Kill outcomes: falling hull, breakup or air detonation by weapon and target, recorded for replays (#97)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

airdef-mod/src/film.rs

@@ -308,10 +308,15 @@ fn plan_event(rec: &Recording, i: usize, floor: f64) -> Vec<Shot> {
         Some(Shot::new(a, b, &[(a, 1.0), (b, 1.4)], variants, head, "", i))
     };
     match e.kind {
-        EventKind::Kill { drone, kind, sam, sam_kind, sam_index, missile } => {
+        EventKind::Kill { drone, kind, sam, sam_kind, sam_index, missile, outcome } => {
             let sp = rec.sam(sam).map_or(pos - DVec3::new(150.0, 0.0, 0.0), |s| s.1);
             let name = format!("{} №{}", sam_kind.name(), sam_index + 1);
-            let sub = format!("Перехват «{}»", kind.spec().name);
+            let how = match outcome {
+                crate::sim::outcome::Outcome::DisabledFalling => "",
+                crate::sim::outcome::Outcome::Breakup => ": разрушение в воздухе",
+                crate::sim::outcome::Outcome::AirDetonation => ": детонация в воздухе",
+            };
+            let sub = format!("Перехват «{}»{how}", kind.spec().name);
             let mt = missile.and_then(|m| rec.track(m).map(|t| (m, t.first as f64)));
             match mt {
                 Some((m, tl)) => {
@@ -638,7 +643,7 @@ mod tests {
         rec.events.push(Event {
             at: kill,
             pos,
-            kind: EventKind::Kill { drone: 1, kind: DroneKind::Geran3, sam: 5, sam_kind: SamKind::S400, sam_index: 0, missile: missile.then_some(2) },
+            kind: EventKind::Kill { drone: 1, kind: DroneKind::Geran3, sam: 5, sam_kind: SamKind::S400, sam_index: 0, missile: missile.then_some(2), outcome: Default::default() },
         });
         rec
     }

airdef-mod/src/replay.rs

@@ -125,13 +125,23 @@ fn clock(ticks: f64) -> String {
     format!("{:02}:{:04.1}", (s / 60.0) as u32, s % 60.0)
 }
 
+/// How a kill ended, when it was not the plain fall.
+fn outcome_note(outcome: crate::sim::outcome::Outcome) -> &'static str {
+    use crate::sim::outcome::Outcome;
+    match outcome {
+        Outcome::DisabledFalling => "",
+        Outcome::Breakup => " (разрушение)",
+        Outcome::AirDetonation => " (детонация в воздухе)",
+    }
+}
+
 /// What an event was, in a line.
 pub fn title(rec: &Recording, i: usize) -> String {
     let e = &rec.events[i];
     match e.kind {
-        EventKind::Kill { kind, sam_kind, sam_index, missile, .. } => {
+        EventKind::Kill { kind, sam_kind, sam_index, missile, outcome, .. } => {
             let how = if missile.is_some() { "ракетой" } else { "огнём пушек" };
-            format!("{} №{} сбивает «{}» {how}", sam_kind.name(), sam_index + 1, kind.spec().name)
+            format!("{} №{} сбивает «{}» {how}{}", sam_kind.name(), sam_index + 1, kind.spec().name, outcome_note(outcome))
         }
         EventKind::Hit { kind, object: Some(o), .. } => format!("«{}» поражает объект №{}", kind.spec().name, o + 1),
         EventKind::Hit { kind, sam: Some((sk, si)), .. } => format!("«{}» бьёт по {} №{}", kind.spec().name, sk.name(), si + 1),
@@ -146,8 +156,8 @@ pub fn title(rec: &Recording, i: usize) -> String {
 pub fn row(rec: &Recording, i: usize) -> String {
     let e = &rec.events[i];
     let what = match e.kind {
-        EventKind::Kill { kind, sam_kind, sam_index, missile, .. } => {
-            format!("{}-{} > {}{}", sam_kind.name(), sam_index + 1, kind.spec().name, if missile.is_none() { " (пушки)" } else { "" })
+        EventKind::Kill { kind, sam_kind, sam_index, missile, outcome, .. } => {
+            format!("{}-{} > {}{}{}", sam_kind.name(), sam_index + 1, kind.spec().name, if missile.is_none() { " (пушки)" } else { "" }, outcome_note(outcome))
         }
         EventKind::Hit { kind, object: Some(o), .. } => format!("{} > объект {}", kind.spec().name, o + 1),
         EventKind::Hit { kind, sam: Some((sk, si)), .. } => format!("{} > {}-{}", kind.spec().name, sk.name(), si + 1),
@@ -163,8 +173,9 @@ pub fn row(rec: &Recording, i: usize) -> String {
 pub fn interest(rec: &Recording, i: usize) -> f64 {
     let e = &rec.events[i];
     match e.kind {
-        EventKind::Kill { kind, missile, .. } => {
+        EventKind::Kill { kind, missile, outcome, .. } => {
             let spec = kind.spec();
+            let bonus = if outcome == crate::sim::outcome::Outcome::AirDetonation { 2.0 } else { 0.0 };
             let class = match spec.class {
                 Class::Ballistic => 10.0,
                 Class::Supersonic => 7.0,
@@ -179,7 +190,7 @@ pub fn interest(rec: &Recording, i: usize) -> f64 {
             };
             // A kill close to what it was going for.
