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<head> |
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<title> |
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The RADIANCE 5.2 Synthetic Imaging System |
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The RADIANCE 6.0 Synthetic Imaging System |
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</title> |
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</head> |
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<body> |
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<p> |
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<h1> |
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The RADIANCE 5.2 Synthetic Imaging System |
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The RADIANCE 6.0 Synthetic Imaging System |
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</h1> |
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|
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<p> |
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(ovals). |
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The central program is <i>rpict</i>, which produces a picture from a scene |
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description. |
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<i>Rview</i> is a variation of rpict that computes and displays images |
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<i>Rvu</i> is a variation of rpict that computes and displays images |
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interactively, and rtrace computes single ray values. |
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Other programs (not shown) connect many of these elements together, |
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such as the executive programs |
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Also, rather than roughness, specular power is used, which has no |
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physical meaning other than larger numbers are equivalent to a smoother |
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surface. |
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Unlike other material types, total reflectance is the sum of |
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diffuse and specular colors, and should be adjusted accordingly. |
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<pre> |
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mod ashik2 id |
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4+ ux uy uz funcfile transform |
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<p> |
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<dt> |
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<a NAME="WGMDfunc"> |
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<b>WGMDfunc</b> |
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</a> |
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|
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<dd> |
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WGMDfunc is a more programmable version of <a HREF="#Trans2">trans2</a>, |
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with separate modifier paths and variables to control each component. |
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(WGMD stands for Ward-Geisler-Moroder-Duer, which is the basis for |
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this empirical model, similar to previous ones beside Ashik2.) |
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The specification of this material is given below. |
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<pre> |
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mod WGMDfunc id |
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13+ rs_mod rs rs_urough rs_vrough |
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ts_mod ts ts_urough ts_vrough |
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td_mod |
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ux uy uz funcfile transform |
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0 |
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9+ rfdif gfdif bfdif |
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rbdif gbdif bbdif |
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rtdif gtdif btdif |
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A10 .. |
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</pre> |
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|
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The sum of specular reflectance (<I>rs</I>), specular transmittance (<I>ts</I>), |
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diffuse reflectance (<I>rfdif gfdif bfdif</I> for front and <I>rbdif gbdif bbdif</I> for back) |
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and diffuse transmittance (<I>rtdif gtdif btdif</I>) should be less than 1 for each |
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channel. |
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|
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<p> |
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|
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Unique to this material, separate modifier channels are |
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provided for each component. |
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The main modifier is used on the diffuse reflectance, both |
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front and back. |
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The <I>rs_mod</I> modifier is used for specular reflectance. |
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If "void" is given for <I>rs_mod</I>, |
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then the specular reflection color will be white. |
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The special "inherit" keyword may also be given, in which case |
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specular reflectance will share the main modifier. |
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This behavior is replicated for the specular transmittance modifier |
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<I>ts_mod</I>, which also has its own independent roughness expressions. |
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Finally, the diffuse transmittance modifier is given as |
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<I>td_mod</I>, which may also be "void" or "inherit". |
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Note that any spectra or color for specular components must be |
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carried by the named modifier(s). |
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|
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<p> |
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|
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The main advantage to this material over |
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<a HREF="#BRTDfunc">BRTDfunc</a> and |
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other programmable types described below is that the specular sampling is |
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well-defined, so that all components are fully computed. |
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|
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<p> |
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|
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<dt> |
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<a NAME="Dielectric"> |
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<b>Dielectric</b> |
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</a> |
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<p> |
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|
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<dt> |
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<a NAME="sBSDF"> |
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<b>sBSDF</b> |
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<a NAME="aBSDF"> |
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<b>aBSDF</b> |
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</a> |
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<dd> |
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The sBSDF material is identical to the BSDF type with two |
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The aBSDF material is identical to the BSDF type with two |
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important differences. First, proxy geometry is not |
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supported, so there is no thickness parameter. Second, an |
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sBSDF is assumed to have some specular through component, |
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aBSDF is assumed to have some specular through component |
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(the ’a’ stands for "aperture"), |
