<?xml version="1.0"?>

<!-- Constellation engine start.


     References :
     ==========

     - http://www.flightlevel350.com/Aircraft_Lockheed_C-121_Constellation-Airline_Untitled_Aviation_Video-1835.html :

     N73544 at LSZB.

-->


<PropertyList>

    <type>normal</type>
    <name>smoke</name>
    <texture>smoke.png</texture>
    <emissive>false</emissive>
    <lighting>true</lighting>

    <offsets>
      <x-m>0</x-m>
      <y-m>0</y-m>
      <z-m>0</z-m>
    </offsets>

    <condition>
     <and>
      <property>controls/environment/smoke</property>
      <or>
       <property alias="/params/cranking"/>
       <property alias="/params/running"/>
      </or>
      <less-than>                                               <!-- only cold engine -->
       <property alias="/params/cht"/>
       <value>120</value>                                       <!-- idle at minus 35 degrees celsius -->
      </less-than>
     </and>
    </condition>

    <attach>world</attach>

    <placer>
      <type>sector</type>                                       <!-- exhaust surface -->
      <radius-min-m>0.0</radius-min-m>
      <radius-max-m>0.05</radius-max-m>
    </placer>

    <shooter>
      <theta-min-deg>45</theta-min-deg>                         <!-- cone around exhaust -->
      <theta-max-deg>85</theta-max-deg>
      <phi-min-deg>60</phi-min-deg>
      <phi-max-deg>60</phi-max-deg>
      <speed-mps>
        <value>50</value>
        <spread>5</spread>
      </speed-mps>
      <rotation-speed>
        <x-max-deg-sec>15</x-max-deg-sec>
        <x-min-deg-sec>-15</x-min-deg-sec>
        <y-max-deg-sec>15</y-max-deg-sec>
        <y-min-deg-sec>-15</y-min-deg-sec>
        <z-max-deg-sec>15</z-max-deg-sec>
        <z-min-deg-sec>-15</z-min-deg-sec>
      </rotation-speed>
    </shooter>

    <counter>
      <particles-per-sec>
        <value>75</value>
        <spread>25</spread>
      </particles-per-sec>
    </counter>

    <align>billboard</align>

    <particle>
      <start>
        <color>
          <red>
            <value>0.75</value>
          </red>
          <green>
            <value>0.75</value>
          </green>
          <blue>
            <value>0.75</value>
          </blue>
          <alpha>
            <value>0.5</value>                                  <!-- deep grey smoke -->
          </alpha>
        </color>
        <size>
          <value>0.10</value>
        </size>
      </start>
      <end>
        <color>
          <red>
            <value>1.0</value>                                  <!-- white dilution -->
          </red>
          <green>
            <value>1.0</value>
          </green>
          <blue>
            <value>1.0</value>
          </blue>
          <alpha>
            <value>0.001</value>                                <!-- barely visible -->
          </alpha>
        </color>
        <size>
          <value>20</value>                                     <!-- cloud spreading -->
        </size>
      </end>
      <life-sec>
        <value>120</value>
      </life-sec>
      <mass-kg>0.0053</mass-kg>                                 <!-- lightly lighter than air -->
      <radius-m>0.1</radius-m>
    </particle>

    <program>
      <fluid>air</fluid>
      <gravity>true</gravity>
      <wind>true</wind>
    </program>

</PropertyList>