             let close = rec.objects.iter().chain(rec.sams.iter().map(|s| &s.2)).any(|o| o.distance(e.pos) < 40.0);
-            class + rare + if spec.decoy { -3.0 } else { 0.0 } + if missile.is_none() { 1.0 } else { 0.0 } + if close { 3.0 } else { 0.0 }
+            bonus + class + rare + if spec.decoy { -3.0 } else { 0.0 } + if missile.is_none() { 1.0 } else { 0.0 } + if close { 3.0 } else { 0.0 }
         }
         EventKind::Hit { power, object, sam, .. } => {
             power as f64 * 1.5 + if object.is_some() { 6.0 } else if sam.is_some() { 5.0 } else { 0.0 }
@@ -439,13 +450,16 @@ impl Player {
         let heard = |p: DVec3| listener + (p - self.eye);
         for e in rec.events.iter().filter(|e| (self.heard..self.t).contains(&(e.at as f64))) {
             let event = match e.kind {
-                EventKind::Kill { .. } => "airdef:blast.air",
+                EventKind::Kill { kind, outcome, .. } => crate::sim::outcome::look(kind, outcome).3,
                 EventKind::Hit { power, .. } | EventKind::Crash { power, .. } => ["airdef:blast.air", "airdef:blast.medium", "airdef:blast.big", "airdef:blast.heavy", "airdef:blast.huge"][(power as usize).min(4)],
                 EventKind::SamLost { .. } => "airdef:blast.big",
                 EventKind::Split { .. } => "airdef:boom.sonic",
             };
-            let gain = if let EventKind::Kill { kind, .. } = e.kind { crate::sim::record::kill_look(kind).2 } else { 1.0 };
+            let gain = if let EventKind::Kill { kind, outcome, .. } = e.kind { crate::sim::outcome::look(kind, outcome).2 } else { 1.0 };
             out.sound(event, heard(e.pos), gain, 1.0);
+            if let EventKind::Kill { outcome: crate::sim::outcome::Outcome::AirDetonation, .. } = e.kind {
+                out.sound("airdef:boom.sonic", heard(e.pos), 0.8, 1.2);
+            }
         }
         for tr in rec.tracks.iter().filter(|tr| (self.heard..self.t).contains(&(tr.first as f64))) {
             if let What::Missile(kind, _) = tr.what

airdef-mod/src/sim/mod.rs

@@ -20,6 +20,7 @@ mod ew;
 pub mod lights;
 mod logistics;
 mod orders;
+pub mod outcome;
 mod units;
 mod why;
 pub mod world;
@@ -31,6 +32,7 @@ pub use ew::EW_RADIUS;
 pub use damage::{Comps, Part, PartState};
 pub use sight::{Ident, Track};
 use damage::dice;
+use outcome::{Impact, Outcome};
 pub use units::{Family, SamKind};
 use units::Muzzle;
 pub use raid::{Approach, Aim, RaidOrder};
@@ -1375,6 +1377,8 @@ enum Fx {
     Fireball { pos: DVec3, size: f64, age: u32, life: u32, spin: DQuat },
     /// A falling piece of a drone.
