--- ray/doc/notes/ReleaseNotes	2003/07/10 03:47:00	1.8
+++ ray/doc/notes/ReleaseNotes	2018/10/09 17:57:17	1.327
@@ -1140,7 +1140,7 @@ of recursive routines using sets to avoid overrunning
 the stack limit.
 
 ==============================
-Version 3.6
+Version 3.6 (Released 10/21/04)
 
 Modified 4-byte RGBE encoding routine to avoid problems
 when one or two primary values is negative and the other(s)
@@ -1172,4 +1172,1069 @@ Added -N option to rad to start multiple rendering pro
 parallel.
 
 Fixed bug where mesh instances were not being freed, so subsequent calls
-in programs like ranimate would refer to bogus data.
+in programs like ranimove would refer to bogus data.
+
+Added support in normtiff for floating-point and 16-bit/sample TIFF input
+files.
+
+Changed marksources() routine (src/rt/source.c) to check all
+primitives in the modifier chain for emitting types, not only
+the first.  This permits sources to be described with intervening
+modifiers before the light/illum/glow primitive and allows aliases
+as well.
+
+Fixed bug in xform where it was neglecting to add transform arguments
+to new mesh primitive.
+
+Added -dF and -dD options to pvalue for byte-swapped floats and
+doubles, respectively.
+
+Changed meta2tga to output correct colors.
+
+Changed local coordinate index from 32-bits to 16-bits, which requires
+that Radiance mesh files be recompiled.  (Later decided against this
+change, as it caused problems with some models.)
+
+Changed integer tone-mapping routines to better deal with images
+containing large, constant regions.
+
+Improved interaction with rholo -o ogl driver under OS X, which was
+returning bad values from the depth buffer.
+
+Minor bug fix in ranimove where it was restarting processes when it
+didn't need to.
+
+Increased accuracy of default ambient parameters in rpict, rview, and
+rtrace.  In rad program, doubled -ar value, -ad value, and -as value,
+and decreased -aa value a bit.  Also adjusted -lr upwards and -lw
+downwards.  I should have done these things long ago, as processors
+have been getting faster and faster over the years.
+
+Fixed bug discovered by Marcus Jacobs where oconv was dumping core
+when it was given too many modifiers.
+
+Fixed problem with rpict where it was drawing illum sources badly
+even when they weren't all that small in the view.
+
+Added in(i) function to rcalc for more flexible channel evaluation.
+
+Replaced all calls to vfork() with regular fork() calls.
+
+Fixed bug in glarendx for dgr calculation with sources behind view.
+
+Added -p option to histo to print percentages/percentiles r.t. counts.
+
+Added a source occluder cache to accelerate shadow testing.  This
+can save up to 50% of the calculation time in scenes with many
+light sources, especially ones containing large occluders.  This
+optimization may be tuned or switched off with the -DSHADCACHE=N
+compile switch, where N is the resolution of the shadow cache, or
+0 to disable it.  Since this is purely a time vs. memory trade-off,
+I decided not to make it a new command-line option.  (We already
+have plenty.)
+
+****** COMPATIBILITY CHANGE ********
+Changed the following command names to avoid conflicts:
+	rview -> rvu (with symbolic link back to rview)
+	calc -> icalc
+	lam -> rlam
+	gencat -> gencatenary
+
+Improved -f option of normpat, which caused odd color changes before.
+
+Created pgblur script which does fast Gaussian blur of image without changing
+its dimensions.  This is very useful in certain types of image processing
+calculations, such as finding or removing low frequencies.
+
+****** COMPATIBILITY CHANGE ********
+Changed little-used objpict script so that it takes scene files rather than
+rpict options on the command line, and puts everything into the right
+coordinate position automatically rather than requiring the user to do it.
+
+Added -I option to replmarks for mesh instancing.
+
+Made similar change for virtual sources to allow modifiers and aliases
+on the mirror and prism types to work properly.
+
+Rob Guglielmetti added -lw and -lh options to falsecolor to control the
+legend dimensions.  Made it so -lw 0 and/or -lh 0 turns legend off.
+
+Made it so pcompos will read everything from a stream even if it doesn't
+need it, so input commands will not receive a hangup signal.
+
+Wrote ra_bmp program to convert to and from Windows BMP files (finally).
+It's the most horrible image format I've ever seen, and I've seen a lot.
+
+Increased -aa default value for all renderers (and also -ad and -as in
+rview) at Schorsch's suggestion.  I think this undid my earlier decrease
+of -aa last time, which I guess was ill-considered.
+
+Modified oconv to keep subdividing the octree if there are too many
+objects in a voxel even when the -r resolution limit has been
+reached.  This was not done before due to problems with recursion,
+and still, it will only continue to 256 times the original -r limit.
+If that isn't enough, then there's probably no hope, anyway.
+
+Added -l option to obj2mesh to search for material files in library
+locations.
+
+Increased polygon vertex limit to 512 in obj2mesh and obj2rad and added
+warning if this limit is exceeded.
+
+Added tone-mapping and monitor primary options to ra_bmp.  This gives
+new functionality similar to normtiff and ximage.  It would be nice to
+add this feature to the other ra_* programs as well...  someday.
+
+Fixed long-standing bug in reported pixel ordering out of certain
+protate commands.
+
+Added -p option to rcalc for "passive mode" that transmits
+unrecognized input -- useful for substituting data in the
+middle of a stream.
