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Revision 1.1 by greg, Tue Mar 11 19:20:20 2003 UTC vs.
Revision 1.49 by greg, Fri May 30 16:35:52 2025 UTC

# Line 1 | Line 1
1 < .\" RCSid "$Id"
1 > .\" RCSid "$Id$"
2   .\" Print using the -ms macro package
3 < .DA 1/20/99
3 > .DA 12/09/2024
4   .LP
5 < .tl """Copyright \(co 1996 Regents, University of California
5 > .tl """Copyright \(co 2024 Regents, University of California
6   .sp 2
7   .TL
8   The
# Line 10 | Line 10 | The
10   .br
11   Synthetic Imaging System
12   .AU
13 < Greg Ward
13 > Building Technologies Department
14   .br
15   Lawrence Berkeley Laboratory
16   .br
17 < 1 Cyclotron Rd.
17 > 1 Cyclotron Rd., MS 90-3111
18   .br
19   Berkeley, CA  94720
20 – .br
21 – (510) 486-4757
20   .NH 1
21   Introduction
22   .PP
# Line 49 | Line 47 | which produces a picture from a scene description.
47   is a variation of
48   .I rpict
49   that computes and displays images interactively.
50 + Other programs (not shown) connect many of these elements together,
51 + such as the executive programs
52 + .I rad
53 + and
54 + .I ranimate,
55 + the interactive rendering program
56 + .I rholo,
57 + and the animation program
58 + .I ranimove.
59 + The program
60 + .I obj2mesh
61 + acts as both a converter and scene compiler, converting a Wavefront .OBJ
62 + file into a compiled mesh octree for efficient rendering.
63   .PP
64   A scene description file lists the surfaces and materials
65 < that make up a specific environment.
66 < The current surface types are spheres, polygons, cones,
67 < and cylinders.
68 < They can be made from materials such as plastic, metal,
69 < and glass.
70 < Light sources can be distant disks as well as local spheres, discs and
71 < polygons.
65 > that  make up a specific environment.  
66 > The current surface types are  spheres,  polygons,  cones,  and  cylinders.
67 > There is also a composite surface type, called mesh, and a pseudosurface
68 > type, called instance, which facilitates very complex geometries.
69 > Surfaces can be made from materials such as plastic, metal, and glass.  
70 > Light sources can be distant disks as well as  local spheres, disks
71 > and polygons.
72   .PP
73   From a three-dimensional scene description and a specified view,
74   .I rpict
# Line 84 | Line 95 | It is stored as ASCII text, with the following basic f
95   # comment
96  
97   modifier type identifier
98 < n S1 S2 S3 .. Sn
98 > n S1 S2 "S 3" .. Sn
99   0
100   m R1 R2 R3 .. Rm
101  
# Line 112 | Line 123 | primitives.
123   Thus, the same identifier may be used repeatedly, and each new
124   definition will apply to the primitives following it.
125   .FE
126 < An identifier can be any string (i.e. sequence of non-blank
116 < characters).
126 > An identifier can be any string (i.e., any sequence of non-white characters).
127   The
128   .I arguments
129   associated with a primitive can be strings or real numbers.
130   The first integer following the identifier is the number
131   of string arguments, and it is followed by the arguments themselves
132 < (separated by white space).
132 > (separated by white space or enclosed in quotes).
133   The next integer is the number of integer arguments, and is followed
134   by the integer arguments.
135   (There are currently no primitives that use them, however.)
# Line 129 | Line 139 | by the real arguments.
139   An alias gets its type and arguments from a previously defined primitive.
140   This is useful when the same material is used with a different
141   modifier, or as a convenient naming mechanism.
142 + The reserved modifier name "inherit" may be used to specificy that
143 + an alias will inherit its modifier from the original.
144   Surfaces cannot be aliased.
145   .PP
146   A line beginning with an exclamation point, `!',
# Line 140 | Line 152 | confusion will result.
152   A command may be continued over multiple lines using a backslash, `\\',
153   to escape the newline.
154   .PP
155 < Blank space is generally ignored, except as a separator.
155 > White space is generally ignored, except as a separator.
156   The exception is the newline character after a command or comment.
157   Commands, comments and primitives may appear in any combination, so long
158   as they are not intermingled.