     Debris { pos: DVec3, vel: DVec3, rot: DQuat, spin: DQuat, age: u32 },
+    /// A piece thrown off by a breakup or an air detonation: its own drag and life.
+    Piece { pos: DVec3, vel: DVec3, rot: DQuat, piece: outcome::Piece, age: u32 },
     /// A glowing red tracer round.
     Tracer { pos: DVec3, vel: DVec3, life: u32 },
 }
@@ -2094,11 +2098,27 @@ impl Sim {
         self.fx.push((id, Fx::Fireball { pos, size, age: 0, life, spin }));
     }
 
-    /// A drone hit by air defence: a flash, pieces, and it falls burning.
-    fn shoot_down(&mut self, idx: usize, by: u32, missile: Option<u32>, out: &mut Out) {
+    /// A drone hit by the guns of system `by`.
+    fn shoot_down(&mut self, idx: usize, by: u32, missile: Option<u32>, out: &mut Out) -> Option<Outcome> {
+        let kind = self.sams.iter().find(|s| s.id == by).map_or(SamKind::Gepard, |s| s.kind);
+        let shell = kind.spec().gun.as_ref().map_or(5.0, |g| g.shell);
+        let at = self.drones[idx].pos;
+        self.shoot_down_by(idx, by, missile, Impact::gun(kind, at, shell), out)
+    }
+
+    /// A drone brought down by `imp` from system `by`: how it ends is rolled once (combat randomness, so a
+    /// detonation really means no ground impact), recorded with the kill, and drawn from the visual randomness
+    /// only. The kill is counted here and nowhere else.
+    fn shoot_down_by(&mut self, idx: usize, by: u32, missile: Option<u32>, imp: Impact, out: &mut Out) -> Option<Outcome> {
         if !self.drones[idx].alive() {
-            return;
+            return None;
         }
+        let dkind = self.drones[idx].kind;
+        let roll = self.rng.f();
+        let outcome = outcome::choose(dkind, &imp, roll);
+        let spec = dkind.spec();
+        // A broken-up target's warhead section may stay whole: it falls on as a wreck (and may go off on landing).
+        let keeps_warhead = outcome == Outcome::Breakup && !spec.decoy && spec.warhead > 0 && self.rng.chance(outcome::WARHEAD_SURVIVES);
         let sector = self.drones[idx].sector as usize;
         self.learn(sector, true);
         let until = self.tick + 70;
@@ -2106,33 +2126,72 @@ impl Sim {
             s.kill_view = Some((self.drones[idx].id, self.drones[idx].pos, until));
         }
         if let Some((i, s)) = self.sams.iter().enumerate().find(|(_, s)| s.id == by) {
-            let (drone, kind, pos) = (self.drones[idx].id, self.drones[idx].kind, self.drones[idx].pos);
-            let kill = record::EventKind::Kill { drone, kind, sam: by, sam_kind: s.kind, sam_index: i, missile };
+            let (drone, kind, pos) = (self.drones[idx].id, dkind, self.drones[idx].pos);
+            let kill = record::EventKind::Kill { drone, kind, sam: by, sam_kind: s.kind, sam_index: i, missile, outcome };
             self.log(pos, kill);
         }
         let d = &mut self.drones[idx];
+        let before = d.vel;
         d.flight = Flight::Falling;
         d.age = 0;
-        d.vel = d.vel * 0.6 + DVec3::new(0.0, 0.15, 0.0);
+        d.vel = match outcome {
+            Outcome::DisabledFalling => d.vel * 0.6 + DVec3::new(0.0, 0.15, 0.0),
+            _ => d.vel * 0.35 + DVec3::new(0.0, 0.1, 0.0),
+        };
         let pos = d.pos;
         let vel = d.vel;
         self.kills += 1;
         if let Some(s) = self.sams.iter_mut().find(|s| s.id == by) {
             s.kills += 1;
         }
-        // The look of the kill goes by the warhead it blew up (replays use the same).