+
+Fixed a very obscure bug in rpict that caused a dark horizontal
+line in certain cylindrical projections due to improper drawing
+of the sky dome source in rt/srcdraw.c.
+
+Fixed problems with effective ray lengths computed for dielectric
+and BRTDfunc materials.  This was most evident in breakup of holodeck
+views when VDISTANCE=True.
+
+Fixed rad so that 'scene' variable may consist only of inline commands.
+
+Fixed bug introduced in shadow caching routines where sources in the
+middle of spheres were not illuminating properly.  Thanks to Guilio
+Antonutto for spotting this problem.
+
+Modified gensky behavior so if time is given with standard time zone
+designation, any -m option is ignored.
+
+Added -n option to mkillum for (shared memory) parallel processing.
+
+Fixed a long-standing bug in parallel processing code that only
+seemed to manifest with the new mkillum -n option, where rtrace
+would deadlock upon termination.  The reason it never showed up
+before is because I always closed processes in the reverse order
+of opening them in other programs.  I went through and found similar
+(potential) bugs in the rview device subprocess code and util/netproc.c.
+
+Corrected the normalization of the Gaussian reflectance model.  This will
+cause an increase in specularity for low-lying light sources.
+Thanks to Don Walters of Boeing and Arne Duer of the Univ. of Innsbruck
+for pointing out this error.  The square root used for the two cosines
+in the denominator of the normalization factor should not be present.
+This was a serious mistake I made in the original model, which went
+undiscovered (at least to my knowledge) for over a decade.  I think
+Bruce Walter of Cornell may have known about it, but I never heard
+the details of his discovery.
+
+Enabled the -p option for primary conversion without tone-mapping
+in ra_bmp.  Also provides for XYZE input conversion to RGB.
+
+Fixed what I consider a bug in pvalue -o when taking XYZE files on input,
+where it was inappropriately undoing the exposure value so that it always
+reported radiance rather than XYZ values with Y in cd/m^2.
+
+Made it so ra_bmp only produces run-length encoded 8-bit output for
+grayscale images that are tone-mapped.  This minimizes circumstances
+under which output scanline order is reversed.
+
+Fixed bug in rcalc where it sometimes wasn't parsing the input format
+correctly.
+
+=====================
+Version 3.7 (Released 7/25/05)
+
+Fixed bug in source occluder cache which caused consistency error
+for distant sources and mist materials.  (Thanks to Mark Stock for
+finding the problem.)
+
+Fixed serious bug in source drawing routines for rpict, where the edges
+of light sources were appearing through obstructions.  (Thanks to Veronica
+Sundstedt for pointing this out.)
+
+(The above were included in the 3.6.1 patch release.)
+
+Changed default temporary directory from /usr/tmp, which doesn't exist
+on a lot of systems these days, to /tmp.
+
+Eliminated many unused files and programs from the distribution, including
+the following programs that were being built but no longer used:
+	oki20	- printer driver for OkiMate 20 printer (B&W)
+	oki20c	- printer driver for OkiMate 20 color printer
+	pcwarp	- intended as more general substitute for macbetcal,
+			but never quite worked
+	ra_avs	- convert to & from AVS image format
+	ra_bn	- convert to & from Barneyscann format
+	ra_pr	- convert to & from 8-bit Sun rasterfile format
+	ra_pr24	- convert to & from 24-bit Sun rasterfile format
+	thf2rad	- convert GDS "things file" to Radiance scene format
+If anyone is still wanting any of the above programs, let us know and we'll
+reinstate it.
+
+Fixed bug in pcond's acuity simulation for small view angles (less than
+4 degrees horizontally or vertically).  Thanks to James Lee for figuring
+this out.
+
+Added script to convert to/from ICT's Poskanzer Float Map, which I don't
+care to support officially due to its machine-dependent byte order.
+
+Fixed bug that caused incorrect reporting of non-surface in set when
+mixing meshes and instances.  (Thanks to Jack de Valpine for discovery.)
+
+Fixed inaccuracy in calculation of diffuse transmission in the presence
+of pure specular (Fresnel reflection) using "trans" material.  Thanks
+to Christoph Reinhart for pointing out the error.
+
+Made internal change to tone-mapping library to use structure pointer
+rather than stack, making code re-entrant and more up to modern standards.
+
+Added -pd option to handle depth-of-field blur in rpict.  This requires
+that the view directon (-vd option) include focal distance information,
+which is now preserved by the various view file routines, and reported
+by the vwright command.
+
+Added DBLUR variable to ranimate and pmdblur script to handle simultaneous
+motion and depth-of-field blurring.  Thanks to Visarc for funding this work.
+
+Added setting of focus distance in rvu ("focus" command) and rholo
+('f'/"frame" command).
+
+Changed default remote shell in ranimate to "ssh" rather than "rsh",
+which has been abandoned on most Unix systems due to security issues.
+
+Fixed behavior of source primitive using illum with no alternate
+material.  These now become transparent so one can see the sky or
+light-probe background for use in image-based lighting.  Previously,
+the user needed to specify the background glow as the alternate
+material for a distant illum source to behave properly.  (This still
+works.)
+
+Fixed some minor problems and inconsistencies with 16-bit/channel
+TIFF i/o in ra_tiff.
+
+Created mksource program to generate distant sources for improved
+image-based lighting with light probes.