# Line 148 | Line 160 | as they are not intermingled.
160   Primitive Types
161   .PP
162   Primitives can be surfaces, materials, textures or patterns.
163 < Modifiers can be materials, textures or patterns.
163 > Modifiers can be materials, mixtures, textures or patterns.
164   Simple surfaces must have one material in their modifier list.
165   .NH 3
166   Surfaces
# Line 221 | Line 233 | mod cone id
233   .LP
234   .UL Cup
235   .PP
236 < A cup is an inverted cone (i.e. has an inward surface normal).
236 > A cup is an inverted cone (i.e., has an inward surface normal).
237   .LP
238   .UL Cylinder
239   .PP
# Line 260 | Line 272 | mod ring id
272   A mesh is a compound surface, made up of many triangles and
273   an octree data structure to accelerate ray intersection.
274   It is typically converted from a Wavefront .OBJ file using the
275 < obj2mesh program.
275 > .I obj2mesh
276 > program.
277   .DS
278   mod mesh id
279   1+ meshfile transform
280   0
281   0
282   .DE
283 + If the modifier is "void", then surfaces will use the modifiers given
284 + in the original mesh description.
285 + Otherwise, the modifier specified is used in their place.
286   The transform moves the mesh to the desired location in the scene.
287   Multiple instances using the same meshfile take little extra memory,
288   and the compiled mesh itself takes much less space than individual
# Line 278 | Line 294 | permitting very detailed geometries that would otherwi
294   available memory.
295   In addition, the mesh primitive can have associated (u,v) coordinates
296   for pattern and texture mapping.
297 < These are made available to function files via the Lu and Lu variables.
297 > These are made available to function files via the Lu and Lv variables.
298   .LP
299   .UL Instance
300   .PP
# Line 316 | Line 332 | The basic types are given below.
332   .LP
333   .UL Light
334   .PP
335 < Light is the basic material for self-luminous surfaces (i.e. light
335 > Light is the basic material for self-luminous surfaces (i.e., light
336   sources).
337   In addition to the source surface type, spheres, discs (rings with zero
338   inner radius), cylinders (provided they are long enough), and
# Line 376 | Line 392 | Spotlight is used for self-luminous surfaces having di
392   As well as radiance, the full cone angle (in degrees)
393   and orientation (output direction) vector are given.
394   The length of the orientation vector is the distance
395 < of the effective focus behind the source center (i.e. the focal length).
395 > of the effective focus behind the source center (i.e., the focal length).
396   .DS
397   mod spotlight id
398   0
# Line 386 | Line 402 | mod spotlight id
402   .LP
403   .UL Mirror
404   .PP
405 < Mirror is used for planar surfaces that produce secondary
405 > Mirror is used for planar surfaces that produce virtual
406   source reflections.
407   This material should be used sparingly, as it may cause the light
408   source calculation to blow up if it is applied to many small surfaces.
# Line 406 | Line 422 | mod mirror id
422   0
423   3 red green blue
424   .DE
425 + While alternate materials that are reflective will appear as normal,
426 + indirect rays will use the mirror's reflectance rather than the
427 + alternate type.
428 + Transmitting materials are an exception, where both transmission and
429 + reflection will use the alternate type for all rays not specifically
430 + targeting virtual light sources.
431 + In this case, it is important that any reflections be purely specular
432 + (mirror-like) and equal to the mirror's reflectivity
433 + to maintain a valid result.
434 + A pure diffuse reflection may be added if desired.
435 + .PP
436 + The mirror material type reflects light sources only from the front side
437 + of a surface, regardless of any alternate material.
438 + If virtual source generation is desired on both sides, two coincident
439 + surfaces with opposite normal orientations may be employed to achieve
440 + this effect.
441 + The reflectance and alternate material type may be
442 + different for the overlapped surfaces,
443 + and the two sides will behave accordingly.
444   .LP
445   .UL Prism1
446   .PP
447   The prism1 material is for general light redirection from prismatic
448 < glazings, generating secondary light sources.
449 < It can only be used to modify a planar surface (i.e. a polygon or disk)
448 > glazings, generating virtual light sources.
449 > It can only be used to modify a planar surface (i.e., a polygon or disk)
450   and should not result in either light concentration or scattering.
451   The new direction of the ray can be on either side of the material,
452   and the definitions must have the correct bidirectional properties
453 < to work properly with secondary light sources.
