a small transparency tip
(hat-tip to @hamoid)
there’s the quite well-known technique of painting a more or less transparent rectangle each frame (instead of a full background) in order to get objects to create more or less long trails.
but if you set the alpha below a certain value, like 25, then you start getting smudgy ‘leftovers’ like this:
and if you decrease the alpha to 1 (to get really long streaks) then the ‘leftovers’ will be really visible and ugly ( = grey) :
but if instead of simply writing:
fill(0,1);
rect(0,0,width, height);
you write:
blendMode(SUBTRACT);
fill(1);
rect(0,0,width, height);
blendMode(BLEND);
then you get this:
so that’s the longest trail that you can create with the alpha technique.
if you’d like to shorten the trail then simply increase the color value to something like 2 or 5, like fill(2) or fill(5).
(code)
theartofanimation