+
+Changed ambient calculation so that -ad will not limit recursion
+depth, and a minimum of 27 samples will be sent out for each stored
+ambient value, or 3 samples if -aa is 0 (caching off).
+
+Added -oM option to rtrace to report material (rather than modifier)
+for cases where actual material is aliased or further up modifier chain.
+
+Rearranged the way ray contributions are computed so that it might be
+possible to use rtrace to derive daylight coefficients and optical
+transfer functions.  The new -oTW option of rtrace produces color
+contribution weights for each ray, which combined with the -ti (or -tI)
+option permits the contribution of selected surfaces or sources to
+be determined.  Using the -oTW option, one should also specify
+options "-dt 0 -aa 0 -as 0" for optimal results.  In particular,
+one cannot expect reasonable tallies with -ab >= 1 and irradiance
+caching on (-aa > 0).
+
+The same code modifications included a change to the indirect computation
+with caching switched off (-aa 0).  Whereas before, the number of secondary
+rays after the first bounce were half of the previous generation, they are
+now determined by the surface reflectance, making for a better and faster
+calculation.  It should now be possible to compute many bounces with -aa 0,
+which used to be prohibitively expensive.
+
+Added -T option to xshowtrace to trace rays to light sources.
+
+Added meta2bmp program to produce BMP files from metafile graphics.
+
+Added cct_x(t) and cct_y(t) to src/cal/cal/blackbody.cal to interpolate
+CIE chromaticities for particular black-body temperatures.
+
+Increased maximum number of input pictures in pcomb and pcompos to 512.
+
+Created rtcontrib program for computing ray contribution coefficients.
+This tool may be used to do standard optical ray tracing or daylight
+coefficient calculations for annual simulations, among other uses.
+
+Added tilde ('~') output option as part of the -o* specification of
+rtrace.  This permits ray trees to be parsed more easily in binary
+output mode, as needed by rtcontrib.
+
+Implemented Russian roulette ray termination with -lr <= 0.
+Made -lr -10 the default in rtcontrib.
+
+Made rtcontrib -f option search RAYPATH directories.
+
+Made it so -o option of rtcontrib can pipe -o output to a command.
+
+Added -if and -of options to total for binary i/o (following rcalc mold).
+
+Switched default options in rtrace to use Russian roulette.  (Rpict and rvu
+still use biased ray termination.)
+
+Added rtcontrib -r option to recover partial output.
+
+Added -u rendering option for pure Monte Carlo sampling.
+(Got rid of -DMC compile option, which this makes superfluous.)
+
+Changed -t option of rlam to accept strings as well as single characters.
+
+Fixed bug in rcalc with -l option where it would sometimes go into an
+infinite loop.
+
+Fixed truly ancient bug in bounding box computation for cones, which
+could (and did) cause missing segments.
+
+Added -z option to normtiff to output LZW-compressed files.
+
+Last change to total causes it to produce results when it sees an empty
+line on the input.  This was not intentional, but I decided I like this
+behavior so I documented it rather than changing it.
+
+=====================
+Version 3.8 (Released 10/17/06)
+
+Fixed Russian roulette ray termination, which was doing the opposite of
+what it should have been doing, resulting in overestimated values below
+minimum ray sampling weight (serious).
+
+Changed mksource to use 98th percentile (rather than 99th) for threshold.
+
+(Above changes included in 3.7.1 patch release.)
+
+Eliminated writing of EXPOSURE= line in ra_tiff -r when source TIFF
+does not have STONITS set.
+
+Fixed bug in ambient calculation that caused black values for multiple
+bounces in some scenes.  Thanks to Mark Stock for creating and sharing
+the sophisticated test scene that demonstrated this problem.
+
+Fixed bug in antimatter using Russian Roulette sampling.
+
+(Above changes included in 3.7.2 patch release 22 Aug 2005.)
+
+Created fieldcomb script to combine alternate fields in a rendering
+sequence.  (Development generously sponsored by Iebele Abel.)
+
+Added missing preload of mesh objects for more efficient memory use
+during parallel rendering -- this was a serious oversight.
+
+Created ran2tiff program to automate exposure setting of animation
+sequences using a moving histogram in combination with pcond, and
+converting frames to TIFF.
+
+Eliminated SPEED macro from makeall and source tree.
+
+Added -pj option to vwrays to allow jittering of sample locations.
+
+Fixed bug in rtcontrib where it occasionally missed writing the
+final bin file.  (Pretty serious, actually.)
+
+Added -Dfseeko=fseek to MACH= line for linux, as fseeko(3) seems to be
+broken in current versions of Linux.  (Need to remove this later.)
+
+Rearranged struct's for better efficiency on 64-bit architectures.
+
+Added -i option to rlam so it works with binary input formats.
+
+Added rtcontrib -bn option to specify number of bins and fixed bug
+in recovery of files containing multiple values per record.
+
+Added rtcontrib -fo option to write over existing files, which it now
+refuses to do without this option.
+
+Made rtcontrib flush output when handed a zero-length ray vector,
+to match behavior of rtrace.
+
+Improved color scale for falsecolor output.
+
+Added threshold test for Fresnel approximation to prevent its use
+on smooth surfaces with unrealistically low specularities (less than 1.8%).
+Water has a specular reflectance of 2.1% at room temperture.
+
+Removed NICE macro settings in rpict and rtrace, which was slowing down
+the processes under Mac OS X (10.4) by about 60% due to processor napping.
