Hi. Thanks all for you replies i have one more question before trying to write something on top of that, your algorithme Joe, does it works if the way has some bifurcations, i mean, a fully linear way but that contain bifurcations.
Thanks. 2011/7/20 Joe Ranalli <jrana...@gmail.com> > It depends what you're trying to do. > > If you draw the straight line between the tower and the enemy and use that > vector to translate a bullet each tick, the bullets might miss the enemy. > Think about it this way, the bullet moves 2 steps toward the enemy, then the > enemy moves 1 step, then the bullet moves 2, etc. Because the enemy moves > the bullet will have to change its direction through the flight. So you > could calculate the direction vector between the bullet and the enemy every > tick and have the bullet move that direction. That would make the bullets > kind of arc to the target. > > If you want to have the bullet go straight to the right spot, you need to: > 1) calculate how long the bullet will take to get to the enemy > 2) calculate where the enemy will be at that time (newposition) > 3) calculate how long it will take the bullet to get to newposition > 4) recalculate newposition based on the new time > > Technically you could iterate that repeatedly until newposition converges. > Practically, iterating once probably gets you close enough unless the > movement is extremely complicated. > > > On Wed, Jul 20, 2011 at 9:14 AM, Nathan BIAGINI <nathan.o...@gmail.com>wrote: > >> Hi everyone, >> >> i would like to know what are the common way to handle "trajectory" in a >> 2d game. In fact, i think of writing a tower defense game and i wonder how >> to handle the trajectory of the missile launch by the towers. I though of >> getting the pos of the tower and the target and create a vector between this >> two entitites to make a sprite translation of this vector but there is maybe >> some tricky stuff to do it. >> >> Thanks in advance and happy game making all :-) >> > >