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which is treated specially during the direct calculation |
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and when viewing the material. Based on the BSDF data, the |
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coefficient of specular transmission is determined and used |
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for modifying unscattered shadow and view rays. |
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|
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<pre> |
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< |
mod sBSDF id |
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mod aBSDF id |
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5+ BSDFfile ux uy uz funcfile transform |
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0 |
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0|3|6|9 |
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<p> |
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If a material has no specular transmitted component, it is |
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much better to use the BSDF type with a zero thickness |
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than to use sBSDF. |
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than to use aBSDF. |
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<p> |
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|
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<dt> |
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A section of text meant to depict a picture, perhaps using a special purpose font such as hexbit4x1.fnt, calls for uniform spacing. |
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Reasonable magnitudes for proportional spacing are between 0.1 (for tightly spaced characters) and 0.3 (for wide spacing). |
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|
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<p> |
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|
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<dt> |
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<a NAME="Spectrum"> |
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<b>Spectrum</b> |
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</a> |
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|
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<dd> |
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The spectrum primitive is the most basic type for introducing spectral |
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color to a material. |
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Since materials only provide RGB parameters, spectral patterns |
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are the only way to superimpose wavelength-dependent behavior. |
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|
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<pre> |
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mod spectrum id |
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0 |
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0 |
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5+ nmA nmB s1 s2 .. sN |
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</pre> |
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|
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<p> |
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The first two real arguments indicate the extrema of the |
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spectral range in nanometers. |
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Subsequent real values correspond to multipliers at each wavelength. |
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The nmA wavelength may be greater or less than nmB, |
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but they may not be equal, and their ordering matches |
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the order of the spectral values. |
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A minimum of 3 values must be given, which would act |
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more or less the same as a constant RGB multiplier. |
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As with RGB values, spectral quantities normally range between 0 |
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and 1 at each wavelength, or average to 1.0 against a standard |
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sensitivity functions such as V(lambda). |
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The best results obtain when the spectral range and number |
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of samples match rendering options, though resampling will handle |
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any differences, zero-filling wavelenths outside the nmA to nmB |
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range. |
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A warning will be issued if the given wavelength range does not |
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adequately cover the visible spectrum. |
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|
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<p> |
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|
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<dt> |
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<a NAME="Specfile"> |
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<b>Specfile</b> |
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</a> |
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|
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<dd> |
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The specfile primitive is equivalent to the spectrum type, but |
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the wavelength range and values are contained in a 1-dimensional |
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data file. |
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This may be a more convenient way to specify a spectral color, |
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especially one corresponding to a standard illuminant such as D65 |
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or a library of measured spectra. |
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|
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<pre> |
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mod specfile id |
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1 datafile |
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0 |
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0 |
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</pre> |
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|
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<p> |
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As with the spectrum type, rendering wavelengths outside the defined |
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range will be zero-filled. |
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Unlike the spectrum type, the file may contain non-uniform samples. |
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|
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<p> |
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|
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<dt> |
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<a NAME="Specfunc"> |
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<b>Specfunc</b> |
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</a> |
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|
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<dd> |
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The specfunc primitive offers dynamic control over a spectral |
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pattern, similar to the colorfunc type. |
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|
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<pre> |
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mod specfunc id |
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2+ sfunc funcfile transform |
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0 |
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2+ nmA nmB A3 .. |
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</pre> |
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|
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<p> |
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Like the spectrum primitive, the wavelength range is specified |
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in the first two real arguments, and additional real values are |
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set in the evaluation context. |
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This function is fed a wavelenth sample |
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between nmA and nmB as its only argument, |
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and it returns the corresponding spectral intensity. |