+
+Made xform, replmarks and rad2mgf handle quoted modifiers and names properly.
+
+Fixed problem in genblinds, where it was generating slats that were too
+wide with the +/-r option.  (Thanks to Helena Buelow-Huebe for discovering
+this bug.)
+
+Fixed bug in ra_ppm for 16-bit/sample i/o, where it was getting the byte
+order wrong (apparently).
+
+Added -V option to rtcontrib to report actual contributions, rather than
+just ray coefficients.
+
+Fixed bug in ranimate that caused it to fail in continuation of renderings.
+
+Renamed librt.a to librtrad.a, to avoid conflict on Solaris. Almost
+everything now gets linked to -lrtrad instead of -lrt.
+
+Fixed problem with large sample sets, so -u+ option now is truly random.
+Thanks to Rick Mistrick and Younju Yoon for identifying this problem,
+which was related to a poorly designed hash function.
+
+Changed -u+ to be the default setting in rtrace (only).
+
+Fixed binary i/o for rlam and vwrays under Windows.
+
+Added tmCvLums() to tone-mapping routines using a 16-bit lookup table
+on IEEE floats, which is also used to improve speed of COLOR conversions,
+especially on machines with slow log() calls.  The first call to
+tmCvLums(), tmCvGrays(), or tmCvColors() initializes the table.
+
+Created optics2rad.csh script to convert from Optics 5 material output
+to something correct for Radiance.  Built on old glazing.cal function,
+which is actually incorrect so removed from the distribution.
+
+Fixed nuisance bug in ximage under some SGI machines that caused it to
+choose an inappropriate visual and display incorrect colors.  (Thanks
+to Oskar Itzinger for debugging the problem.)
+
+Fixed long-standing inaccuracy of pcompos -t and +t thresholding options.
+
+Fixed bug in handling of views with tabs rather than spaces.
+
+Fixed bug related to alias of alias.
+
+****** COMPATIBILITY CHANGE ********
+Changed default sky turbidity in gensky from the original default of
+2.75 to the CIE 110-1994 standard value of 2.45.  Thanks to Marilyne
+Anderson of MIT for pointing out this discrepancy.
+
+Added -o option to ra_xyze to produce original pixel values.
+
+Fixed bug in tracing of virtual sources, where intervening glazing was
+not being accounted for properly.
+
+Added -h option to pcompos and pcomb to eliminate verbose headers.
+
+=====================
+Version 3.9 (Released 3/30/08)
+
+Added -spec option to falsecolor to restore original spectral color scale.
+Also added "-s auto" option to automatically set the maximum value.
+
+Added byte-swapping input and output to rcalc.
+
+Additional error-checking for source surfaces.
+
+Re-fixed bug in octree code that caused it to allocate 8 times as
+much memory as it actually used(!) -- this was pointed out way back
+in 1999 by Erik Reinhard and Erik Jansen, but the fix they gave me
+got lost in the slightly broken release process at the time.  This
+should make a big difference in memory usage, especially for the
+new mesh primitive.  (I measured 30% less memory usage.)
+
+Corrected ray weights for material mixtures.
+
+Reduced the default -n setting for obj2mesh to take better advantage
+of the smaller octree structure size.
+
+Fixed bug in shadow cache where it was adding surfaces with antimatter
+holes cut in them to the obstructor list.  Thanks to John Mardaljevic
+for discovering and reporting the problem.
+
+Adding ability in mkillum to incorporate BSDF data in calculation.
+Internal interface (raypcalls) now used in place of rtrace process(es).
+
+Fixed pixel alignment in pcomb for size reduction and enlargement.
+
+Allow rtcontrib user to set -P and -PP options for persistent rendering.
+The only caveat is that -n setting > 1 requires -PP rather than -P.
+
+Added -c option to rtcontrib to facilitate cumulative calculations.
+
+****** COMPATIBILITY CHANGE ********
+Fixed long-standing bug in source.cal, which caused it to produce
+reversed anisotropic photometric distributions due to the
+misorientation of the y-axis.  Thanks to Zack Rogers for discovering
+and helping debug this problem.
+
+Fixed long-standing bug in replmarks, where triangles with X-side
+aligned with Z-axis would cause incorrect rotations.  Thanks to
+Zack Rogers for finding this error.
+
+Added rsensor program to compute sensor signal for daylighting controls.
+Funding for this component was provided by the Architectural Energy
+Corporation in Boulder, CO, and directed by Zack Rogers.
+
+Added "planisphere" (stereographic) fisheye view type for traditional
+daylighting analysis.  Feature requested & explained by Axel Jacobs.
+
+Modified -c option to rtcontrib so it can take a number of input
+rays to average over, rather than only produce a single accumulated
+record (which can now be done with -c 0).
+
+=====================
+Version 4.0 (Released 3/12/10)
+
+Added -n option to rvu to provide parallel rendering.
+
+****** COMPATIBILITY CHANGE ********
+Changed ".pic" extension to ".hdr" in all sources and documentation
+to improve interoperability with other software, since this has become
+the de facto extension for Radiance RGBE and XYZE pictures.  Since file
+extensions were never more than a convention in Radiance, this does not
+affect operation, but may require the update of scripts, etc. written
+by others that assume the ".pic" suffix for Radiance output.
+
+Added -N option to objview to support multiprocessing.
+
+Improved sampling of circular sources (source, sphere, ring types) with
+quite a bit of help from David Geisler-Moroder.
