Revision history [back]

It seems it was due to the fact my cameras used noise. I used the model described in the tutorial,

<camera>
  <horizontal_fov>1.047</horizontal_fov>
  <image>
    <width>1024</width>
    <height>1024</height>
  </image>
  <clip>
    <near>0.1</near>
    <far>100</far>
  </clip>
  <noise>
    <type>gaussian</type>
    <mean>0.0</mean>
    <stddev>0.007</stddev>
  </noise>
</camera>

Without this noise, I don't have the background color error anymore. I don't really know if it was specific to my platform.