RADIANCE Compile Switches

Here is a list of compile switches, used to customize Radiance code for specific machines and users:
-DALIGN=(type)
Alignment type, machine-dependent. Most RISC architectures align on 8-word boundaries (double). The default alignment type is int.
-DSPEED=(MIPS)
Millions of instructions per second for this processor (approximate). This is used to decide certain unimportant timing issues such as how many rays to trace before checking input in rview and whether or not to optimize the color table in ximage on 8-bit displays.
-DWFLUSH=(rays)
Override for number of rays before flush in rview.
-DBSD
Operating system has a strong Berkeley flavor, meaning that bcopy() and bzero() are present but maybe memcpy() and memset() are not. (See common/standard.h for other things this flag affects.) Also affects certain system calls, such as signal handling and resource tracking.
-DSMLMEM
The system has little RAM available, so size hash tables and the like accordingly. Only allows for small scene descriptions (32,256 primitives).
-DSMLFLT
This setting tells Radiance to use short floats (4-bytes) throughout, which saves lots of memory but can cause calculation inaccuracies in many cases. Its use has been discontinued for this reason.
-DSHADCACHE=N
The array size to use for caching occluders. Setting this to 0 turns off this optimization. Values greater than 20 use over 4 Kbytes per light source, which can add up to a lot of memory in scenes with many sources.
-DAVGREFL=R
Set the average surface reflectance for the purpose of indirect irradiance calculations to R, where R is a real number in the range (0,1.0). The default value is 0.50 (50%).
Other defines may be used to overcome portability problems on various operating systems.