4, but 3 on a 
per-project base. If you are using the Bash as a shell (probably you do 
on Linux), add the RAYPATH to your Bash-configuration in your home 
directory:
--
cd
gedit ,bashrc
--
(if you do not want the Gnome-GUI use nano instead of gedit) and add the 
following line to the end
--
export RAYPATH=$RAYPATH:/usr/local/ray/lib:/usr/share/radiance/objlib:.
--
This APPENDS the directories to the RAYPATH instead of overwriting it.

For point 3, you can just include it before starting a simulation by typing
--
export RAYPATH=$RAYPATH:/home/cramer/project/theater1/lib
--
at the command line before starting a simulation, or you add it to the 
beginning of a small script that you may use for calling the necessary 
commands for your simulation.

I hope this helps. It should at least explain why you found many 
different RAYPATH-setting in the archives - it really depends on where 
people keep their stuff.

Cheers,

Lars.