fix: Corrections to source skip test, mostly for SSKIPOPT option

perf: Improved source scatter sampling

feat(rpict,rtrace,rcontrib,rtpict): Hyperspectral rendering (except photon map)

fix: sources were returning black from backside with back visibility off

fix: logical error -- single transparent illum would end up visible

refactor: added default initialization of RAY ron, rod members

perf: moved source blocker intersection call before material evaluation

Added precautionary testing when checking for FHUGE

Improved findmaterial()'s ability to check alias branches

Revised PMAP overcounting macros in pmapmat.h, added one in badcomponent()
for overcounted caustics from transferred shadow/ambient rays

Moved source obstructor initialization out of source checking loop(!)

Set minimum number of shadow checks to perform (4)

Eliminated warning for "no light sources found" under normal circumstances

Fixed Windows bug in mkillum by initializing rmax

Changed intens() call back to bright() as recommended by David Geisler-Moroder

Fixed bug in virtual sources with intervening transmitters

Changed bright() to intens() in a couple of places for consistency

Got rtcontrib working and wrote basic man page

Eliminated revf member from RAY struct, as it was never really needed

Made illum work properly with distant source objects

Added shadow cache checking to mist scattering for better efficiency.

Allow intervening modifiers and aliases in virtual source materials

Bug fix in source substructuring test and added debug bounds checking

Minor fixes to source occlusion cache

Fixed potential bug associated with last change allowing pretextured sources

Added grouping parens to reduce ambiguity warnings.

Changed source marking routines not to look past non-instanced objects

First working version of new "mesh" primitive, obj2mesh converter

Changes and check-in for 3.5 release
Includes new source files and modifications not recorded for many years
See ray/doc/notes/ReleaseNotes for notes between 3.1 and 3.5 release

added setting of r->robj for rv2.c

improved scattering calculation accuracy

changed mixtures so that mixing material with void is allowed
also altered general behavoir so that surfaces without materials are invis.

fixed bug in srcscatter() for source subsampling

added M_MIST (mist) type and global participating medium

added raydist() function

bug fixes associated with material mixtures

made mod suggested by Bob Clear in use of statistics in direct()

made it so glow could not illuminate through an illum surface

changed -di to ! -dv

added struct pointer to improve the efficiency of direct() slightly

moved sourcehit() from srcsupp.c back to source.c

tightened up test for no contributing sources

updated revision number for release 2.0

made srcsizerat adjust with ray weight

added source sampling (-ds option)

changed urand sampling to use Peano curve through n dimensions

fixed bugs in virtual sources through prisms

fixed problem with urand on multiple dimensions

added macros for object functions

major reorganization using dispatch table for source types

added virtual sources

added stratified random sampling with urand

eliminated incorrect summation of probabilities in direct()

minor cleanup in srcray()

added warning for srcray() failure in direct()

added casts to free() calls

Added rt field to RAY structure for more accurate z-buffering

Fixed bug in source ray initialization in direct()

Removed debug statement

fixed bug in counting of small sources

Fixed bug in find routine when all contributions zero

Changed starting probability for source testing

Changed sorting array to reduce memory exchange time in qsort

Minor modifications to direct approximation

Changed intens() to bright(), which is better measure of visibility

fixed bug, forgot to set rofx and robx in sourcehit()

Initial revision