+
+Added "rpict" and "rvu" variables to rad, and made these as well as
+the "oconv", "mkillum" and "pfilt" variables accept an alternate
+command path in each case.  Change suggested by Lars Grobe based
+on similar Radzilla (radz) facility by Carsten Bauer.
+
+Fixed rad -v N specification to use actual view name if one.
+
+Fixed error in mkillum calculation where it neglected indirect
+source contributions from BTDF illum's.
+
+Added GMT and LATLONG header lines for Greenwich Mean Time and
+degrees North Latitude / East Longitude.
+
+Added gendaylit to distribution (finally).
+
+Added ability in vwright(1) to get view from command line arguments.
+
+Created genklemsamp(1) utility to generate samples suitable for
+BSDF-based annual calculations.  This is the first Perl script to
+be added to Radiance.  Hopefully, others will follow.
+
+Added klems_int.cal file to compute Klems bins for windows.
+
+Created genskyvec  utility to sample a particular sky and
+evaluate average radiance over the standard Tregenza sky patches.
+
+Created dctimestep program to compute a set of sensor values or
+a combined image for a particular time using the daylight
+coefficient method.
+
+Created src/rt/rayfifo.c for first-in/first-out handling of
+multiprocessing by raypcalls.c.
+
+Added -n option to rtrace for executing on multiple cores
+using new rayfifo calls.
+
+=====================
+Version 4.1 (Released 11/04/2011)
+
+Changed ranimate behavior so remote login under a different user
+doesn't necessarily require the presence of the originating user's
+home directory.
+
+Changed standard transmission function normalization back to what
+it was in version 3.5, following recommendation of David Geisler-Moroder,
+who pointed out that the revised BTDF increased too much at grazing.
+
+Changed rad behavior with -N >1 on single view to call rpiece.
+
+Updated SCons build system for MINGW compilation, thanks to Christian
+Kohler.
+
+Added -u option to rlam for unbuffered output.
+
+Modified dctimestep to accept sky vector and daylight coefficient matrix
+or list of images to sum together, as suggested by Andy McNeil.
+
+Created genBSDF script to generate BSDF in Windows XML format.
+
+Modified mkillum to accept detailed geometry from BSDF XML files.
+
+Altered obj2rad to ignore zero normals (thanks to Jack de Valpine for
+suggestions and help).
+
+Fixed bug in genklemsamp that caused non-uniform sampling over surfaces.
+
+Fixed bugs in rhoptimize and rhcopy for 64-bit compilation.
+
+Made a change to avoid problem using gcc --fast-math compile option.
+
+****** COMPATIBILITY CHANGE ********
+Changed behavior of rtrace and rtcontrib so that every scanline is
+not flushed when both -x and -y are set.  This avoids flush delays
+in rtcontrib for large numbers of output files and delays while
+rendering images using rtrace with the -n option.
+
+Added ability for rsensor to output ray origins and directions
+rather than actually loading octree and computing sensor value.
+
+Fixed old bug in obj2rad where it would stop processing and
+report a syntax error if the "void" type is used in the map file.
+
+Updated reflection model according to EGSR 2010 paper by David
+Geisler-Moroder and Arne Duer.
+
+Replaced C-shell version of falsecolor with Perl script written
+by Axel Jacobs.
+
+****** COMPATIBILITY CHANGE ********
+Changed -sj (specular jitter) option to something called specular
+sampling (-ss), which if set less than 1 has the same behavior as
+the old -sj, but when set greater than 1, spawns multiple ray
+samples from semi-specular surfaces.
+
+Fixed bug noticed by Randolph Fritz that caused ambient sync errors.
+
+Fixed bug in findglare for reading picture files under Windows.
+
+Added options to pvalue to note other color spaces on reverse conversion.
+Thanks to Erich Philips for the feature request.
+
+Added BSDF data-driven material type with full sampling support.
+
+Added BRDF calculations to genBSDF.
+
+Bug fixes in rsensor thanks to help from David Geisler-Moroder.
+
+Added variable-resolution BSDF support in renderers and genBSDF.
+
+Created pkgBSDF program to extract BSDF geometry and put it
+together with surface description suitable for inclusion in
+a Radiance scene.
+
+Muted warning for "no light sources found" when there is at least
+one glow object and interreflections are on (-ab > 0).
+
+Fixed long-standing bug that caused underestimation of reflection
+when specular component was below -st threshold in non-metals.
+
+Checked in cross-platform cmake build system created by Bill Hoffman
+of KitWare and sponsored by NREL.  This includes a qt-based
+driver for rvu, which is built in the new subdirectory src/qtrvu.
+
+=====================
+Version 4.2 (Release date 7/31/2014)
+
+Axel Jacobs added -cp and -palettes options to falsecolor.
+
+Fixed bug in matrix output of genBSDF introduced shortly before 4.1 release.
+
+Made rvu more responsive in multi-processing mode when changing parameters.
+Explicit "new" command not needed to show changes, because it goes back
+to "immediate mode" once something is changed.  Processing will be slow
+but response time quick until next "new" command.
+
+Fixed major bug in transmitting proxy material sampling.
+
+Patched cmake build tools (changes by Zack Galbreath).
+
+Removed requirement for pflip -h to be given input file (can pipe from stdin).
+
+Added "Number of processes" slider to trad "Action" pane to control rad -N
+option for rvu and batch rendering.