453 > to work properly with virtual light sources.
454   The arguments give the coefficient for the redirected light
455   and its direction.
456   .DS
# Line 475 | Line 510 | a perfectly scattering medium (no absorption).
510   The scattering eccentricity parameter will likewise override the global
511   setting if it is present.
512   Scattering eccentricity indicates how much scattered light favors the
513 < forward direction, as fit by the Heyney-Greenstein function:
513 > forward direction, as fit by the Henyey-Greenstein function:
514   .DS
515   P(theta) = (1 - g*g) / (1 + g*g - 2*g*cos(theta))^1.5
516   .DE
# Line 564 | Line 599 | direction vector
599   These three expressions (separated by white space) are evaluated in
600   the context of the function file
601   .I funcfile.
602 < If no function file is required (i.e. no special variables or
602 > If no function file is required (i.e., no special variables or
603   functions are required), a period (`.') may be given in its
604   place.
605   (See the discussion of Function Files in the Auxiliary Files section).
# Line 606 | Line 641 | mod trans2 id
641   8 red green blue spec urough vrough trans tspec
642   .DE
643   .LP
644 + .UL Ashik2
645 + .PP
646 + Ashik2 is the anisotropic reflectance model by Ashikhmin & Shirley.
647 + The string arguments are the same as for plastic2, but the real
648 + arguments have additional flexibility to specify the specular color.
649 + Also, rather than roughness, specular power is used, which has no
650 + physical meaning other than larger numbers are equivalent to a smoother
651 + surface.
652 + Unlike other material types, total reflectance is the sum of
653 + diffuse and specular colors, and should be adjusted accordingly.
654 + .DS
655 + mod ashik2 id
656 + 4+ ux uy uz funcfile transform
657 + 0
658 + 8 dred dgrn dblu sred sgrn sblu u-power v-power
659 + .DE
660 + .LP
661 + .UL WGMDfunc
662 + .PP
663 + WGMDfunc is a more programmable version of trans2,
664 + with separate modifier paths and variables to control each component.
665 + (WGMD stands for Ward-Geisler-Moroder-Duer, which is the basis for
666 + this empirical model, similar to the previous ones beside Ashik2.)\0
667 + The specification of this material is given below.
668 + .DS
669 + mod WGMDfunc id
670 + 13+ rs_mod  rs  rs_urough rs_vrough
671 +    ts_mod  ts  ts_urough ts_vrough
672 +    td_mod
673 +    ux uy uz  funcfile  transform
674 + 0
675 + 9+  rfdif gfdif bfdif
676 +    rbdif gbdif bbdif
677 +    rtdif gtdif btdif
678 +    A10 ..
679 + .DE
680 + The sum of specular reflectance (
681 + .I rs
682 + ), specular transmittance (
683 + .I ts
684 + ), diffuse reflectance (
685 + .I "rfdif gfdif bfdif"
686 + for front and
687 + .I "rbdif gbdif bbdif"
688 + for back)
689 + and diffuse transmittance (
690 + .I "rtdif gtdif btdif"
691 + ) should be less than 1 for each
692 + channel.
693 + .PP
694 + Unique to this material, separate modifier channels are
695 + provided for each component.
696 + The main modifier is used on the diffuse reflectance, both
697 + front and back.
698 + The
699 + .I rs_mod
700 + modifier is used for specular reflectance.
701 + If "void" is given for
702 + .I rs_mod,
703 + then the specular reflection color will be white.
704 + The special "inherit" keyword may also be given, in which case
705 + specular reflectance will share the main modifier.
706 + This behavior is replicated for the specular transmittance modifier
707 + .I ts_mod,
708 + which has its own independent roughness expressions.
709 + Finally, the diffuse transmittance modifier is given as
710 + .I td_mod,
711 + which may also be "void" or "inherit".
712 + Note that any spectra or color for specular components must be
713 + carried by the named modifier(s).
714 + .PP
715 + The main advantage to this material over BRTDfunc and
716 + other programmable types described below is that the specular sampling is
717 + well-defined, so that all components are fully computed.
718 + .LP
719   .UL Dielectric
720   .PP
721   A dielectric material is transparent, and it refracts light
# Line 849 | Line 959 | mod transdata id
959   6+ red green blue rspec trans tspec A7 ..