-        let (size, life, gain) = record::kill_look(self.drones[idx].kind);
+        // The look of the kill goes by the warhead it blew up and by how it ended (replays use the same).
+        let (size, life, gain, sound) = outcome::look(dkind, outcome);
         self.fireball(pos, size as f64, life / 9);
-        out.particles("minecraft:explosion", pos, 0.6, DVec3::ZERO, 0.0, 4);
-        out.particles("minecraft:large_smoke", pos, 1.0, DVec3::ZERO, 0.06, 25);
-        out.particles("minecraft:firework", pos, 0.3, DVec3::ZERO, 0.35, 30);
-        out.sound("airdef:blast.air", pos, gain, 1.0 + self.vis.f() as f32 * 0.2);
-        for _ in 0..5 {
-            let id = fx_ident(&mut self.fx_next);
-            let v = vel + DVec3::new(self.vis.s(), self.vis.f() * 0.8, self.vis.s()) * 0.35;
-            let spin = DQuat::from_euler(glam::EulerRot::XYZ, self.vis.s() * 0.4, self.vis.s() * 0.4, self.vis.s() * 0.4);
-            self.fx.push((id, Fx::Debris { pos, vel: v, rot: DQuat::IDENTITY, spin, age: 0 }));
+        let pitch = 1.0 + self.vis.f() as f32 * 0.2;
+        match outcome {
+            Outcome::DisabledFalling => {
+                out.particles("minecraft:explosion", pos, 0.6, DVec3::ZERO, 0.0, 4);
+                out.particles("minecraft:large_smoke", pos, 1.0, DVec3::ZERO, 0.06, 25);
+                out.particles("minecraft:firework", pos, 0.3, DVec3::ZERO, 0.35, 30);
+                for _ in 0..5 {
+                    let id = fx_ident(&mut self.fx_next);
+                    let v = vel + DVec3::new(self.vis.s(), self.vis.f() * 0.8, self.vis.s()) * 0.35;
+                    let spin = DQuat::from_euler(glam::EulerRot::XYZ, self.vis.s() * 0.4, self.vis.s() * 0.4, self.vis.s() * 0.4);
+                    self.fx.push((id, Fx::Debris { pos, vel: v, rot: DQuat::IDENTITY, spin, age: 0 }));
+                }
+            }
+            Outcome::Breakup => {
+                out.particles("minecraft:explosion", pos, 0.8, DVec3::ZERO, 0.0, 3);
+                out.particles("minecraft:large_smoke", pos, 1.4, DVec3::ZERO, 0.08, 30);
+                out.particles("minecraft:firework", pos, 0.4, DVec3::ZERO, 0.3, 14);
+            }
+            Outcome::AirDetonation => {
+                out.particles("minecraft:flash", pos, 0.0, DVec3::ZERO, 0.0, 1);
+                out.particles("minecraft:explosion_emitter", pos, 0.8, DVec3::ZERO, 0.0, 2);
+                out.particles("minecraft:large_smoke", pos, size * 0.3, DVec3::new(0.0, 0.05, 0.0), 0.07, if self.shader { 20 } else { 40 });
+                out.particles("minecraft:firework", pos, 0.6, DVec3::ZERO, 0.5, 50);
+                // The shock arrives after the flash (`boom` sounds travel); the warhead's blast hurts what is near.
+                out.sound("airdef:boom.sonic", pos, 0.8, 1.2);
+                self.blast_damage(pos, 0, out);
+            }
         }
+        out.sound(sound, pos, gain, pitch);
+        let seed = self.vis.next();
+        let mut alive = self.fx.iter().filter(|(_, f)| matches!(f, Fx::Piece { .. })).count();
+        for p in outcome::pieces(seed, outcome, before) {
+            if alive + 1 > outcome::PIECES_MAX {
+                break;
+            }
+            let id = fx_ident(&mut self.fx_next);
+            let rot = DQuat::from_euler(glam::EulerRot::XYZ, self.vis.s(), self.vis.s(), self.vis.s());
+            self.fx.push((id, Fx::Piece { pos, vel: p.vel, rot, piece: p, age: 0 }));
+            alive += 1;
+        }
+        if outcome == Outcome::AirDetonation || (outcome == Outcome::Breakup && !keeps_warhead) {
+            // The main mass is gone: nothing falls to the ground and nothing goes off there.
