<scene version="2.2.1">
  <integrator type="volpath">
    <!-- Instantiate a path tracer with a max. path length of 128 -->
    <integer name="max_depth" value="128"/>
  </integrator>

  <!-- Instantiate a perspective camera with 45 degrees field of view -->
  <sensor type="perspective">
    <!-- Rotate the camera around the Y axis by 180 degrees -->
    <transform name="to_world">
      <rotate x="1" angle="90"/>
      <rotate z="1" angle="45"/>
      <translate x="-1767.5" y="1767.5" z="500"/>
    </transform>
    <float name="fov" value="15"/>

    <!-- Render with 121 samples per pixel using a stratified sampling strategy -->
    <sampler type="stratified">
      <integer name="sample_count" value="121"/>
    </sampler>

    <!-- Generate an EXR image -->
    <film type="hdrfilm">
      <integer name="width" value="640"/>
      <integer name="height" value="360"/>
    </film>
  </sensor>
  
  <!-- Distance unit: 10^4 meters -->
  
  <!-- Sun -->
  <shape type="sphere">
    <float name="radius" value="69634.0"/>
    <point name="center" x="0" y="14843292.6919" z="1863301.16798"/> <!-- Distance = 149597.870700 * 10^6 meters -->
    
    <emitter type="area">
      <spectrum name="radiance" value="770000"/> <!-- 770000 W per square unit per steradian -->
    </emitter>
  </shape>

  <!-- Earth -->
  <shape type="sphere">
    <float name="radius" value="635.6767"/>

    <bsdf type="diffuse">
      <texture type="bitmap" name="reflectance">
        <string name="filename" value="earth2.jpg"/>
      </texture>
    </bsdf>
  </shape>
  
  <!-- Earth atmosphere -->
  <shape type="sphere">
    <float name="radius" value="644.377"/>
    <point name="center" x="0" y="0" z="0"/>
    
    <bsdf type="null"/>
    
    <medium type="atmosphere" name="interior">
      <!-- Parametres -->
      <float name="earth_radius" value="635.6767"/>
      <point name="earth_center" x="0" y="0" z="0"/>
    </medium>
  </shape>
</scene>