AI + interpolate = very good shot

Hi,

(skip to bold if you want :P )

I've been working on aiPlayer.cs for about a week now (pretty new at torque), in an attempt to both learn the language and make a sem-decent bot. Up til now I've been trying to get it to follow the player using waypoints (A* precompiled navnets from a very nice resource :) ), as well as dodge, choose targets intelligently and have "characteristics" which can be different for each bot I spawn.

Tonight I tackled the actual aiming of the bot, as my current .setAimObject(%target, "0 0 2.8") was not up to scratch. I had heard of interpolation, and decided to have a go at making my own interpolate function for my bots. Basicly, my bot takes the position of the player, the speed of the bots current projectile, and the velocity of the player, and attempts to "guess" where the player will be in the time taken for the projectile to reach him.

The real reason I posted this thread was for a little advice, and to show off my nice interpolate function :)

(skip to bold again if you just want the code, and to help me with my problem!)

So, the bot works out where the player will be in x seconds (x being the time taken for proj to get to his position), however, where the player will be in x seconds might mean it will take y seconds for the projectile to get there, not x - this conundrum I think I have solved :)

I played around with an offset, adjusting %projectileTimeToGetThere by 0.1 though to 1. I collected echo()'ed out my distance from the bot whilst circling it - and to cut a long story short got some data, of which I had a correlation of 0.97ish - I was very happy :)

Anyway, I worked out the linear regression line of my data, and now my bot hits me ALOT of the time - seriously 9 times out of 10 at least! He really is an excellent shot now!

On with the code! Although I recomend you read my badly written post anyway!

No idea how you want to implement this, and I don't want to restrict you, so I'll just post the main bit of my interpolate function (doesn't check to see if we have a target, if we are dead etc etc)

function AIPlayer::InterpolateAim(%this, %cancel)
{
	if (%cancel == true)
	{
		cancel(%this.interpolateSchedule);
		return 0;
	}
	if (!isObject(%this.curTarget["Player"]))
	{
		//target has died
		cancel(%this.interpolateSchedule);
		return 0;
	}
	if (%this.getState() $= "dead")		// check we are not dead
	{
		cancel(%this.interpolateSchedule);
		return 0;
	}
	//%targetPosition, %targetDistance, %targetVelocity, %projSpeed
	[b]%projectileSpeed = 20; //need help here!!! [/b]
	%targetVelocity = %this.curTarget["Player"].getVelocity();
	%targetPosition = %this.curTarget["Player"].getPosition();
	%targetDistance = vectorDist(%this.getPosition(), %targetPosition);
	%projTTL = %targetDistance / %projectileSpeed;
	[b]%offset = 0.35 + 0.03742 * (%targetDistance - 10.8333); //!!!!!!! the magic bit! [/b]
	%projTTL = %projTTL - %offset;
	%interpolatedTargetPosition = 
		getWord(%targetPosition,0) + (%projTTL * getWord(%targetVelocity,0)) SPC
		getWord(%targetPosition,1) + (%projTTL * getWord(%targetVelocity,1)) SPC
		getWord(%targetPosition,2) + (%projTTL * getWord(%targetVelocity,2)) + 2.8;
		//2.8 is required to make it aim at my head!
	%this.setAimLocation(%interpolatedTargetPosition);
	%this.interpolateSchedule = %this.schedule(100, InterpolateAim);

}

the bit I have bolded is where I need help myself - I have no idea how to get the projectile speed at runtime, so I just looked it up in crossbow.cs (still using default crossbow) and put in muzzleVelocity.

Anyway, to summerise a (stupidly) long post, have a go with this interpolate function, %this.curTarget["Player"] is just the handle of my current target as a player object - you could of course add a parameter which is the %player. I think everything else is self-explanatory - and I'd be very grateful if someone could help me with my problem (see above)!!!