Nuclear thread - can we go ballistic?

Hi all,
I was wondering about two moments regarding the use of strategic missiles:

1. The ballistic parabola - currently there is none. Even stranger, actually the tactical missiles do employ a viable parabola, which should not be forgotten, as the TM can be destroyed by the terrain.
   Now, I’m not saying the SM should have a parabola that can be affected by terrain, but the whole point of delivering a nuclear warhead is to do it as fast as possible, and not letting a warhead do a 90 degree turn above the enemy base, letting them make a final second SMD projectile during the last seconds of SM flight, which has happened during some games you’ve played, I suppose.
2. Explosion height - I think it is very unrealistic for a nuclear warhead to wait until it smashes into the ground to explode.
   I made some research and it seems that for a 30 units radius devastation, a nuclear warhead should explode at least 3-6 units above the ground zero.
   While also being nit picking, these two issues have a slight balance wise side attached to SM, as I think currently the nukes are underused.
   Would like to hear thoughts whether this could be implemented.

It can both be implemented, but a parabola trajectory is not recommended. it means that intermediate SMDs can not intercept the missile.

I've been tooling around with the same idea. I agree the current trajectory is a little strange and a ballistic trajectory would spice things up.

I wasn't aware SMDs could intercept missiles mid-flight as is, but was going to recommend it. SMDs can intercept missiles of an arbitrary height if you add MaxHeightDiff to their weapon blueprints ("changes the weapon range from spherical to cylindrical, where the cylinder has a height of this twice this value"). That may or not work as stated given that no units currently use it.

This could be tweaked so SMDs could intercept missiles only in the "boost" and re-entry phase (or even allow smaller, less capable SMDs to be added...!), but not at the highest point of their trajectory, which has a certain je ne sais quoi.

There's been a long time conversation of reworking tactical missile trajectories as well, for performance reasons. If someone with some background knowledge on missile guidance and trajectories (ahem) was given a little flexibility to shift things around* we could knock out both at the same time.

*Recognizing there's some balance implications with tactical missile trajectories in regards to TML, hide spots in Astro Crater, etc.

That discussion got kickstarted again with this:

• https://github.com/FAForever/fa/pull/5369

If someone with some background knowledge on missile guidance and trajectories (ahem) was given a little flexibility to shift things around* we could knock out both at the same time.

I don't think we need someone like that. It is just a matter of setting the correct turn rate at the right time and call it a day. That's how it has worked for 13 years now

Yes, I should correct and say that tactical missiles are simple. Putting a good looking trajectory on strategic missiles is a little more involved, though I brought up Astro Crater because even slight changes to TM trajectory might change the safe areas there (not that I'm chomping at the bit to work around Crater--can't whoever made the map to begin with make another one in five minutes?).

@jip said in Nuclear thread - can we go ballistic?:

It can both be implemented, but a parabola trajectory is not recommended. it means that intermediate SMDs can not intercept the missile.

What would an intermediate SMD be?

SMD that intercepts an SML without actually having the intended target within its intended range.

A ballistic parabola only makes sense for unpropelled missiles, but the nuke obviously burns the whole time. It's more like a guided cruise missile.

The 90 degree turn is to avoid terrain collisions, but I guess we could increase the turn radius, so it looks a bit smoother

Re point 2, for me this is one of those areas where what's fun/intuitive in a game trumps what might be the technically more realistic approach. If I launch a big missile at a target, I expect the missile to explode on impact, not to explode in the air above the target.

@blackyps

I suspect the current in-game behavior of strat missiles is a result of what was easiest/fastest to implement at the time, while their form and function is very clearly modeled on ICBMs.

I'm indifferent on ground vs. air burst (and therefore inclined to the status quo) as the real-life lore behind it has no relevance to the sim, unlike trajectory.

how is their function modelled on ICBMs when their range is 80km and they burn the whole flight time?

Range is actually 390.625 km (read as: infinite, within the scope of the game).

"Burn" gets realll fuzzy real quick, because only acceleration is modeled. But given that the missile goes into space (as in, higher than a satellite) and maintains a constant speed, we can surmise that it's not under thrust despite what the flames coming out the back would suggest.

But man I really don't think "nuclear tipped strategic missile vertically launched from a hardened silo is modeled on an ICBM" is the sticking point in this conversation. Do we need to go house to house on this?

The complaint was that there was no balistic parabola, which only makes sense if there is no trust.

we can surmise that it's not under thrust despite what the flames coming out the back would suggest.

Uhhh, yeah I think we can all agree that the notion of things being in space or not falls apart quite a bit in this game. The satellite for example is obviously lower than it should be, because keeping it to scale would be way too clunky to use.
I think it extrapolates to the nuke. The devs designed what they thought looked cool, and I am somewhat confident that the flight path was a pragmatic decision to allow intercepting of the nuke during the complete flight while also being sure to avoid terrain

My original statement was that a ballistic trajectory would be cool. As previously mentioned it's trivial to modify SMD to intercept missiles at an arbitrary height. Let's agree to disagree on the rest of it.

Agreed

Hot fact: SMD will already intercept a nuke of any height. There's something weird with the targeting code (relies on OnGotTarget, somehow), but it'll do it. Only side effect of shooting at a nuke at a ridiculous altitude is that you waste any extra missiles in the SMD silo because the first one takes so long to connect and the SMD keeps shooting until it does.

I am as knowledgeable and interested in missiles as anybody, but I think the FAF nuke is fine as it is. The main problem with parabolic trajectories is that shots are hard to see when they fly that high, as in the case of T3 artillery and Mavors. The current nuke behavior is theatric rather than true to life. The same is true for the slow decent of the missile over its target. In real life, nuclear warheads approach targets at speeds exceeding mach 5. In Faf terms, that's almost a beam weapon.

Then there's the balance problem: Nukes are balanced against bases, because nukes are slow, but bases can't move. Obviously, a realistic fast nuke would change quite a lot about balance and would greatly favor ACU snipes.

Tldr: it's not realistic as it is, but it's fine

@blackyps said in Nuclear thread - can we go ballistic?:

A ballistic parabola only makes sense for unpropelled missiles, but the nuke obviously burns the whole time. It's more like a guided cruise missile.

The 90 degree turn is to avoid terrain collisions, but I guess we could increase the turn radius, so it looks a bit smoother

I think a turn radius increase is a viable option, if admins are willing to change anything at all.

@slicknixon said in Nuclear thread - can we go ballistic?:

@blackyps

I'm indifferent on ground vs. air burst (and therefore inclined to the status quo) as the real-life lore behind it has no relevance to the sim, unlike trajectory.

I would disagree, as the nuke is a superweapon, okay not generally an ICBM, but rather like a real world very powerful tactical nuke, in our sim and not a single projectile aimed at a certain unit or a point of area, and in terms of a superweapon it should act like one e.g. explosion in air for maximum devastation, and a parabolic, or at least have a greater radius, delivery in order to minimize chances of taking it down.

Nukes don't need a buff by blowing up 5 seconds earlier.