All platforms
=============

      ==> ImageMagick keeps on changing their option syntax and delegates
	  file format.  You may have to tweak the calls to ImageMagick
	  utilities in the stereo3d and label3d scripts to match your local
	  version of ImageMagick.

      ==> Stereo pairs can be generated by using either a shear operation or
      	  by using an angular offset.  Both have problems.  The shear distorts
	  bounding surfaces.  The angular offset displaces specular highlights
	  and totally breaks Z-clipping.

	- ISOLATE (object code 15) not yet implemented for quadric surfaces
	- Linear depth-cueing code (FOG 0) is not correct for parts of the 
	  scene behind a transparent object. This problem arises because a 
	  linear fog model does not correspond to reality. 
	  It would be possible to handle transparency correctly for an 
	  exponential fog model, but doesn't seem worth the effort right now.
	- Z-clipped objects cast un-clipped shadows.
	- The mixed Fortran/C calls to local() generate an interesting 
	  variety of compiler warnings because of inadequte type-casting
	  on the Fortran side.  
	- General quadric surfaces (other than ellipsoids) may cast spurious
	  shadows, and always fail to shadow themselves.
	- Explicit vertex colors take precedence over material colors;
	  (That's a feature, not a bug)
	- Labels with TeX-like escape sequences are always treated as Left-Align.
	- Angstrom symbol only loaded into Times/Helvetica fonts.
	- ribbon coloring scheme 6 doesn't work

SGI
===
	- In general the JPEG and PNG libraries supplied with Irix are bad,
	  and should be rebuilt from current source
	- Some versions of Irix contain a header file jpeglib.h that is not
	  compatible with the actual libjpeg in the same distribution
	- The PNG library and header files are from an ancient beta-test version.
	  You must choose between disabling PNG support in Makefile.template or
	  installing a newer version of libpng on your machine

AIX 
===
	File indirection in render doesn't work, because opening Fortran
	LUN 6 clobbers C I/O in local.c
	Work-around : 
		Patch file render_patch.aix modifies render to use
		LUNs 5,4,3,2,1 for file indirection rather than 6,7,...
	dispose='delete' not permitted in open statement
	Work-around :
		None; temp files accumulate until deleted

linux (g77 and gfortran compilers)
====================

	The g77 and gfortran compilers do not support file open options 
	CARRIAGECONTROL='LIST' or DISPOSE='DELETE'.
	Work-around :
		'make linux' deletes these specifications from the source
		files; unfortunately, this means that temporary files do not
		automatically get deleted from the system temp directory.