--- ray/doc/ray.html 2023/05/11 17:18:39 1.31 +++ ray/doc/ray.html 2023/11/15 18:28:10 1.33 @@ -1,8 +1,8 @@ - + -The RADIANCE 5.4 Synthetic Imaging System +The RADIANCE 6.0 Synthetic Imaging System @@ -10,7 +10,7 @@ The RADIANCE 5.4 Synthetic Imaging System

-The RADIANCE 5.4 Synthetic Imaging System +The RADIANCE 6.0 Synthetic Imaging System

@@ -1461,6 +1461,100 @@ or: A section of text meant to depict a picture, perhaps using a special purpose font such as hexbit4x1.fnt, calls for uniform spacing. Reasonable magnitudes for proportional spacing are between 0.1 (for tightly spaced characters) and 0.3 (for wide spacing). +

+ +

+ + Spectrum + + +
+ The spectrum primitive is the most basic type for introducing spectral + color to a material. + Since materials only provide RGB parameters, spectral patterns + are the only way to superimpose wavelength-dependent behavior. + +
+        mod spectrum id
+	0
+	0
+	5+ nmA nmB s1 s2 .. sN
+
+ +

+ The first two real arguments indicate the limits of the covered + spectral range in nanometers. + Subsequent real values correspond to multipliers in each wavelength band, + where the first band goes from nmA to nmA+(nmB-nmA)/N, and N is the + number of bands (i.e., the number of real arguments minus 2). + The nmA wavelength may be greater or less than the nmB wavelength, + but they may not be equal, and their ordering must correspond to + the ordering of the spectral values. + A minimum of 3 values must be given, which would act + more or less the same as a constant RGB multiplier. + As with RGB values, spectral quantities normally range between 0 + and 1 at each wavelength, or average to 1.0 against a standard + sensitivity functions such as V(lambda). + The best results obtain when the spectral range and number + of samples match rendering options, though resampling will handle + any differences, zero-filling wavelenths outside the nmA to nmB + range. + A warning will be issued if the given wavelength range does not + adequately cover the visible spectrum. + +

+ +

+ + Specfile + + +
+ The specfile primitive is equivalent to the spectrum type, but + the wavelength range and values are contained in a 1-dimensional + data file. + This may be a more convenient way to specify a spectral color, + especially one corresponding to a standard illuminant such as D65 + or a library of measured spectra. + +
+        mod specfile id
+	1 datafile
+	0
+	0
+
+ +

+ As with the spectrum type, rendering wavelengths outside the defined + range will be zero-filled. + Unlike the spectrum type, the file may contain non-uniform samples. + +

+ +

+ + Specfunc + + +
+ The specfunc primitive offers dynamic control over a spectral + pattern, similar to the colorfunc type. + +
+        mod specfunc id
+	2+ sval funcfile transform
+	0
+	2+ nmA nmB A3 ..
+
+ +

+ Like the spectrum primitive, the wavelength range is specified + in the first two real arguments, and additional real values are + accessible to the sval function. + This function is fed a wavelenth sample + between nmA and nmB as its only argument, + and it returns the corresponding spectral intensity. +

@@ -1947,6 +2041,13 @@ Ecole Polytechnique Federale de Lausanne (EPFL Unive