+            self.drones.remove(idx);
+        }
+        Some(outcome)
     }
 
     // ------------------------------------------------ air defence
@@ -2486,7 +2545,7 @@ impl Sim {
         }
         for (t, by) in gun_hits {
             if let Some(i) = self.drones.iter().position(|d| d.id == t) {
-                self.shoot_down(i, by, None, out);
+                let _ = self.shoot_down(i, by, None, out);
             }
         }
         for i in 0..self.sams.len() {
@@ -2679,7 +2738,8 @@ impl Sim {
                 if let Some(t) = target.and_then(|t| self.drones.iter().position(|d| d.id == t)) {
                     self.drones[t].engaged = self.drones[t].engaged.saturating_sub(1);
                     if kill {
-                        self.shoot_down(t, sam, Some(mid), out);
+                        let (at, closing) = (self.drones[t].pos, (m.vel - self.drones[t].vel).length());
+                        let _ = self.shoot_down_by(t, sam, Some(mid), Impact::missile(m.kind, at, closing), out);
                     }
                 }
                 // A missile that lost its target frees it for others.
@@ -2730,6 +2790,20 @@ impl Sim {
                     let landed = ground.at(*pos, now).is_some_and(|g| pos.y <= g);
                     !landed && *age < 200
                 }
+                Fx::Piece { pos, vel, rot, piece, age } => {
+                    *age += 1;
+                    outcome::fly(pos, vel, piece.drag);
+                    *rot = piece.spin * *rot;
+                    out.model(id, "airdef:debris", *pos, *rot, piece.scale, false);
+                    if piece.burns {
+                        out.particles("minecraft:large_smoke", *pos, 0.1, DVec3::new(0.0, 0.03, 0.0), 0.01, 1);
+                        if *age % 3 == 0 {
+                            out.particles("minecraft:flame", *pos, 0.1, DVec3::ZERO, 0.01, 1);
+                        }
+                    }
+                    let landed = ground.at(*pos, now).is_some_and(|g| pos.y <= g);
+                    !landed && *age < piece.life
+                }
                 Fx::Tracer { pos, vel, life } => {
                     *pos += *vel;
                     vel.y -= 0.02;

airdef-mod/src/sim/outcome.rs

@@ -0,0 +1,356 @@
+//! What a kill does to the air target (#97): it falls burning on, it breaks up, or its warhead goes
+//! off in the air. The chances are game profiles, all here and nowhere else; they are not the real
+//! weapons' figures. The roll is combat randomness (a detonation means no ground impact), one draw
+//! per kill; everything drawn from it (pieces, sparks) is decoration and uses only the visual RNG.
+//! The outcome is recorded with the kill, so a replay shows it and never rolls again.
+use super::*;
+
+/// How an air target ended up when it was brought down.
+#[derive(Clone, Copy, PartialEq, Eq, Debug, Default)]
+pub enum Outcome {
+    /// Control lost: the burning hull falls on with what momentum it had. A recording without an
+    /// outcome (an old one) is read as this, which is what every kill used to be.
+    #[default]
+    DisabledFalling,
+    /// The airframe tears into several pieces; the warhead section may survive and fall on.
+    Breakup,
+    /// The warhead goes off in the air: a flash and a rain of debris, nothing left to hit the ground.
+    AirDetonation,
+}
+
+/// What brought the target down.
+#[derive(Clone, Copy, PartialEq, Eq, Debug)]
+pub enum KillCause {
+    /// Shells of this system's guns.
+    Gun(SamKind),
+    Missile(MissileKind),
+}
+
+/// A hit, as far as the outcome is concerned.
+#[derive(Clone, Copy, Debug)]
+pub struct Impact {
+    pub cause: KillCause,
+    /// Game energy of the hit (see `energy_of`).
+    pub energy: f64,
+    pub at: DVec3,
+    /// Closing speed, blocks a tick.
