mrumtl.5 (3324B)
1 .\" Copyright (C) 2020, 2023 |Méso|Star> (contact@meso-star.com) 2 .\" 3 .\" This program is free software: you can redistribute it and/or modify 4 .\" it under the terms of the GNU General Public License as published by 5 .\" the Free Software Foundation, either version 3 of the License, or 6 .\" (at your option) any later version. 7 .\" 8 .\" This program is distributed in the hope that it will be useful, 9 .\" but WITHOUT ANY WARRANTY; without even the implied warranty of 10 .\" MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 11 .\" GNU General Public License for more details. 12 .\" 13 .\" You should have received a copy of the GNU General Public License 14 .\" along with this program. If not, see <http://www.gnu.org/licenses/>. 15 .Dd October 4, 2023 16 .Dt MRUMTL 5 17 .Os 18 .Sh NAME 19 .Nm mrumtl 20 .Nd ModRadUrb MaTeriaL file format 21 .Sh DESCRIPTION 22 .Nm 23 is a text file format that describes a Bidirectional Reflectance 24 Distribution Function 25 .Pq BRDF 26 whose type and parameters can vary spectrally. 27 Its data are described for a set of wavelengths or spectral bands that must be 28 listed in ascending order. 29 .Pp 30 Characters behind the hash mark 31 .Pq Li # 32 are considered comments and are therefore ignored, as well as empty lines, 33 i.e. lines without any characters or composed only of spaces and tabs. 34 .Pp 35 The file format is as follows: 36 .Bl -column (per-band-BRDF) (::=) () 37 .It Ao Va mrumtl Ac Ta ::= Ta Ao Va per-wlen-BRDF Ac | Ao Va per-band-BRDF Ac 38 .It \ Ta Ta 39 .It Ao Va per-wlen-BRDF Ac Ta ::= Ta Li wavelength Ao Va #wavelengths Ac 40 .It Ta Ta Ao Va wlen-BRDF Ac 41 .It Ta Ta Va ... 42 .It Ao Va wlen-BRDF Ac Ta ::= Ta Ao Va wavelength Ac Ao Va BRDF Ac 43 .It Ao Va #wavelength Ac Ta ::= Ta Va integer 44 .It Ao Va wavelength Ac Ta ::= Ta Va real 45 # In nanometer 46 .It \ Ta Ta 47 .It Ao Va per-band-BRDF Ac Ta ::= Ta Li bands Ao Va #bands Ac 48 .It Ta Ta Ao Va band-BRDF Ac 49 .It Ta Ta Va ... 50 .It Ao Va #bands Ac Ta ::= Ta Va integer 51 .It Ao Va band-BRDF Ac Ta ::= Ta 52 .Aq Va wavelength-min 53 .Aq Va wavelength-max 54 .Aq Va BRDF 55 .It Ao Va wavelength-min Ac Ta ::= Ta Va real 56 # Inclusive bound in nm 57 .It Ao Va wavelength-max Ac Ta ::= Ta Va real 58 # Inclusive bound in nm 59 .It \ Ta Ta 60 .It Ao Va BRDF Ac Ta ::= Ta 61 .Aq Va BRDF-lambertian 62 | 63 .Aq Va BRDF-specular 64 .It Ao Va BRDF-lambertian Ac Ta ::= Ta Li lambertian Ao Va reflectivity Ac 65 .It Ao Va BRDF-specular Ac Ta ::= Ta Li specular Ao Va reflectivity Ac 66 .It Ao Va reflectivity Ac Ta ::= Ta Va real 67 # In [0, 1] 68 .El 69 .Sh EXAMPLES 70 Describe a material with only two bands: one for the visible part of the 71 spectrum and one for the long waves. 72 In both cases use a diffuse reflectivity: 73 .Bd -literal -offset indent 74 bands 2 75 380 780 lambertian 0.9 # Visible part 76 1000 100000 lambertian 0.1 # Infrared 77 .Ed 78 .Pp 79 Setup a material for a list of 17 wavelengths. 80 This material is diffuse in short waves and specular in long waves: 81 .Bd -literal -offset indent 82 wavelengths 17 83 84 # Short waves 85 430 lambertian 5.2e-2 86 450 lambertian 6.2e-2 87 500 lambertian 6.5e-002 88 600 lambertian 0.165 89 750 lambertian 0.175 90 91 # Long waves 92 1100 specular 0.1 93 1300 specular 0.17 94 1400 specular 0.1 95 2000 specular 0.1 96 2100 specular 0.4 97 2300 specular 0.18 98 2500 specular 0.9 99 2600 specular 0.95 100 2900 specular 0.4 101 3000 specular 0.3 102 4000 specular 0.0 103 100000 specular 0.0 104 .Ed