Algodoo

you don't need nearly as much laser rays for this to work, right now it lags because each laser makes 1000 rays, you have to select them all, go to the script menu, then change their maxRays to 10 for example. Also the spawn code on the fuel has something wrong, you set vel to y1000 which doesn't exist, vel is [x, y] so speed in x goes first, then speed in y. if you set it to [0,0] the ball will be spawned stationary, you don't want that. you should use entity.vel so that the ball spawns at the same velocity as the fuel ball; just replace "y1000" to "entity.vel"

Also I'm not sure but I think the lasers collide with the spawned balls, you might want to change there collision layer so that the lasers only collide with the fuel

yeah it works if you set the lasers' collision layer to B but you HAVE to add a box that limits the fuel intake or you'll die of lag

oh i didnt checked my saves for a while and see who we got here, haha. thanks for the tipps and i will see if i can fix it!

but a box that limits the fuel intake?

what do you mean by that?

have the lasers set the fuel particle's timeToLive to 0.5 so that they dont hang around forever.

the time to live is even lower than 0.5 but the simulation is just so slow

its 0.15

oh the fuel particles should get deleted at the end of the exhaust
because i dont know how to script it so that the fuel particles get deleted after 5 laser hits.