Download lib3ds-20080909.zip.
Extract the archive, then rename the created lib3ds-20080909 directory to
lib3ds-20080909-x86.
Extract the archive again, then rename the lib3ds-20080909 directory to
lib3ds-20080909-x64.
Extract the archive again, then rename the lib3ds-20080909 directory to
lib3ds-20080909-ppc.
Go into the lib3ds-20080909 directory, then run ./configure.
Edit src/Makefile.
Add " -arch i386" (without the quotes) to the end of the CFLAGS = line.
Do the same thing to the CXXFLAGS = line.
Do the same thing to the LDFLAGS = line.
Save the Makefile, then run make.  Ignore the link errors at the end that are a
result of the test apps not having the same architecture as the library.
Repeat in the lib3ds-20080909-x64 directory, but use "-arch x86_64".
Repeat in the lib3ds-20080909-ppc directory, but use "-arch ppc".
Go back into the directory above all three lib3ds-20080909 directories and run
the following command:
libtool -o lib3dsu.a lib3ds-20080909-???/src/.libs/lib3ds.a
Use sudo to copy lib3dsu.a into /usr/local/lib/.
