Fade

The Fade alteration will cause the sprite to incrementally change its transparency.
This effects the alpha value of the sprite. Therefore, to fade, you must specify a negative value for the rate and to unfade, use a positive value.

View example in tutorial


create routine as Start launch horse end
create sprite from horse12.png as horse
  where x=100 and y=100
  having alt=(sub create fade as f where rate=-0.5 and until=0.1 end)
end

Parameters

rate={number}: a fade rate per second. Use a negative value to fade (increase transparency) and a positive value to make the sprite more opaque.
until={number}: the value at which the fade should end. Also, the final alpha value for the sprite. Must be a value between 0.0 and 1.0. Be sure this number makes sense with respect to the initial alpha of the sprite and the rate being negative or positive.
completion={routine}: specify a routine to run when the fade is complete.