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|
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<dt> |
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<a NAME="Specdata"> |
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<b>Specdata</b> |
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</a> |
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|
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<dd> |
| 1618 |
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Specdata is like brightdata and colordata, but with more |
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than 3 specular samples. |
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|
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<pre> |
| 1622 |
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mod specdata id |
| 1623 |
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3+n+ |
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func datafile |
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funcfile x1 x2 .. xn transform |
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0 |
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m A1 A2 .. Am |
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</pre> |
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|
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<p> |
| 1631 |
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The data file must have one more dimension than the coordinate |
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variable count, as this final dimension corresponds to the covered |
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spectrum. |
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The starting and ending wavelengths are specified in "datafile" |
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as well as the number of spectral samples. |
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The function "func" will be called with two parameters, the |
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interpolated spectral value for the current coordinate and the |
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associated wavelength. |
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If the spectrum is broken into 12 components, then 12 calls |
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will be made to "func" for the relevant ray evaluation. |
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|
| 1642 |
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<dt> |
| 1643 |
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<a NAME="Specpict"> |
| 1644 |
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<b>Specpict</b> |
| 1645 |
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</a> |
| 1646 |
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|
| 1647 |
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<dd> |
| 1648 |
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Specpict is a special case of specdata, where the pattern is |
| 1649 |
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a hyperspectral image stored in the common-exponent file format. |
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The dimensions of the image data are determined by the picture |
| 1651 |
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just as with the colorpict primitive. |
| 1652 |
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|
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<pre> |
| 1654 |
+ |
mod specpict id |
| 1655 |
+ |
5+ |
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func specfile |
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funcfile u v transform |
| 1658 |
+ |
0 |
| 1659 |
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m A1 A2 .. Am |
| 1660 |
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</pre> |
| 1661 |
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|
| 1662 |
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<p> |
| 1663 |
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The function "func" is called with the interpolated pixel value |
| 1664 |
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and the wavelength sample in nanometers, the same as specdata, |
| 1665 |
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with as many calls made as there are components in "specfile". |
| 1666 |
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|
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</dl> |
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|
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<p> |
| 2012 |
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directs the use of a scene description. |
| 2013 |
|
<ul> |
| 2014 |
|
<li> |
| 2015 |
< |
<a NAME="rvu" HREF="../man_html/rvu.1.html"><b>Rview</b></a> is ray-tracing program for viewing a scene interactively. |
| 2015 |
> |
<a NAME="rvu" HREF="../man_html/rvu.1.html"><b>Rvu</b></a> is ray-tracing program for viewing a scene interactively. |
| 2016 |
|
When the user specifies a new perspective, rvu quickly displays a rough image on the terminal, |
| 2017 |
|
then progressively increases the resolution as the user looks on. |
| 2018 |
|
He can select a particular section of the image to improve, or move to a different view and start over. |
| 2048 |
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or converted a standard image format using one of the following |
| 2049 |
|
<b>translators</b>: |
| 2050 |
|
<ul> |
| 2051 |
< |
<li> <a HREF="../man_html/ra_bmp.1.html"><b>Ra_bmp</b> |
| 2051 |
> |
<li> <a HREF="../man_html/ra_bmp.1.html"><b>Ra_bmp</b></a> |
| 2052 |
|
converts to and from BMP image format. |
| 2053 |
|
<li> <a HREF="../man_html/ra_ppm.1.html"><b>Ra_ppm</b></a> |
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converts to and from Poskanzer Portable Pixmap formats. |
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<pre> |
| 2078 |
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The Radiance Software License, Version 1.0 |
| 2079 |
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|
| 2080 |
< |
Copyright (c) 1990 - 2014 The Regents of the University of California, |
| 2080 |
> |
Copyright (c) 1990 - 2021 The Regents of the University of California, |
| 2081 |
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through Lawrence Berkeley National Laboratory. All rights reserved. |
| 2082 |
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|
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Redistribution and use in source and binary forms, with or without |
| 2150 |
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</h2> |
| 2151 |
|
<p> |
| 2152 |
|
<ul> |
| 2153 |
+ |
<li>Ward, Gregory J., Bruno Bueno, David Geisler-Moroder, |
| 2154 |
+ |
Lars O. Grobe, Jacob C. Jonsson, Eleanor |
| 2155 |
+ |
S. Lee, Taoning Wang, Helen Rose Wilson, |
| 2156 |
+ |
"<a href="https://doi.org/10.1016/j.enbuild.2022.111890">Daylight |
| 2157 |
+ |
Simulation Workflows Incorporating Measured Bidirectional |
| 2158 |
+ |
Scattering Distribution Functions</a>" |
| 2159 |
+ |
<em>Energy & Buildings</em>, Vol. 259, No. 11890, 2022. |
| 2160 |
+ |
<li>Wang, Taoning, Gregory Ward, Eleanor Lee, |
| 2161 |
+ |
"<a href="https://authors.elsevier.com/a/1XQ0a1M7zGwT7v">Efficient |
| 2162 |
+ |
modeling of optically-complex, non-coplanar exterior shading: |
| 2163 |
+ |
Validation of matrix algebraic methods</a>" |
| 2164 |
+ |
<em>Energy & Buildings</em>, vol. 174, pp. 464-83, Sept. 2018. |
| 2165 |
+ |
<li>Lee, Eleanor S., David Geisler-Moroder, Gregory Ward, |
| 2166 |
+ |
"<a href="https://eta.lbl.gov/sites/default/files/publications/solar_energy.pdf">Modeling |
| 2167 |
+ |
the direct sun component in buildings using matrix |
| 2168 |
+ |
algebraic approaches: Methods and |
| 2169 |
+ |
validation</a>," <em>Solar Energy</em>, |
| 2170 |
+ |
vol. 160, 15 January 2018, pp 380-395. |
| 2171 |
+ |
<li>Narain, Rahul, Rachel A. Albert, Abdullah Bulbul, |
| 2172 |
+ |
Gregory J. Ward, Marty Banks, James F. O'Brien, |
| 2173 |
+ |
"<a href="http://graphics.berkeley.edu/papers/Narain-OPI-2015-08/index.html">Optimal |
| 2174 |
+ |
Presentation of Imagery with Focus |
| 2175 |
+ |
Cues on Multi-Plane Displays</a>," |
| 2176 |
+ |
<em>SIGGRAPH 2015</em>. |
| 2177 |
+ |
<li>Ward, Greg, Murat Kurt, and Nicolas Bonneel, |
| 2178 |
+ |
"<a href="papers/WMAM14_Tensor_Tree_Representation.pdf">Reducing |
| 2179 |
+ |
Anisotropic BSDF Measurement to Common Practice</a>," |
| 2180 |
+ |
<em>Workshop on Material Appearance Modeling</em>, 2014. |
| 2181 |
+ |
<li>Banks, Martin, Abdullah Bulbul, Rachel Albert, Rahul Narain, |
| 2182 |
+ |
James F. O'Brien, Gregory Ward, |
| 2183 |
+ |
"<a href="http://graphics.berkeley.edu/papers/Banks-TPO-2014-05/index.html">The |
| 2184 |
+ |
Perception of Surface Material from Disparity and Focus Cues</a>," |
| 2185 |
+ |
<em>VSS 2014</em>. |
| 2186 |
|
<li>McNeil, A., C.J. Jonsson, D. Appelfeld, G. Ward, E.S. Lee, |
| 2187 |
|
"<a href="http://gaia.lbl.gov/btech/papers/4414.pdf"> |
| 2188 |
|
A validation of a ray-tracing tool used to generate |
