<!-- El Sol está 30º sobre el horizonte y la cámara está 1m por encima del p.n. -->

<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 fisheye camera with 180 degrees aperture -->
  <sensor type="fisheye">
    <transform name="to_world">
      <!-- Translate the camera 1 meter above the ground at the north pole -->
      <translate x="0" y="0" z="6356.767"/>
    </transform>
    <float name="aperture" value="180"/>

    <!-- 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="160"/>
      <integer name="height" value="160"/>
    </film>
  </sensor>
  
  <!-- Distance unit: km -->
  
  <!-- Sun -->
  <shape type="sphere">
    <float name="radius" value="696340"/>
    <point name="center" x="0" y="129555556.378" z="74798935.35"/> <!-- Distance = 149597870700 meters -->
    
    <emitter type="area">
      <spectrum name="radiance" value="770000"/> <!-- 770000 W per square unit per steradian -->
    </emitter>
  </shape>
  
  <medium type="atmosphere" id="atmosphere">
    <!-- Parametres -->
    <float name="earth_radius" value="6356.766"/>
    <point name="earth_center" x="0" y="0" z="0"/>
    <string name="aerosol_model" value="PolarArticAerosol"/>
    <float name="turbidity" value="0.01"/>
  </medium>

  <!-- Earth -->
  <shape type="sphere">
    <float name="radius" value="6356.766"/>

    <bsdf type="diffuse">
      <rgb name="reflectance" value="0, 0, 0"/>
    </bsdf>
  </shape>
  
  <!-- Earth atmosphere -->
  <shape type="sphere">
    <float name="radius" value="6443.77"/>
    <point name="center" x="0" y="0" z="0"/>
    
    <bsdf type="null"/>
    
    <ref id="atmosphere" name="interior"/>
  </shape>
  
  <shape type="sphere">
    <float name="radius" value="0.001"/>
    <point name="center" x="0" y="0" z="6356.767"/>
    <boolean name="flip_normals" value="true"/>

    <bsdf type="null"/>
      
    <ref id="atmosphere" name="interior"/>
  </shape>
</scene>