Algodoo

That's very nice. I made some script that you can use if you want:

for(10, (i)=>{
scene.AddCircle({
pos := e.pos;
radius := 0.1;
color := [1, 1, 0, 0];
edgeblur := 100;
timeToLive := 1;
poststep := (e)=>{
vel = [rand.normal * 2, rand.normal * 2]
};
collideset := 0
});
Scene.addPen({
pos := e.pos;
timeToLive := 1;
color := {
[timeToLive * 2 + 0.7, timeToLive * 2 + 0.7, timeToLive + 0.5, 1]
};
fadeTime := 1.5;
size := 0.5
})
});
for(10, (i)=>{
scene.AddCircle({
pos := e.pos;
radius := 0.1;
color := [1, 1, 0, 0];
edgeblur := 100;
timeToLive := 1;
poststep := (e)=>{
vel = [rand.normal * 10, rand.normal * 10]
};
collideset := 0
});
Scene.addPen({
pos := e.pos;
timeToLive := 1;
color := {
[timeToLive * 2 + 0.7, timeToLive * 2 + 0.7, timeToLive + 0.5, 1]
};
fadeTime := 1.5;
size := 0.1
})
});