--- ray/doc/notes/ReleaseNotes	2022/04/11 04:03:36	1.413
+++ ray/doc/notes/ReleaseNotes	2024/05/17 20:50:57	1.450
@@ -2542,3 +2542,156 @@ produce "-ld+" without requiring input picture as argu
 Added automatic overture calculation to rtpict with -n > 1 if
 ambient cache is on and file is named.  If straight image output
 is requested, we randomize all samples and avoid cache collisions.
+
+Added cnt -s option to shuffle output.
+
+Fixed issue with divide-by-zero errors in the ambient super-sampling
+routine discovered by Jon Sargent of Solemma.  This affected regions
+that had zero radiance, such as black backgrounds or unlit areas
+with -av 0 0 0, when super-sampling was effectively disabled, causing
+some loss in accuracy of the results.
+
+Updated Klems Half- and Quarter-bases to match angles currently used
+in WINDOW.
+
+Eliminated most aiming failures for triangular light sources, at the
+expense of conservative sampling near the centroid.  Thanks to
+David Geisler-Moroder for his help on this.
+
+Increased maximum set size to 8191 to avoid set overflow errors.
+
+Added source obstruction test to statistics being kept on which
+sources were visible in adaptive shadow testing code.  Previous
+behavior was likely over-estimating source contributions.
+
+Added diffuse components into maximum directional hemispherical
+reported by checkBSDF, so comparing to 100% is easier for each
+component.
+
+Fixed incorrect calculations in iso2klems script, thanks to
+help from Jacob Jonnson.
+
+Updated official copyright and license according to new wording
+provided by Jean Haemmerle at the LBNL Intellectual Property Office.
+Both were copied verbatim from e-mail I received from Taoning Wang
+on 8/20/2022.
+
+Added -features option to rpict, rtrace, and rcontrib to check
+which features are present or look for specific feature support.
+This addition was suggested by Peter Apian-Bennewitz as an easier
+way to determine which version of Radiance is installed and what
+it supports, and is timely as we begin our refactoring of the
+rendering code.  There are no current plans to add this to rvu.
+
+Added falsecolor -odim, -orct, and -c0 options to overlay grid of
+values on image.  This was requested by Rob Shakespeare.
+
+Added -i* and -o* options in rhcopy for reading rays from the
+standard input and writing rays from holodeck to standard output.
+This will hopefully be useful in combining rholo with rcontrib.
+
+Added further checking for coincident (overlapping) flat surfaces,
+preferring front sides to back sides in the ray intersection
+calculation.  This only applies to rings and faces, as the other
+surface types would have required additional calculations to
+make them work.  Material transparency is still the primary
+consideration, now followed by ray hit side, followed by
+modifier definition order in the input.
+
+Increased octree and object limits to allow scenes with billions
+of primitives.
+
+Made reciprocity averaging default to "off" in bsdf2ttree, as it seems
+to create more problems than it solves.
+
+====================
+Version 6.0
+
+Extensive changes to enable spectral rendering, which defaults to "off"
+to maintain backwards-compatibility with previous versions, with the
+exception of the ambient file format, which is changed.  The MAXCSAMP
+macro, which defaults to 24, sets the maximum number of spectral samples.
+The actual number of samples is set by the "-cs" option, which defaults
+to 3 for rpict, rtrace, and rcontrib.  The latter two programs support
+straight spectral output, but rpict is initially restricted to
+tristimulus output pictures.  New pattern primitives "spectrum",
+"specfile", and "specfunc" have been added as a means to specify
+spectral reflectance, emittance, etc. to materials that still have
+only 3 color channels.  Those RGB channels will still affect the
+spectrum if used.  Unfortunately photon-mapping is currently broken when
+spectral sampling is enabled, but we will fix this as soon as possible.
+Calculation overhead appears to be approximately 10-15% for RGB
+renderings compared to version 5.4a.
+
+Added spectral rendering to rvu as well, and made -cs and -cw
+options standard across the rendering library.  I also brought
+mkillum, ranimove, rsensor, and mksource into the fold.  These
+tools were broken in the initial release.  (Hopefully, they are
+working now, but none have been tested as yet.)
+There was also an indexing bug in the spectral->RGB conversions
+that made reds into blues and vice versa, which has been fixed.
+
+Added i/o for spectral pictures to rmtxop, the first program that can
+ingest them.  (Only rtrace, rcontrib, and rfluxmtx can render them.)
+New symbolic rmtxop -c options, such as RGB, XYZ, S (for scotopic)
+and M (for melanopic) make color conversions simpler.  Alternatively,
+a reference matrix or picture may be given and the color space of
+that file will be used.  The -C option takes either a symbolic
+color space or reference file and is "sticky," so it applies to
+all subsequent input files that do not have their own -c right ahead
+of them.
+
+Added spectral picture support to rcrop and radcompare.
+
+Added new utility, rcomb, which is something like a combination
+of rmtxop and pcomb, it works with all the inputs and
+outputs that rmtxop handles, but allows for general expressions
+like those in pcomb for putting matrices together, working on
+an element at a time.  (No resizing of matrices or accessing
+neighboring elements, as permitted in pcomb.)  It saves memory
+over rmtxop by operating on a row at a time, so can handle
+input and output matrices with any number of rows.  It does
+provide for a single matrix-multiplication operation at the end,
+which only requires memory for that final matrix.
+
+Added support for filtering hyperspectral images to pfilt.
+
+Added support for 1- and 3-component float matrix i/o to
+pcomb to allow for better interoperability.
+
+Added support for -co+ option to rtpict, so it can directly
+produce hyperspectral images.
+
+Added new "specdata" and "specpict" primitives to support
+interpolated spectral data files and hyperspectral images
+as patterns.
+
+Added support for multispectal sampling in rsensor, which will
+put out as many color channels as specified in any -cs option
+(default is 3 for RGB).
+
+Added ability of mgf2rad to convert spectral data at least
+for light, glow, plastic, and metal primitive types.  Need
+to use new '-s' option to get new output.
+
+Added handling of spectral images to rcode2bmp script.
+
+Minor change to rcollate to allow explicit byte records to
+be any specified length without checks against header input.
+
+Added new hemisphere type to rfluxmtx, "h=cie" for CIE sky
+scanner positions.  These are 145 patches with identical
+row counts to Tregenza, but starting from a different
+azimuth and reversing row directions at adjacent altitudes.
+
+Added optimization for long argument lists and arrays in
+the calcomp routines used for rendering and in rcalc, etc.
+
+Added error estimate spreading to ambient super-sampling
+algorithm (-as) to improve performance especially in
+scenes with sharp cut-offs.
+
+Added -i option to gendaymtx to match -i option of gendaylit.
+Thanks to Yongqing for initial implementation.
+
+Changed rcrop so negative #rows or #cols counts back from end.