Very simple example to start with: a cube diffusing in volume.
The scene.xml file:
<?xml version="1.0"?>
<Scene NB_THREADS="6" DIRECT_PATH="0" VERBOSE="1" NB_PHOTONS="100"
STORE_TRAJECTORIES="0" STORE_ERROR_TRAJECTORIES="0"
MAX_PATH_LENGTH="-1" MAX_NB_SCATTERING="-1">
<source NAME="sourceSun0" POWER="1.0" TYPE="sun" ANGLE="0.5"
SPECTRUM="red" VOLUME="World" >
<dir Z="-1.0" Y="0.3" X="0.2"></dir>
</source>
<spectrum NAME="red" DATA=" 650 1 "> </spectrum>
<camera NAME="cam0" NBPIXELSY="100" NBPIXELSX="100" GAMMA="1"
FIELD="30.0" FILTERS="filterR" VOLUME="World" >
<lens Z="3.0" Y="-3.0" X="-3.0"></lens>
<viewPoint Z="0.55" Y="0.5" X="0.5"></viewPoint>
</camera>
<spectrum NAME="filterR" DATA=" 650 1 "> </spectrum>
<surface NAME="cube_surface" MATERIALS="dielectric1"
FILE="cube.obj">
</surface>
<dielectric NAME="dielectric1" > </dielectric>
<volume NAME="cube_volume" N="1" MATERIALS="hg2"
SURFACES="cube_surface">
</volume>
<Henyey-Greenstein NAME="hg2" LA="10000000" LSTAR="0.1"
G="0"></Henyey-Greenstein>
</Scene>
The cube.obj file:
v 0.000000 1.000000 0.000000
v 0.000000 0.000000 1.000000
v 0.000000 1.000000 1.000000
v 0.000000 0.000000 0.000000
v 1.000000 0.000000 1.000000
v 1.000000 1.000000 0.000000
v 1.000000 1.000000 1.000000
v 1.000000 0.000000 0.000000
f 1 2 3
f 4 2 1
f 5 6 7
f 5 8 6
f 8 5 4
f 4 5 2
f 7 6 1
f 7 1 3
f 1 6 4
f 4 6 8
f 7 3 2
f 7 2 5