Missile Accuracy: A Mystery

[Kobal2fr]

@Foz : I feel pompous for pointing the obvious but.. Foz, have you considered that maybe the EDU range variables are affected by the same modifiers than the more math/physics factors listed in descr_proj ? Or that the code using said variables takes physics into account, kind of like it takes unit facing into account for the shield variable ?

[Foz]

This thread contains images of camel gunners firing from a mountain top at English knights on a beach below. https://forums.totalwar.org/vb/showthread.php?t=85272. The question is whether the range is being limited by 'range of missile' or by the routine which handles missile flight trajectory. If it were the former then I would expect the missiles to simply dissappear in flight, regardless of whether they hit anything (like the ground) but in this instance they were definately carrying the full distance until the hit terra firma. The other interesting thing to note is that the horizonal distance between the camel gunners and the English, as depicted on the mini-map, doesn't look that great, so possibly the 'range of missile' is merely working on horzontal distance to target within which a missile unit will be allowed to target and shoot, and ignoring the distance the projectile will actually travel once it is fired.

Jesus that's ridiculous! That certainly establishes that the EDU range is not a simple horizontal limitation, nor a 3-D distance limitation.

One question I have is did the game allow you to target those men, or were your gunners on auto-fire mode? There may be disparity between the two, so any info you can give for either would be useful.

Is there any way of determining how this 'range of missile' is used within the code, if its used at all?

You'd probably have to hex edit the game executable to find it. That's not really my thing, so I'm gonna say it's basically a "no."

Or indeed what the range is in terms of battlefield distance?

It shouldn't be too hard to establish a coordinate basis at least in the horizontal directions. You can probably get a good estimate by taking an archer unit, setting its EDU range arbitrarily large, and figuring out how far it shoots just based on velocity in descr_projectiles and 45 degree shooting. Then you make it shoot something at max range, and note that the shot must have traveled ~max range. That should give a reasonable idea of how big a game meter is (the specs are all supposed to be in meters IIRC).

An alternative is to eyeball it based on the apparent height of a unit. The scale of men to buildings and such seems reasonable, so it seems like the apparent height of a man could be ~equivalent to real life.

and do all missile units have it?

Yup. It's not always the same, though, and it's possible that even units firing the same projectile type may have different range of missile amounts. I haven't looked at it hard enough to know if there are any such cases, though. Typical values for archers and crossbows are usually either 120m or 160m IIRC.

@Foz : I feel pompous for pointing the obvious but.. Foz, have you considered that maybe the EDU range variables are affected by the same modifiers than the more math/physics factors listed in descr_proj ? Or that the code using said variables takes physics into account, kind of like it takes unit facing into account for the shield variable ?

Oh that's not pompous, not even remotely. I did think of that, yes. As I said before, though, I'm not arguing a viewpoint, I'm really trying to pry sufficient evidence out of people to support their own viewpoint/theory.

These past few posts have brought us a long way as a result. Only two possibilities I can think of would be left:

1. EDU range is ignored entirely
2. EDU range is a bound for a flat shot

#1 I don't believe is possible, as you can increase the velocity of projectiles by insane amounts and see no reflected increase in range on flat ground. That leaves only #2, which as far as I can see is the only explanation. In theory the listed EDU range would be somehow modified to allow very long shots from above targets and shorter ones when below, but I can't figure out a reasonable way that this might be done that makes sense for all 3 possible scenarios.

[Didz]

One question I have is did the game allow you to target those men, or were your gunners on auto-fire mode? There may be disparity between the two, so any info you can give for either would be useful.

As I recall they just began firing on auto-fire. Personally I have never come across a situation where auto-fire kicked in and I was unable to intervene as choose a target manually.

In fact, a common tactic that I use in seige sallies is to advance my artillery out of the gate until auto-fire kicks in confirming that they are in range and then interfere to switch the target to the unit I want them to concentrate upon.

Changing the subject slightly....one thing that has always impressed me about the way CA have implemented their missile fire is the way the trajectory system decides whether a missile has hit a target or not. In seiges for example when attacking the inner curtain wall its perfect possible to have units hug the walls of the houses along the streets as cover to minimise casualties. Its a little thing but its amazing how many other games don't handle that sort of thing at all, and most of course use the magic missile system that allows fire through your own troops too.