960   .DE
961   .LP
962 + .UL BSDF
963 + .PP
964 + The BSDF material type loads an XML (eXtensible Markup Language)
965 + file describing a bidirectional scattering distribution function.
966 + Real arguments to this material may define additional
967 + diffuse components that augment the BSDF data.
968 + String arguments are used to define thickness for proxied
969 + surfaces and the "up" orientation for the material.
970 + .DS
971 + mod BSDF id
972 + 6+ thick BSDFfile ux uy uz funcfile transform
973 + 0
974 + 0|3|6|9
975 +     rfdif gfdif bfdif
976 +     rbdif gbdif bbdif
977 +     rtdif gtdif btdif
978 + .DE
979 + The first string argument is a "thickness" parameter that may be used
980 + to hide detail geometry being proxied by an aggregate BSDF material.
981 + If a view or shadow ray hits a BSDF proxy with non-zero thickness,
982 + it will pass directly through as if the surface were not there.
983 + Similar to the illum type, this permits direct viewing and
984 + shadow testing of complex geometry.
985 + The BSDF is used when a scattered (indirect) ray hits the surface,
986 + and any transmitted sample rays will be offset by the thickness amount
987 + to avoid the hidden geometry and gather samples from the other side.
988 + In this manner, BSDF surfaces can improve the results for indirect
989 + scattering from complex systems without sacrificing appearance or
990 + shadow accuracy.
991 + If the BSDF has transmission and back-side reflection data,
992 + a parallel BSDF surface may be
993 + placed slightly less than the given thickness away from the front surface
994 + to enclose the complex geometry on both sides.
995 + The sign of the thickness is important, as it indicates whether the
996 + proxied geometry is behind the BSDF surface (when thickness is positive)
997 + or in front (when thickness is negative).
998 + .LP
999 + The second string argument is the name of the BSDF file, which is
1000 + found in the usual auxiliary locations.
1001 + The following three string parameters name variables for an "up" vector,
1002 + which together with the surface normal, define the
1003 + local coordinate system that orients the BSDF.
1004 + These variables, along with the thickness, are defined in a function
1005 + file given as the next string argument.
1006 + An optional transform is used to scale the thickness and reorient the up vector.
1007 + .LP
1008 + If no real arguments are given, the BSDF is used by itself to determine
1009 + reflection and transmission.
1010 + If there are at least 3 real arguments, the first triplet is an
1011 + additional diffuse reflectance for the front side.
1012 + At least 6 real arguments adds diffuse reflectance to the rear side of the surface.
1013 + If there are 9 real arguments, the final triplet will be taken as an additional
1014 + diffuse transmittance.
1015 + All diffuse components as well as the non-diffuse transmission are
1016 + modified by patterns applied to this material.
1017 + The non-diffuse reflection from either side are unaffected.
1018 + Textures perturb the effective surface normal in the usual way.
1019 + .LP
1020 + The surface normal of this type is not altered to face the incoming ray,
1021 + so the front and back BSDF reflections may differ.
1022 + (Transmission is identical front-to-back by physical law.)\0
1023 + If back visibility is turned off during rendering and there is no
1024 + transmission or back-side reflection, only then the surface will be
1025 + invisible from behind.
1026 + Unlike other data-driven material types, the BSDF type is fully
1027 + supported and all parts of the distribution are properly sampled.
1028 + .LP
1029 + .UL aBSDF
1030 + .PP
1031 + The aBSDF material is identical to the BSDF type with two important
1032 + differences.
1033 + First, proxy geometry is not supported, so there is no thickness parameter.
1034 + Second, an aBSDF is assumed to have some specular through component
1035 + (the 'a' stands for "aperture"), which
1036 + is treated specially during the direct calculation and when viewing the
1037 + material.
1038 + Based on the BSDF data, the coefficient of specular transmission is
1039 + determined and used for modifying unscattered shadow and view rays.
1040 + .DS
1041 + mod aBSDF id
1042 + 5+ BSDFfile ux uy uz funcfile transform
1043 + 0
1044 + 0|3|6|9
1045 +     rfdif gfdif bfdif
1046 +     rbdif gbdif bbdif
1047 +     rtdif gtdif btdif
1048 + .DE
1049 + .LP
1050 + If a material has no specular transmitted component, it is much better
1051 + to use the BSDF type with a zero thickness than to use aBSDF.
