stk-code/data/gfx/rain-ground.xml

<?xml version="1.0"?>
<!--
  Particle system to simulate it's raining heavily in the ground.
  Current tests done as kart particles, but this should be per camera
  and placed like the cylinders that have rain drop textures, maybe
  with some speed compensation, so it never wastes particles (out
  of view) when camera moves really fast. Then rate can be trimmed
  down to 150/180 or 100/120, with smaller box.
-->
<particles emitter="box" box_x="12.0" box_y="0.5" box_z="12.0">

    <spreading angle="20"       />
    
    <velocity  x="0.000"
               y="0.005"
               z="0.000"         />
    
    <material  file="water-splash.png"  />
    
    <!-- Amount of particles emitted per second -->
    <rate      min="200"
               max="240"         />
    
    <!-- Minimal and maximal lifetime of a particle, in milliseconds. -->
    <lifetime  min="1000"
               max="1000"         />
    
    <!-- Size of the particles -->
    <size      min="0.35"
               max="0.70"        />

    <color     min="255 255 255"
               max="255 255 255" />

</particles>