+
+Added -c option to vwrays to repeat pixels for rtcontrib.
+
+Reworked rtcontrib program and renamed to rcontrib.  New version runs much
+faster, especially on multiprocessor systems, and doesn't require as much
+memory.  No longer calls rtrace; instead does all the work itself.
+
+Added -d option to genskyvec to produce direct-only (sun no sky) vector.
+
+Added Ashikhmin-Shirley anisotropic BRDF model (ashik2) with help
+from Nicolas Boneel.
+
+Added Ruby rewrite of objview.csh by Rob Guglielmetti.
+
+Fixed bug in reciprocity for tensor tree BTDF representations.  Thanks
+to Andy McNeil for identifying the problem.
+
+Added MNAME and ZNAME variables to ranimove for debugging & testing.
+
+Created pmblur2 command to take motion and depth buffers from ranimove
+to compute a better motion blur.
+
+****** COMPATIBILITY CHANGE ********
+Changed BSDF routines to use updated/corrected XML specification and
+removed depracated BSDF support from mkillum.
+
+Fixed behavior of i/o flushing in rcontrib with -c > 1 (averaging).  Thanks
+to Lars Grobe for help identifying this problem.
+
+Fixed bug in depth-of-field blur where view distance was measured from
+fore clipping plane rather than viewpoint.  Thanks to Peter A-B for
+pointing this out.
+
+Added options to dctimestep to allow multiple time steps (-n)
+and multiple output pictures or sensor files (-o).  Also added -i
+option to specify float (-if) or double (-id) input for sky matrix.
+
+Created gendaymtx program to compute annual sky patch matrix based
+on Ian Ashdown's implementation of Perez all-weather sky model.
+Output can be sent directly to dctimestep in ASCII or binary stream.
+
+Replaced existing gendaylit.c with improved version from Wendelin Sprenger
+and Jan Wienold of ISE.
+
+Improved accuracy of ambient calculation for large -ad settings.  Thanks
+to Lars Grobe for noticing the problem.
+
+Added -r option to gendaymtx to rotate the sky the specified number of
+degrees about the zenith as suggested by A. McNeil.
+
+Axel Jacobs added -pal eco color map that does a blue-red-yellow scale.
+
+Created bsdf2klems tool to convert from various BSDF representations to
+Klems basis matrix in XML file.
+
+Fixed problem with inappropriate reciprocity enforcement on tensor
+tree reduction in genBSDF.  (Thanks to A.McNeil for discovering issue.)
+
+Fixed bug in isotropic tensor tree sampling for impinging rays
+exactly normal to surface.  Thanks to Peter Apian-Bennewitz for
+discovering and pointing out the error.
+
+Fixed double-counting bug in mirror material with alternate type.
+Thanks to David Geisler-Moroder for spotting the problem and helping
+to fix it.
+
+Created rcollate program to resize and transpose matrix data for Andy
+McNeil's 5-phase annual simulation method.
+
+Added epw2wea conversion program by Christoph Reinhart.
+
+Implemented Perlin's improved noise function with help from Rahul Narain.
+This will change the appearance of renderings using this function.
+
+Added "origin" command to rvu as requested by John Mardaljevic
+to place view origin at selected point in scene.
+
+Switch to Perl versions of objview and objpict written by Axel Jacobs.
+
+Improved rendering speed of scenes with aliases by not entering new
+modifiers into table if they are the same as the previously defined
+modifier for that name.
+
+Made it so icalc and rcalc search RAYPATH directories for *.cal files
+given on command line.  This simplifies script writing and makes these
+utilities consistent with other tools in Radiance.
+
+Added triangulation routine to handle convex polygons in obj2mesh.
+
+****** COMPATIBILITY CHANGE ********
+Made backface visibility apply to all material types, including
+transparent and translucent materials (except dielectric and interface).
+This makes the option useful in cases where adjacent trans surfaces
+are placed next to each other by a modeler that only understands
+volumetric objects.
+
+Changed dctimestep so that output matrices (-n > 1) are preceded by a
+header, and added support for float and double output formats with -o[fd].
+
+Introduced eplus_adduvf program to compute user view factors for EnergyPlus.
+
+Changed image-plane sampling in rpict to use Hilbert curve, which gives
+less of a brushed/striped appearance to output pixels with -u- (default).
+
+Added ltview and ltpict Perl scripts contributed by Axel Jacobs, inspired
+by Rob Guglielmetti.
+
+Added header variables for NROWS, NCOLS and NCOMP to help standardize
+matrix files.  This functionality has been incorporated into
+rcollate, gendaymtx, and dctimestep.
+
+Created rmtxop utility to operate on multi-component matrices.  This
+facilitates some daylight matrix calculations, and provides a general
+tool for manipulating matrix data.
+
+****** COMPATIBILITY CHANGE ********
+Introduced new Hessian-based error control in irradiance caching (ambient)
+calculation.  Since the format of the stored ambient values is different,
+the old files will be rejected with an error message and must be removed.
+The programs may be compiled with the -DOLDAMB option if this is a problem.
+
+Added -p option to rcontrib to set function file parameters on a per-modifier
+basis to simplify bin evaluation.
+
+Created rfluxmtx program to compute flux transfer matrices from a sender
+surface to one or more receiver surfaces.  (Renamed the file klems_int.cal
+to klems_full.cal in the process.)
+
+Added "-c" option to getinfo to execute command on data segment.