1052 + .LP
1053   .UL Antimatter
1054   .PP
1055   Antimatter is a material that can "subtract" volumes from other volumes.
# Line 863 | Line 1064 | N mod1 mod2 .. modN
1064   The first modifier will also be used to shade the area leaving the
1065   antimatter volume and entering the regular volume.
1066   If mod1 is void, the antimatter volume is completely invisible.
1067 < Antimatter does not work properly with the material type "trans",
1068 < and multiple antimatter surfaces should be disjoint.
1067 > If shading is desired at antimatter surfaces, it is important
1068 > that the related volumes are closed with outward-facing normals.
1069 > Antimatter surfaces should not intersect with other antimatter boundaries,
1070 > and it is unwise to use the same modifier in nested antimatter volumes.
1071   The viewpoint must be outside all volumes concerned for a correct
1072   rendering.
1073   .NH 3
# Line 1068 | Line 1271 | A section of text meant to depict a picture, perhaps u
1271   font such as hexbit4x1.fnt, calls for uniform spacing.
1272   Reasonable magnitudes for proportional spacing are
1273   between 0.1 (for tightly spaced characters) and 0.3 (for wide spacing).
1274 + .LP
1275 + .UL Spectrum
1276 + .PP
1277 + The spectrum primitive is the most basic type for introducing spectral
1278 + color to a material.
1279 + Since materials only provide RGB parameters, spectral patterns
1280 + are the only way to superimpose wavelength-dependent behavior.
1281 + .DS
1282 + mod spectrum id
1283 + 0
1284 + 0
1285 + 5+ nmA nmB s1 s2 .. sN
1286 + .DE
1287 + The first two real arguments indicate the extrema of the
1288 + spectral range in nanometers.
1289 + Subsequent real values correspond to multipliers at each wavelength.
1290 + The nmA wavelength may be greater or less than nmB,
1291 + but they may not be equal, and their ordering matches
1292 + the order of the spectral values.
1293 + A minimum of 3 values must be given, which would act
1294 + more or less the same as a constant RGB multiplier.
1295 + As with RGB values, spectral quantities normally range between 0
1296 + and 1 at each wavelength, or average to 1.0 against a standard
1297 + sensitivity functions such as V(lambda).
1298 + The best results obtain when the spectral range and number
1299 + of samples match rendering options, though resampling will handle
1300 + any differences, zero-filling wavelenths outside the nmA to nmB
1301 + range.
1302 + A warning will be issued if the given wavelength range does not
1303 + adequately cover the visible spectrum.
1304 + .LP
1305 + .UL Specfile
1306 + .PP
1307 + The specfile primitive is equivalent to the spectrum type, but
1308 + the wavelength range and values are contained in a 1-dimensional
1309 + data file.
1310 + This may be a more convenient way to specify a spectral color,
1311 + especially one corresponding to a standard illuminant such as D65
1312 + or a library of measured spectra.
1313 + .DS
1314 + mod specfile id
1315 + 1 datafile
1316 + 0
1317 + 0
1318 + .DE
1319 + As with the spectrum type, rendering wavelengths outside the defined
1320 + range will be zero-filled.
1321 + Unlike the spectrum type, the file may contain non-uniform samples.
1322 + .LP
1323 + .UL Specfunc
1324 + .PP
1325 + The specfunc primitive offers dynamic control over a spectral
1326 + pattern, similar to the colorfunc type.
1327 + .DS
1328 + mod specfunc id
1329 + 2+ sfunc funcfile transform
1330 + 0
1331 + 2+ nmA nmB A3 ..
1332 + .DE
1333 + Like the spectrum primitive, the wavelength range is specified
1334 + in the first two real arguments, and additional real values are
1335 + set in the evaluation context.
1336 + This function is fed a wavelenth sample
1337 + between nmA and nmB as its only argument,
1338 + and it returns the corresponding spectral intensity.
1339 + .LP
1340 + .UL Specdata
1341 + .PP
1342 + Specdata is like brightdata and colordata, but with more
1343 + than 3 specular samples.
1344 + .DS
1345 + mod specdata id
1346 + 3+n+
1347 +        func datafile
1348 +        funcfile x1 x2 .. xn transform
1349 + 0
1350 + m A1 A2 .. Am
1351 + .DE
1352 + The data file must have one more dimension than the coordinate
1353 + variable count, as this final dimension corresponds to the covered
1354 + spectrum.
