[ViewVC] Diff of: Development/ray/doc/ray.1

Comparing ray/doc/ray.1 (file contents):
Revision 1.20 by greg, Tue Jun 21 23:58:00 2011 UTC vs.
Revision 1.41 by greg, Wed Nov 15 18:28:09 2023 UTC

-<
+.\" RCSid "$Id"
->
+.\" RCSid "$Id$"
+.\" Print using the -ms macro package
-<
+.DA 2/17/2011
->
+.DA 11/13/2023
+.LP
-<
+.tl """Copyright \(co 2011 Regents, University of California
->
+.tl """Copyright \(co 2023 Regents, University of California
+.sp 2
+.TL
+The
+red green blue spec urough vrough trans tspec
+.DE
+.LP
-+
+.UL Ashik2
-+
+.PP
-+
+Ashik2 is the anisotropic reflectance model by Ashikhmin & Shirley.
-+
+The string arguments are the same as for plastic2, but the real
-+
+arguments have additional flexibility to specify the specular color.
-+
+Also, rather than roughness, specular power is used, which has no
-+
+physical meaning other than larger numbers are equivalent to a smoother
-+
+surface.
-+
+Unlike other material types, total reflectance is the sum of
-+
+diffuse and specular colors, and should be adjusted accordingly.
-+
+.DS
-+
+mod ashik2 id
-+
++ ux uy uz funcfile transform
-+
-+
+dred dgrn dblu sred sgrn sblu u-power v-power
-+
+.DE
-+
+.LP
+.UL Dielectric
+.PP
+A dielectric material is transparent, and it refracts light
+placed slightly less than the given thickness away from the front surface
+to enclose the complex geometry on both sides.
+The sign of the thickness is important, as it indicates whether the
-<
+proxied geometry is behind the.
-<
+.I BSDF
-<
+surface (when thickness is positive)
->
+proxied geometry is behind the BSDF surface (when thickness is positive)
+or in front (when thickness is negative).
+.LP
+The second string argument is the name of the BSDF file, which is
+Unlike other data-driven material types, the BSDF type is fully
+supported and all parts of the distribution are properly sampled.
+.LP
-+
+.UL aBSDF
-+
+.PP
-+
+The aBSDF material is identical to the BSDF type with two important
-+
+differences.
-+
+First, proxy geometry is not supported, so there is no thickness parameter.
-+
+Second, an aBSDF is assumed to have some specular through component
-+
+(the 'a' stands for "aperture"), which
-+
+is treated specially during the direct calculation and when viewing the
-+
+material.
-+
+Based on the BSDF data, the coefficient of specular transmission is
-+
+determined and used for modifying unscattered shadow and view rays.
-+
+.DS
-+
+mod aBSDF id
-+
++ BSDFfile ux uy uz funcfile transform
-+
-+
+|3|6|9
-+
+     rfdif gfdif bfdif
-+
+     rbdif gbdif bbdif
-+
+     rtdif gtdif btdif
-+
+.DE
-+
+.LP
-+
+If a material has no specular transmitted component, it is much better
-+
+to use the BSDF type with a zero thickness than to use aBSDF.
-+
+.LP
+.UL Antimatter
+.PP
+Antimatter is a material that can "subtract" volumes from other volumes.
+The first modifier will also be used to shade the area leaving the
+antimatter volume and entering the regular volume.
+If mod1 is void, the antimatter volume is completely invisible.
-<
+Antimatter does not work properly with the material type "trans",
-<
+and multiple antimatter surfaces should be disjoint.
->
+If shading is desired at antimatter surfaces, it is important
->
+that the related volumes are closed with outward-facing normals.
->
+Antimatter surfaces should not intersect with other antimatter boundaries,
->
+and it is unwise to use the same modifier in nested antimatter volumes.
+The viewpoint must be outside all volumes concerned for a correct
+rendering.
+.NH 3
+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).
-+
+.LP
-+
+.UL Spectrum
-+
+.PP
-+
+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.
-+
+.DS
-+
+mod spectrum id
-+
-+
-+
++ nmA nmB s1 s2 .. sN
-+
+.DE
-+
+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.
-+
+.LP
-+
+.UL Specfile
-+
+.PP
-+
+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.
-+
+.DS
-+
+mod specfile id
-+
+datafile
-+
-+
-+
+.DE
-+
+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.
-+
+.LP
-+
+.UL Specfunc
-+
+.PP
-+
+The specfunc primitive offers dynamic control over a spectral
-+
+pattern, similar to the colorfunc type.
-+
+.DS
-+
+mod specfunc id
-+
++ sval funcfile transform
-+
-+
++ nmA nmB A3 ..
-+
+.DE
-+
+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.
+.NH 3
+Mixtures
+.PP
+A mixture is a blend of one or more materials or textures and patterns.
-+
+Blended materials should not be light source types or virtual source types.
+The basic types are given below.
+.LP
+.UL Mixfunc
+in Lausanne, Switzerland.
+.NH 1
+References
-+
+.LP
-+
+Ward, Gregory J., Bruno Bueno, David Geisler-Moroder,
-+
+Lars O. Grobe, Jacob C. Jonsson, Eleanor
-+
+S. Lee, Taoning Wang, Helen Rose Wilson,
-+
+``Daylight Simulation Workflows Incorporating
-+
+Measured Bidirectional Scattering Distribution Functions,''
-+
+.I "Energy & Buildings",
-+
+Vol. 259, No. 111890, 2022.
-+
+.LP
-+
+Wang, Taoning, Gregory Ward, Eleanor Lee,
-+
+``Efficient modeling of optically-complex, non-coplanar
-+
+exterior shading: Validation of matrix algebraic methods,''
-+
+.I "Energy & Buildings",
-+
+vol. 174, pp. 464-83, Sept. 2018.
-+
+.LP
-+
+Lee, Eleanor S., David Geisler-Moroder, Gregory Ward,
-+
+``Modeling the direct sun component in buildings using matrix
-+
+algebraic approaches: Methods and validation,''
-+
+.I Solar Energy,
-+
+vol. 160, 15 January 2018, pp 380-395.
-+
+.LP
-+
+Ward, G., M. Kurt & N. Bonneel,
-+
+``Reducing Anisotropic BSDF Measurement to Common Practice,''
-+
+.I Workshop on Material Appearance Modeling,
-+
+.
-+
+.LP
-+
+McNeil, A., C.J. Jonsson, D. Appelfeld, G. Ward, E.S. Lee,
-+
+``A validation of a ray-tracing tool used to generate
-+
+bi-directional scattering distribution functions for
-+
+complex fenestration systems,''
-+
+.I "Solar Energy",
-+
+, 404-14, November 2013.
-+
+.LP
-+
+Ward, G., R. Mistrick, E.S. Lee, A. McNeil, J. Jonsson,
-+
+``Simulating the Daylight Performance of Complex Fenestration Systems
-+
+Using Bidirectional Scattering Distribution Functions within Radiance,''
-+
+.I "Leukos",
-+
+(4),
-+
+April 2011.
+.LP
+Cater, K., A. Chalmers, G. Ward,
+``Detail to Attention: Exploiting Visual Tasks for Selective Rendering,''

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Comparing ray/doc/ray.1 (file contents): Revision 1.20 by greg, Tue Jun 21 23:58:00 2011 UTC vs. Revision 1.41 by greg, Wed Nov 15 18:28:09 2023 UTC

Diff Legend

Comparing ray/doc/ray.1 (file contents):
Revision 1.20 by greg, Tue Jun 21 23:58:00 2011 UTC vs.
Revision 1.41 by greg, Wed Nov 15 18:28:09 2023 UTC