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+++ ray/doc/ray.html 2023/12/13 23:26:16 1.38
@@ -1,5 +1,5 @@
-
+
The RADIANCE 6.0 Synthetic Imaging System
@@ -1552,6 +1552,61 @@ or:
This function is fed a wavelenth sample
between nmA and nmB as its only argument,
and it returns the corresponding spectral intensity.
+
+<dt>
+ <a NAME="Specdata">
+ <b>Specdata</b>
+ </a>
+
+<dd>
+ Specdata is like brightdata and colordata, but with more
+ than 3 specular samples.
+
+<pre>
+ mod specdata id
+ 3+n+
+ func datafile
+ funcfile x1 x2 .. xn transform
+ 0
+ m A1 A2 .. Am
+</pre>
+
+<p>
+ The data file must have one more dimension than the coordinate
+ variable count, as this final dimension corresponds to the covered
+ spectrum.
+ The starting and ending wavelengths are specified in "datafile"
+ as well as the number of spectral samples.
+ The function "func" will be called with two parameters, the
+ interpolated spectral value for the current coordinate and the
+ associated wavelength.
+ If the spectrum is broken into 12 components, then 12 calls
+ will be made to "func" for the relevant ray evaluation.
+
+<dt>
+ <a NAME="Specpict">
+ <b>Specpict</b>
+ </a>
+
+<dd>
+ Specpict is a special case of specdata, where the pattern is
+ a hyperspectral image stored in the common-exponent file format.
+ The dimensions of the image data are determined by the picture
+ just as with the colorpict primitive.
+
+<pre>
+ mod specpict id
+ 5+
+ func specfile
+ funcfile u v transform
+ 0
+ m A1 A2 .. Am
+</pre>
+
+<p>
+ The function "func" is called with the interpolated pixel value
+ and the wavelength sample in nanometers, the same as specdata,
+ with as many calls made as there are components in "specfile".
</dl>