1355 + The starting and ending wavelengths are specified in "datafile"
1356 + as well as the number of spectral samples.
1357 + The function "func" will be called with two parameters, the
1358 + interpolated spectral value for the current coordinate and the
1359 + associated wavelength.
1360 + If the spectrum is broken into 12 components, then 12 calls
1361 + will be made to "func" for the relevant ray evaluation.
1362 + .LP
1363 + .UL Specpict
1364 + .PP
1365 + Specpict is a special case of specdata, where the pattern is
1366 + a hyperspectral image stored in the common-exponent file format.
1367 + The dimensions of the image data are determined by the picture
1368 + just as with the colorpict primitive.
1369 + .DS
1370 + mod specpict id
1371 + 5+
1372 +        func specfile
1373 +        funcfile u v transform
1374 + 0
1375 + m A1 A2 .. Am
1376 + .DE
1377 + The function "func" is called with the interpolated pixel value
1378 + and the wavelength sample in nanometers, the same as specdata,
1379 + with as many calls made as there are components in "specfile".
1380   .NH 3
1381   Mixtures
1382   .PP
1383   A mixture is a blend of one or more materials or textures and patterns.
1384 + Blended materials should not be light source types or virtual source types.
1385   The basic types are given below.
1386   .LP
1387   .UL Mixfunc
# Line 1093 | Line 1403 | which serves as a form of opacity control when used wi
1403   Vname is the coefficient defined in funcfile that determines the influence
1404   of foreground.
1405   The background coefficient is always (1-vname).
1096 – Since the references are not resolved until runtime, the last
1097 – definitions of the modifier id's will be used.
1098 – This can result in modifier loops, which are detected by the
1099 – renderer.
1406   .LP
1407   .UL Mixdata
1408   .PP
# Line 1197 | Line 1503 | and they are listed in the file
1503   The following variables are particularly important:
1504   .DS
1505          Dx, Dy, Dz              - incident ray direction
1200 –        Px, Py, Pz              - intersection point
1506          Nx, Ny, Nz              - surface normal at intersection point
1507 +        Px, Py, Pz              - intersection point
1508 +        T                       - distance from start
1509 +        Ts                      - single ray (shadow) distance
1510          Rdot                    - cosine between ray and normal
1511          arg(0)                  - number of real arguments
1512          arg(i)                  - i'th real argument
1513   .DE
1514 + For mesh objects, the local surface coordinates are available:
1515 + .DS
1516 +        Lu, Lv                  - local (u,v) coordinates
1517 + .DE
1518   For BRDF types, the following variables are defined as well:
1519   .DS
1520          NxP, NyP, NzP           - perturbed surface normal
# Line 1217 | Line 1529 | If no file is needed by a given primitive because all
1529   variables are global, a period (`.') can be given in
1530   place of the file name.
1531   It is also possible to give an expression instead of a straight
1532 < variable name in a scene file, although such expressions should
1533 < be kept simple as they cannot contain any white space.
1222 < Also, functions (requiring parameters)
1532 > variable name in a scene file.
1533 > Functions (requiring parameters)
1534   must be given as names and not as expressions.
1535   .PP
1536   Constant expressions are used as an optimization in function
# Line 1383 | Line 1694 | converts a picture to and from simpler formats.
1694   Pictures may be displayed directly under X11 using the program
1695   .I ximage,
1696   or converted a standard image format.
1697 < .I Ra_avs
1698 < converts to and from AVS image format.
1388 < .I Ra_pict
1389 < converts to Macintosh 32-bit PICT2 format.
1697 > .I Ra_bmp
1698 > converts to and from Microsoft Bitmap images.
1699   .I Ra_ppm
1700   converts to and from Poskanzer Portable Pixmap formats.
1392 – .I Ra_pr
1393 – converts to and from Sun 8-bit rasterfile format.
1394 – .I Ra_pr24
1395 – converts to and from Sun 24-bit rasterfile format.
1701   .I Ra_ps
1702   converts to PostScript color and greyscale formats.
1703   .I Ra_rgbe
# Line 1408 | Line 1713 | converts to and from Radiance CIE picture format.
1713   .NH 1
1714   License
1715   .PP
1716 < Radiance is a registered copyright of The Regents of the University of
1717 < California ("The Regents"). The Regents grant to you a nonexclusive,
1718 < nontransferable license ("License") to use Radiance source code without fee.
