Thank You for the 16-01-2012: Update! Pathfinding has key importance in games with enemies.
I was thinking about what my colleagues did for Nintendo NDS. Pathfinding wasn't coded into the car-racing game for (possibly) performance or limited time reasons. Spline paths were laid down along the race-tracks and enemy cars followed those invisible splines. It turned out not so bad.
So here is the idea: how reasonable is to lay down "splines" paths on the level and detect if the target is crossing one spline. Like when a soldier touches a wire-trap in a jungle war-game. Enemies would then change to that spline-track and travel down to the point where the target last touched the "wire".
I'm pondering how realistic would it be. Maybe the enemy heard something and follows the noise, goes to the last known target(player) position.
Apparently, not completely done ^^
mercy: The actual PF kinda acts like the spline method you describe.
Instead of a line though, it's cells, covering more ground at a time.
The downside is that the testing zone is the whole layout at once, cell/cell.
I may have some plans "someday" to push the developpment on the PF to allow the user to set the scan zone to optimize performances.
But it is not in a close future, I have other projects that I need to take care of first, and those projects don't require a PF as of now.
For your "spline"/"line of sight" method I'd go with events, positioning a "marker" on a regular basis (maybe not every tick, maybe something like every 0.1 seconds), and checking for collisions on the positioning (or the following tick).
Gotta use some finish state machinery here, but it should work pretty well and not require a lot of events (especialy if you use families) or performances.
I think it's reasonably doable.
Check the how do I FAQ, there are some LOS examples listed in it that might give you some leads.
My answer is maybe a bit unclear and certainly not complete.
If you want to learn more/have more feedback on this idea just post a new topic in the how do I section, you should get some more complete answers in the couple of day/weeks following the thread.
Done for now for good <img src="smileys/smiley1.gif" border="0" align="middle" />