+
+================================
+Version 5.0 (Released 9/18/2015)
+
+Changed rmtxop so it writes out same type as lesser of inputs unless
+directed otherwise using -f? option.
+
+Changed order of oconv arguments in rfluxmtx so user can specify input
+octree using -i option at the end instead of (or in addition to) a
+list of scene files.
+
+Added support for argument expansion to rfluxmtx and bug fixes.
+
+Fixed bug in indirect hemisphere sampling for some corner cases.
+
+Added default specular lobe to BSDF interpolation.
+
+Set minimum number of shadow checks before direct optimization (4).
+
+(Above changes included in 4.2.1 patch release.)
+
+****** COMPATIBILITY CHANGE ********
+Made header input and output the default behavior for dctimestep and
+genskyvec.
+
+****** COMPATIBILITY CHANGE ********
+Changed pabopto2bsdf default behavior to add 90-degree rotation
+to bring pgII's definition of "up" in line with Klems axis
+conventions.  Introduced a new header variable "upphi" to
+control this added rotation.  Using "#upphi 90" in each
+BSDF input file gets back the original behavior, where it
+assumes that the up direction is 90-degrees from the X-axis.
+The default value of 0 corresponds to PAB's definition of
+the X-axis as being "up".
+
+Fixed bug in rsensor related to having many rows (altitude) and
+few columns (azimuth) in sensitivity file.
+
+Fixed floating point round-off error in new Hessian calculation
+for some sytems (Windows, primarily).
+
+Fixed bug in tensor tree BSDF code that caused bus error on
+some systems, and may have been source of other errors as well.
+
+(Above changes included in 4.2.2 patch release.)
+
+Improved ambient extrapolation to avoid zero values.  Actual
+threshold set to 5% of recorded value.
+
+Changed anisotropic Gaussian and Ashikhmin models so that
+illegal orientation vectors are dealt with more gracefully.
+
+Created wrapBSDF tool and incorporated into genBSDF along
+with new rfluxmtx computation.
+
+Initial check-in of Roland Schregle's photon map integration.
+New 5.0a version designation as suggested by Andy McNeil.
+
+Added left-hand coordinate sytems to rfluxmtx to correct
+problems with coordinate axis orientations pointed out by
+David Geisler-Moroder.
+
+Added color output to genBSDF (+C option) and support for
+color rendering of Klems and tensor tree data.
+
+Fixed another bug in rsensor that caused rays to be generated
+on opposite side of hemisphere even where sensitivity was zero.
+
+Fixed bug discovered by Jacob Jonsson in Klems BSDF
+interpolator that caused it to over-predict normal
+transmittance and reflectance.
+
+Added ability to read input from commands in dctimestep
+and rmtxop.
+
+Added photon map support to rad.  Fixed some double-counting
+issues in photon-mapping spotted by David Geisler-Moroder.
+
+Added photon map support to trad.
+
+Fixed bug in antimatter source testing when antimatter
+definition follows potential obstructor in input.
+
+Fixed issue with missing character type identifier at head
+of genBSDF XML output.
+
+Prompted by Roland S., added option to have pcompos -a order
+rows from top rather than bottom of image.
+
+Changed dctimestep to accept matrix as well as BTDF input
+in the VTDs invocation mode.  This permits the output of
+rmtxop to be used in a pinch when combining multiple BTDF
+layers, although interreflection between layers is not
+accounted for properly as it is in the WINDOW program.
+
+Added Jan Wienold et al.'s evalglare to distribution.
+
+Hopeful fix to deadlock issue under Mac OS X 10.10.x (Yosemite).
+
+Fixed early exit of rcontrib with internal error (sample behind sender)
+discovered by Rob G.
+
+=================================
+Version 5.1 (Released 8/17/2017)
+
+Fixed issue with vchars.mta and symbols.mta not being installed in
+the appropriate metafile library location, with help from Rob G.
+
+Added ability to give quoted strings to output= directive in rfluxmtx.
+
+****** COMPATIBILITY CHANGE ********
+Added ability to digest color (CIE-XYZ) input in pabopto2bsdf.
+This change alters the .sir (interpolant) format, so these files
+will need to be regenerated.  Use the new "#colorimetry: CIE-XYZ" tag
+to enable on input.
+
+Rewrote bsdf2klems to support tristimulus color and call wrapBSDF.
+Did the same for bsdf2ttree.  Function specifications still gray only.
+
+Reduced a problem where rvu or rholo would be slow to quit when
+run with many processes on a large model or one with a large
+ambient file (taking lots of memory).  We were waiting for
+processes to quit one-by-one, which takes some time for each
+process as it disentangles its shared memory.  We now
+wait for all the processes together, so they can disentangle
+in parallel.  It can still take up to a minute in some cases,
+but not 10 minutes like it was taking before the fix.
+
+Enabled ambient cache value corral for all levels, not just final two.
+This may reduce errors in certain pathological scenes.
+
+Added -in option to rcalc, rlam, and total to limit the number of
+input records in hopes of circumventing Windows EOF issues on binary data.
+Also added -on option to rcalc and total for logical symmetry.
+
+Increased modifier limit to 10,000 in rcontrib.
+
+Fixed issues with glrad and added zoom response to mouse wheel input.
+
+Added missing definition of "ashik2" material type to reference manual.
+
+Changed genBSDF to calculate device thickness assuming Zmax==0 so
+pkgBSDF will generate correct proxy geometry.