+    pub rel_speed: f64,
+}
+
+impl Impact {
+    pub fn gun(sam: SamKind, at: DVec3, rel_speed: f64) -> Self {
+        Impact { cause: KillCause::Gun(sam), energy: energy_of(KillCause::Gun(sam)), at, rel_speed }
+    }
+    pub fn missile(kind: MissileKind, at: DVec3, rel_speed: f64) -> Self {
+        Impact { cause: KillCause::Missile(kind), energy: energy_of(KillCause::Missile(kind)), at, rel_speed }
+    }
+}
+
+// ---- the profiles: the one place to tune ------------------------------------------------------
+
+/// Game energy of one hit: a shell is small, an interceptor's warhead is big.
+pub fn energy_of(cause: KillCause) -> f64 {
+    match cause {
+        KillCause::Gun(SamKind::Gepard) => 0.15,
+        KillCause::Gun(_) => 0.13,
+        KillCause::Missile(m) => match m {
+            MissileKind::Pac3 => 1.0,
+            MissileKind::M57e6 => 0.5,
+            MissileKind::M48n6 => 1.2,
+            MissileKind::M77n6 => 1.6,
+            MissileKind::IrisT => 0.7,
+            MissileKind::Amraam => 0.6,
+            MissileKind::M9m317 => 0.8,
+            MissileKind::M9m338 => 0.7,
+            // Rams: a lot of speed, no warhead to speak of.
+            MissileKind::P1sun => 0.25,
+        },
+    }
+}
+
+/// How much a target takes before it comes apart: size, then what it carries.
+pub fn toughness(kind: DroneKind) -> f64 {
+    let s = kind.spec();
+    0.2 + 0.2 * s.scale + 0.03 * s.warhead as f64
+}
+
+/// Chance of an air detonation: nothing without a warhead, rare for shells, likely when a strong
+/// interceptor meets a small target.
+const DET_BASE: f64 = 0.04;
+const DET_SLOPE: f64 = 0.32;
+const DET_FLOOR: f64 = 0.03;
+const DET_CEIL: f64 = 0.75;
+/// Of the rest, the share that breaks up instead of falling on.
+const BREAK_BASE: f64 = 0.12;
+const BREAK_SLOPE: f64 = 0.3;
+const BREAK_CEIL: f64 = 0.8;
+/// A broken-up target whose warhead section stays whole and falls on (and may cook off on landing).
+pub const WARHEAD_SURVIVES: f64 = 0.3;
+
+/// The relative strength of the hit against the target.
+pub fn ratio(kind: DroneKind, imp: &Impact) -> f64 {
+    let speed = (0.8 + 0.05 * imp.rel_speed).clamp(0.8, 1.2);
+    imp.energy * speed / toughness(kind)
+}
+
+/// (chance of an air detonation, chance of a breakup) of a hit on `kind`; the rest falls on.
+pub fn odds(kind: DroneKind, imp: &Impact) -> (f64, f64) {
+    let s = kind.spec();
+    let r = ratio(kind, imp);
+    let det = if s.decoy || s.warhead == 0 { 0.0 } else { (DET_BASE + DET_SLOPE * (r - 0.4)).clamp(DET_FLOOR, DET_CEIL) };
+    let share = (BREAK_BASE + BREAK_SLOPE * r).clamp(0.0, BREAK_CEIL);
+    (det, (1.0 - det) * share)
+}
+
+/// The outcome for a roll of 0..1.
+pub fn choose(kind: DroneKind, imp: &Impact, roll: f64) -> Outcome {
+    let (det, brk) = odds(kind, imp);
+    if roll < det {
+        Outcome::AirDetonation
+    } else if roll < det + brk {
+        Outcome::Breakup
+    } else {
+        Outcome::DisabledFalling
+    }
+}
+
+/// The look of a kill by the target's warhead and the outcome: (fireball radius, ticks it burns,
+/// loudness, sound). A bare decoy pops; a detonation lights the sky. The live raid and its replay
+/// both take it from here.
