Artifice, Inc. and the Design Integration Laboratory

Radiance Hints and Tips


An Informal Collection of Miscellaneous Radiance Tips

... in order of random occurrence ...

by Kevin Matthews, Design Integration Laboratory

Note: You can search this page for specific terms using the Netscape Edit menu Find command.


Working with Lights

- Use objects with as few faces as possible for your light sources.  

  A tetrahedron light source, with four faces, will render about 33%
  faster than a cube light source with 6 faces.

- Use as few light source objects as will produce the desired effect.

- Renderings increase in time roughly linearly with the total number
  of light source surfaces.
  
- For qualitative lighting simulations, only worry about relative brightness
  of light sources, and use radiance exposure functions to set the desired 
  brightness for the finished image.  For example, to produce a night time
  dimness for an exterior rendering, something like:
  
  ra_pict -e -3 project_1.pic project_1.pict
  
  would be a good first guess for an exposure correction.  


Tuning Power MachTen

Tenon Intersystems says some things about Power MachTen system tuning:

1)  You should definitely increase your "Disk Cache" at the Memory control panel
to 512K or a little more.  

2)  Using virtual memory will slow things down, but it will let you render bigger
scenes.  You can run Mac OS virtual memory with MachTen, for up to 50% more total
memory than you have physical memory.  

3)  You should keep free space on your system disk equivalent to (or greater
than) your total amount of virtual memory.    


Which Color Picker?  

The color picker you've seen me use in class, with a large color wheel on the
right, a color indicator block on the top left, HSB color numbers on the middle
left, and RGB color numbers on the lower left, and with its color numbers running
from 0 to 65535, is built in to the Macintosh computer.  

However, System 7.5 comes a different color picker, which is installed as a
system extension.  

To get rid of the newer, less-useful color picker, open your System Folder, and
pen the Extensions folder.  Locate the Color Picker extension, and remove it from
the Extensions folder.  Then restart your computer, and you should see the good
old standard color picker again.  


How to Render a Section-Perspective in Radiance

(I don't know whether I've actually done this or not, but I believe this will work.)

1)  Set up the section-perspective view you want in DesignWorkshop, probably a
one-point perspective, and then Set the view with a clear view name and Save 
the model for good practice.  

2)  Still in DW, use the File menu Export 3D > Radiance Scene... command to create the .rad
and .rif files for the scene.  

3) Still in DW, record the "zone of interest" in a special way, making sure that
your numbers are very accurate.   When you define the "zone box", by giving the
coordinates of two opposite corners of it, you are also defining a "clipping box"
that will be applied if the zone of interest type is "interior".  

Therefore, to get a section perspective, you want to define the zone box so that
the face of it closest to the eye point is exactly in the sectioning plane for
the section perspective.  

 4) Then use the .rif file, generated automatically by the DesignWorkshop 
Export Radiance Scene command, setting the special sectioning zone as 
defined in the previous step, and with a zone type of "interior".  

5) Render until done, with the usual command "nice rad project.rif &".  


Instructions for deleting an entire directory of files in a Unix system like
Darkwing (assuming there are no subdirectories) 

1) Go to into the directory itself, using the "cd" command, as in

    cd directory

2) Check to make sure you are where you think you are, and make sure you really
want to delete the contents of this directory, using the "ls" command.

    ls

3) Delete all the files in the directory, using the "rm" command together with
the wildcard character "*".  USE THIS COMMAND CAREFULLY.  

    rm *

4) Go up one level in the directory hierarchy, so you can see the directory name,
instead of being in the directory, with the "cd" command.

    cd ..

5) Check to make sure you are where you think you are, and make sure you really
want to delete this directory, using the "ls" command.

    ls

6) Delete the directory itself, using the "rmdir" command.    

    rmdir directory

7) Confirm that the directory isn't there anymore, using the "ls" command.

    ls

8) Done.  


Defining the RAYPATH Environment variable

The setup of user accounts for Radiance is incomplete on Darkwing and Gladstone. 
Not surprisingly, since they don't really have a mechanism for providing the
account customization required by special applications -- nor tracking of who
would need it.  

You need to add the following line of text to your .login file, in your home
directory.  (Use "ls -la" to see the "." files.):

     setenv RAYPATH .:${HOME}/mylib:/usr/local/lib/ray

This can be done directly in the Unix environment if you're familiar with "vi" or a
similar archaic terminal-based text editor.  Otherwise, you could Fetch your
.login file to a local machine, edit the file with something like BBEdit, making sure
that you save the file with Unix-type line breaks, and then you could Fetch the
.login file back to your home directory at Darkwing.  

For the changes in .login to be in effect, you need to log out and then log back
in to your Radiance account.  


Auckland Image-Mapping Notes


Auckland Image-Mapping Notes


"rmake" Build Script Options for Making Radiance on Power MachTen 

This is what needs to be set in the file: /usr/local/bin/rmake 
   to install the standard Radiance distribution on Power MachTen.
   
   It sets appropriate compiler options for the MachTen UNIX, and for the
   PowerPC processor, and adds code library paths to let the X11 libraries
   be linked in, if they're installed in MachTen according to Tenon's instructions.

#!/bin/sh
exec make "SPECIAL=" \
	"OPT=-O" \
	"MACH= -DBSD -DALIGN=double -DBIGMEM -DDCL_ATOF -I/usr/X11/include -L/usr/X11" \
	ARCH=12 "COMPAT=bmalloc.o erf.o strcmp.o" \
	INSTDIR=/usr/local/bin \
	LIBDIR=/usr/local/lib/ray \
	CC=gcc "$@" -f Rmakefile
	



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