+
+Created pabopto2xyz tool to combine different sensor measurements
+into a single CIE-XYZ measurement file for color BSDF interpolation.
+
+Jan Wienold updated evalglare to version 1.30
+
+Roland Schregle added out-of-core photon mapping routines, which
+may be compiled using the PMAP_OOC macro.
+
+Added -a option to getinfo for easy addition of header lines.
+
+Fixed issue with multiple records on picture output in rcontrib (and rfluxmtx).
+Credit to Sarith Subramaniam for pointing out the problem.
+
+Made mkillum more tolerant of non-planar polygons in its sampling routines.
+
+Added "-recover" option to genBSDF to pick up where it left off.
+
+Fixed genBSDF issue that was created incorrect normalization of
+Klems output.  Thanks to David G-M and Christian Knoflach for
+discovering the error.  Also improved sampling of indirect irradiance
+that showed some slight bias due to poor sample collision avoidance.
+
+Fixed long-standing issue with -aa 0 neglecting textures in calculating
+surface shading.
+
+Fixed bug in ranimove introduced during photon map integration.
+
+Added check for steep sections of BSDF in pabopto2bsdf, creating narrower
+peakes in those places and mitigating some normalization issues.
+
+Added view360stereo.cal by Mark Stock to handle 360-degree over/under
+stereo views.
+
+Added MAX2SHADE macro to place limit on number of light sources
+to precheck for obstructions.  (Currently set to 200.)  This
+avoids excessive start-up times for scenes with many light sources.
+Thanks to Axel Jacobs for pointing out the problem.
+
+Added -v option to obj2mesh to print out mesh statistics.
+
+Rewrote bsdf2rad from ground up and made it a standard part of build.
+
+Fixed bug in orientation of Reinhart/Tregenza sample generator in rfluxmtx.
+
+Added ability to perform shadow-testing through unproxied BSDFs with strong
+through (direct-direct) component.
+
+Added {+|-}a options to genBSDF and bsdf2ttree for switching off reciprocity
+averaging.
+
+Added bias to see through BTDFs with a strong "through" component
+rather than scattering view rays.  This is in lieu of peak extraction,
+which looked to be too difficult from an implementation standpoint.
+
+Added bsdfview tool analogous to objview but for BSDF files (XML and SIR),
+which calls bsdf2rad then rad with a few useful default views.
+
+=========================
+Version 5.2 (Release October 8, 2018)
+
+Created psketch program to apply non-photorealistic rendering to selected
+objects, identified by modifier name(s).
+
+Added '*' and '/' operations to rmtxop for element-wise multiplication and
+division of same-sized matrices.
+
+Changed falsecolor so "-s" option is adjusted to match legend if one.
+
+Falsecolor legend changes and improvements by David G-M and Stephen W.
+
+Fixed bug in peak extraction code that generated
+"Bad call to SDqueryTreProjSA" error, reported by Lars Grobe.
+
+Increased maximum luminance to 10^7 in pcond to fix issue noticed
+by Axel Jacobs where veiling glare not added for the sun under
+some conditions.
+
+Increased maximum number of open files in rcontrib to the system upper
+limit of 2048 rather than the default 512 under Windows.
+
+Added top-level resources directory with files from Rob Guglielmetti.
+
+Improved accuracy for peaky BSDFs and small light sources.
+
+Fixed issue with pmapdump noted by Axel Jacobs.
+
+Improved accuracy of bsdf2ttree when converting scattering interpolation
+representatons with strong peaks.
+
+Tweaked peak-extraction code to work more reliably.
+
+Georg Mischler updated SCons build system.
+
+Rob Guglielmetti and Alex Swindler updated CMake build system.
+
+Modified pcomb so the first view seen in the inputs is written into header.
+
+Wrote rtpict script to run rtrace in parallel mode and simulate rpict with
+-n option.
+
+Added ability to move forwards/backwards specified distance in rvu "origin"
+command.  Feature requested by John Mardaljevic, who essentially owns this
+command, now.
+
+Reduced bias in ambient super-sampling method.
+
+Fixed bugs associated with zero transmission in chromatic tensor trees.
+Thanks to Lars Grobe for pointing out issues.
+
+Added RAYPATH searching for -f options to genrev, gensurf, genworm,
+bsdf2klems, bsdf2ttree, and pcomb.  This makes behavior consistent
+with rcalc, calc, and rendering tools.
+
+Worked with Randolph Fritz to fix some issues with ies2rad and newer
+IESNA63 standards.
+
+Resurrected original bsdf2rad test program, renaming it bsdf2rado. Still an
+optional build in src/cv/.
+
+Fixed bug in rcontrib with virtual sources, where pretest was adding
+to modifier accumulation buffers.  Reported by Mostapha.
+
+Added an "aBSDF" material type that explicitly checks for peak extraction.
+Its arguments are the same as the original "BSDF" type, but without the
+thickness parameter, as proxy geometry is not supported by this new type.
+The old "BSDF" type no longer does peak extraction under any circumstances,
+since this behavior is superfluous for proxied geometry.
+
+Added -r option to bsdf2rad (and bsdfview) to fix BSDF min and max range
+for comparing BSDFs.
+
+Fixed issue with pfilt -m option and uneven image size changes pointed
+out by Rob Shakespeare.
+
+Updates to evalglare and gendaylit from Jan Wienold, including new
+colored sky option.
+
+=========================
+Version 5.3