+pub fn look(kind: DroneKind, outcome: Outcome) -> (f32, u32, f32, &'static str) {
+    let w = kind.spec().warhead.min(8) as f32;
+    let size = 3.5 * (0.85 + 0.12 * w);
+    let life = (8 + (w as u32) / 2) * 9;
+    let gain = 1.0 + 0.06 * w;
+    match outcome {
+        Outcome::DisabledFalling => (size, life, gain, "airdef:blast.air"),
+        Outcome::Breakup => (size * 0.9, life, gain * 0.9, "airdef:blast.medium"),
+        Outcome::AirDetonation => (size * 1.9, life * 8 / 5, gain * 1.5, "airdef:blast.big"),
+    }
+}
+
+// ---- pieces -----------------------------------------------------------------------------------
+
+/// Most pieces alive at once; a mass battle thins them out.
+pub const PIECES_MAX: usize = 320;
+/// Longest a piece lives, ticks (a replay's pieces end here too).
+pub const PIECE_LIFE: u32 = 110;
+
+/// One piece thrown off: its own velocity, spin, size, drag and life.
+#[derive(Clone, Copy, Debug)]
+pub struct Piece {
+    pub vel: DVec3,
+    pub spin: DQuat,
+    pub scale: f64,
+    pub drag: f64,
+    pub life: u32,
+    /// Trails smoke while it falls.
+    pub burns: bool,
+}
+
+/// The pieces of an outcome from `seed` (decorative randomness only), moving on with `base` (the
+/// target's velocity). None for a fall.
+pub fn pieces(seed: u64, outcome: Outcome, base: DVec3) -> Vec<Piece> {
+    let (n, speed, size, life) = match outcome {
+        Outcome::DisabledFalling => return Vec::new(),
+        Outcome::Breakup => (7, 0.35, 1.0, 70),
+        Outcome::AirDetonation => (12, 0.8, 0.8, 50),
+    };
+    let mut rng = Rng::new(seed ^ 0x9e37_79b9_7f4a_7c15);
+    (0..n)
+        .map(|_| {
+            let dir = DVec3::new(rng.s(), rng.s() * 0.8 + 0.2, rng.s()).normalize_or(DVec3::Y);
+            let v = base * if outcome == Outcome::Breakup { 0.55 } else { 0.3 } + dir * speed * (0.4 + 0.8 * rng.f());
+            let spin = DQuat::from_euler(glam::EulerRot::XYZ, rng.s() * 0.5, rng.s() * 0.5, rng.s() * 0.5);
+            Piece {
+                vel: v,
+                spin,
+                scale: size * (0.5 + 0.8 * rng.f()),
+                drag: 0.96 + 0.025 * rng.f(),
+                life: (life as f64 * (0.6 + 0.4 * rng.f())) as u32,
+                burns: rng.chance(0.6),
+            }
+        })
+        .collect()
+}
+
+/// One tick of a piece's flight: gravity, then drag (the replays and the live raid move the same).
+pub fn fly(pos: &mut DVec3, vel: &mut DVec3, drag: f64) {
+    vel.y -= 0.05;
+    *vel *= drag;
+    *pos += *vel;
+}
+
+/// Where a piece is `age` ticks after it was thrown from `at`, as a pure function (for replays).
+pub fn piece_at(at: DVec3, p: &Piece, age: u32) -> DVec3 {
+    let (mut pos, mut vel) = (at, p.vel);
+    for _ in 0..age.min(p.life) {
+        fly(&mut pos, &mut vel, p.drag);
+    }
+    pos
+}
+
+/// How a piece is turned `age` ticks after it was thrown (a replay's, from the start).
+pub fn piece_rot(p: &Piece, age: u32) -> DQuat {
+    let mut rot = DQuat::IDENTITY;
+    for _ in 0..age.min(p.life) {
+        rot = p.spin * rot;
+    }
+    rot
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn shares(kind: DroneKind, imp: Impact, seeds: u64) -> [u32; 3] {
+        let mut n = [0u32; 3];
+        let mut rng = Rng::new(97);
+        for _ in 0..seeds {
+            let roll = rng.f();
+            n[match choose(kind, &imp, roll) {
+                Outcome::DisabledFalling => 0,
+                Outcome::Breakup => 1,
+                Outcome::AirDetonation => 2,
+            }] += 1;
+        }
+        n
+    }
+
+    // #97: the profiles are tendencies, not laws: shells mostly leave a falling hull, a strong interceptor
+    // against a small target often detonates it, and everything still can happen.