1719 < You may not sell or distribute Radiance to others without the prior express
1720 < written permission of The Regents.
1721 < You may compile and use this software on any machines to which you have
1722 < personal access, and may share its use with others who have access to the
1723 < same machines.
1724 < .PP
1725 < NEITHER THE UNITED STATES NOR THE UNITED STATES DEPARTMENT OF ENERGY, NOR ANY
1726 < OF THEIR EMPLOYEES, MAKES ANY WARRANTY, EXPRESS OR IMPLIED, OR ASSUMES ANY
1727 < LEGAL LIABILITY OR RESPONSIBILITY FOR THE ACCURACY, COMPLETENESS, OR
1728 < USEFULNESS OF ANY INFORMATION, APPARATUS, PRODUCT, OR PROCESS DISCLOSED, OR
1729 < REPRESENTS THAT ITS USE WOULD NOT INFRINGE PRIVATELY OWNED RIGHTS.
1730 < By downloading, using or copying this software, you agree to abide by the
1731 < intellectual property laws and all other applicable laws of the United
1732 < States, and by the terms of this License Agreement. Ownership of the software
1733 < shall remain solely in The Regents.
1734 < The Regents shall have the right to terminate this License immediately by
1735 < written notice upon your breach of, or noncompliance with, any of its terms.
1736 < You shall be liable for any infringement or damages resulting from your
1737 < failure to abide by the terms of this License Agreement.
1738 < .PP
1739 < NOTICE: The Government is granted for itself and others acting on its behalf
1740 < a paid-up, nonexclusive irrevocable worldwide license in this data to
1741 < reproduce, prepare derivative works, and perform publicly and display
1742 < publicly. Beginning five (5) years after permission to assert copyright is
1743 < granted, subject to two possible five year renewals, the Government is
1744 < granted for itself and others acting on its behalf a paid-up, non-exclusive,
1745 < irrevocable worldwide license in this data to reproduce, prepare derivative
1746 < works, distribute copies to the public, perform publicly and display
1747 < publicly, and to permit others to do so.
1716 > .DS
1717 > The Radiance Software License, Version 1.0
1718 >
1719 > Copyright (c) 1990 - 2008 The Regents of the University of California,
1720 > through Lawrence Berkeley National Laboratory.   All rights reserved.
1721 >
1722 > Redistribution and use in source and binary forms, with or without
1723 > modification, are permitted provided that the following conditions
1724 > are met:
1725 >
1726 > 1. Redistributions of source code must retain the above copyright
1727 >        notice, this list of conditions and the following disclaimer.
1728 >
1729 > 2. Redistributions in binary form must reproduce the above copyright
1730 >      notice, this list of conditions and the following disclaimer in
1731 >      the documentation and/or other materials provided with the
1732 >      distribution.
1733 >
1734 > 3. The end-user documentation included with the redistribution,
1735 >          if any, must include the following acknowledgment:
1736 >            "This product includes Radiance software
1737 >                (http://radsite.lbl.gov/)
1738 >                developed by the Lawrence Berkeley National Laboratory
1739 >              (http://www.lbl.gov/)."
1740 >      Alternately, this acknowledgment may appear in the software itself,
1741 >      if and wherever such third-party acknowledgments normally appear.
1742 >
1743 > 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
1744 >      and "The Regents of the University of California" must
1745 >      not be used to endorse or promote products derived from this
1746 >      software without prior written permission. For written
1747 >      permission, please contact [email protected].
1748 >
1749 > 5. Products derived from this software may not be called "Radiance",
1750 >      nor may "Radiance" appear in their name, without prior written
1751 >      permission of Lawrence Berkeley National Laboratory.
1752 >
1753 > THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
1754 > WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
1755 > OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
1756 > DISCLAIMED.   IN NO EVENT SHALL Lawrence Berkeley National Laboratory OR
1757 > ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
1758 > SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
1759 > LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
1760 > USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
1761 > ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
1762 > OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
1763 > OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
1764 > SUCH DAMAGE.
1765 > .DE
1766   .NH 1
1767   Acknowledgements
1768   .PP
# Line 1455 | Line 1778 | the Ecole Polytechnique Federale de Lausanne (EPFL Uni
1778   in Lausanne, Switzerland.
1779   .NH 1
1780   References
1781 + .LP
1782 + Ward, Gregory J., Bruno Bueno, David Geisler-Moroder,
1783 + Lars O. Grobe, Jacob C. Jonsson, Eleanor
1784 + S. Lee, Taoning Wang, Helen Rose Wilson,
1785 + ``Daylight Simulation Workflows Incorporating
1786 + Measured Bidirectional Scattering Distribution Functions,''
1787 + .I "Energy & Buildings",
1788 + Vol. 259, No. 111890, 2022.
1789 + .LP
1790 + Wang, Taoning, Gregory Ward, Eleanor Lee,
1791 + ``Efficient modeling of optically-complex, non-coplanar
1792 + exterior shading: Validation of matrix algebraic methods,''
1793 + .I "Energy & Buildings",
1794 + vol. 174, pp. 464-83, Sept. 2018.
1795 + .LP
1796 + Lee, Eleanor S., David Geisler-Moroder, Gregory Ward,
1797 + ``Modeling the direct sun component in buildings using matrix
1798 + algebraic approaches: Methods and validation,''
1799 + .I Solar Energy,
1800 + vol. 160, 15 January 2018, pp 380-395.
1801 + .LP
1802 + Ward, G., M. Kurt & N. Bonneel,
1803 + ``Reducing Anisotropic BSDF Measurement to Common Practice,''
1804 + .I Workshop on Material Appearance Modeling,
1805 + 2014.
1806 + .LP
1807 + McNeil, A., C.J. Jonsson, D. Appelfeld, G. Ward, E.S. Lee,
1808 + ``A validation of a ray-tracing tool used to generate
1809 + bi-directional scattering distribution functions for
1810 + complex fenestration systems,''
1811 + .I "Solar Energy",
1812 + 98, 404-14, November 2013.
1813 + .LP
1814 + Ward, G., R. Mistrick, E.S. Lee, A. McNeil, J. Jonsson,
1815 + ``Simulating the Daylight Performance of Complex Fenestration Systems
1816 + Using Bidirectional Scattering Distribution Functions within Radiance,''
1817 + .I "Leukos",
1818 + 7(4),
1819 + April 2011.
1820 + .LP
1821 + Cater, K., A. Chalmers, G. Ward,
1822 + ``Detail to Attention: Exploiting Visual Tasks for Selective Rendering,''
1823 + .I "Eurograhics Symposium on Rendering",
1824 + June 2003.
1825 + .LP
1826 + Ward, G., Elena Eydelberg-Vileshin,
1827 + ``Picture Perfect RGB Rendering Using Spectral Prefiltering and
1828 + Sharp Color Primaries,''
1829 + 13th Eurographics Workshop on Rendering, P. Debevec and
1830 + S. Gibson (Editors), June 2002.
1831 + .LP
1832 + Ward, G. and M. Simmons,
1833 + ``The Holodeck Ray Cache: An Interactive Rendering System for Global
1834 + Illumination in Nondiffuse Environments,''
1835 + .I "ACM Transactions on Graphics,"
1836 + 18(4):361-98, October 1999.
1837 + .LP
1838 + Larson, G.W., H. Rushmeier, C. Piatko,
1839 + ``A Visibility Matching Tone Reproduction Operator for High Dynamic
1840 + Range Scenes,''
1841 + .I "IEEE Transactions on Visualization and Computer Graphics",
1842 + 3(4), 291-306, December 1997.
1843 + .LP
1844 + Ward, G.,
1845 + ``Making Global Illumination User Friendly,''
1846 + .I "Sixth Eurographics Workshop on Rendering",
1847 + proceedings to be published by Springer-Verlag,
1848 + Dublin, Ireland, June 1995.
1849 + .LP
1850 + Rushmeier, H., G. Ward, C. Piatko, P. Sanders, B. Rust,
1851 + ``Comparing Real and Synthetic Images: Some Ideas about Metrics,''
1852 + .I "Sixth Eurographics Workshop on Rendering",
1853 + proceedings to be published by Springer-Verlag,
1854 + Dublin, Ireland, June 1995.
1855   .LP
1856   Ward, G.,
1857   ``The Radiance Lighting Simulation and Rendering System,''

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