+    #[test]
+    fn outcomes_follow_the_weapon_and_the_target() {
+        let at = DVec3::ZERO;
+        let gun = shares(DroneKind::Shahed, Impact::gun(SamKind::Gepard, at, 10.0), 4000);
+        assert!(gun[0] > 2400 && gun[2] < 400, "gun against a Shahed: {gun:?}");
+        assert!(gun[1] > 0 && gun[2] > 0, "not a law: some break up, a few go off: {gun:?}");
+        let strong = shares(DroneKind::Shahed, Impact::missile(MissileKind::M77n6, at, 6.0), 4000);
+        assert!(strong[2] > 2000, "a strong interceptor against a small target: {strong:?}");
+        let weak = shares(DroneKind::Shahed, Impact::missile(MissileKind::M57e6, at, 5.0), 4000);
+        assert!(weak[2] < strong[2] && weak[2] > gun[2], "in between: {weak:?}");
+        // A big missile is tougher than a small drone for the same interceptor.
+        let big = shares(DroneKind::Iskander, Impact::missile(MissileKind::Pac3, at, 6.0), 4000);
+        let small = shares(DroneKind::Shahed, Impact::missile(MissileKind::Pac3, at, 6.0), 4000);
+        assert!(big[2] < small[2], "{big:?} {small:?}");
+        // Without a warhead nothing goes off: a decoy or a bus breaks up or falls.
+        for kind in [DroneKind::Gerbera, DroneKind::Oreshnik] {
+            assert_eq!(shares(kind, Impact::missile(MissileKind::M77n6, at, 6.0), 2000)[2], 0, "{kind:?}");
+        }
+    }
+
+    fn kill(seed: u64, shader: bool, imp: impl Fn(DVec3) -> Impact) -> (Outcome, usize, u64) {
+        let mut sim = Sim::new(seed);
+        sim.shader = shader;
+        let mut out = Out::default();
+        let sam = sim.id();
+        sim.sams.push(Sam::new(sam, SamKind::Patriot, DVec3::new(0.0, 70.0, 0.0), 0.0));
+        sim.add_drone(DroneKind::Shahed, DVec3::new(0.0, 120.0, 300.0), DVec3::X, DVec3::new(900.0, 70.0, 0.0));
+        let at = sim.drones[0].pos;
+        let o = sim.shoot_down_by(0, sam, None, imp(at), &mut out).unwrap();
+        (o, sim.drones.len(), sim.rng.state())
+    }
+
+    // #97: the roll is combat randomness: the same with graphics on and off, and the drawing never moves it.
+    #[test]
+    fn the_outcome_is_the_same_with_graphics_on_and_off() {
+        for seed in 1..40 {
+            let strong = |at| Impact::missile(MissileKind::M77n6, at, 6.0);
+            assert_eq!(kill(seed, true, strong), kill(seed, false, strong), "seed {seed}");
+            let gun = |at| Impact::gun(SamKind::Gepard, at, 10.0);
+            assert_eq!(kill(seed, true, gun), kill(seed, false, gun), "seed {seed}");
+        }
+    }
+
+    // #97: a detonated warhead is spent: no wreck falls, so no second blast on landing; the kill counts once.
+    #[test]
+    fn a_detonated_target_does_no_ground_damage_and_counts_once() {
+        let mut found = 0;
+        for seed in 1..60 {
+            let mut sim = Sim::new(seed);
+            sim.damage = true;
+            let mut out = Out::default();
+            let mut ground = Ground::default();
+            ground.answer((-50..50).flat_map(|x| (-50..400).map(move |z| (x, z, 70))).collect(), 0);
+            let sam = sim.id();
+            sim.sams.push(Sam::new(sam, SamKind::Patriot, DVec3::new(0.0, 70.0, 0.0), 0.0));
+            sim.add_drone(DroneKind::Shahed, DVec3::new(0.0, 120.0, 300.0), DVec3::X, DVec3::new(900.0, 70.0, 0.0));
+            let at = sim.drones[0].pos;
+            let o = sim.shoot_down_by(0, sam, Some(5), Impact::missile(MissileKind::M77n6, at, 6.0), &mut out).unwrap();
+            if o != Outcome::AirDetonation {
+                continue;
+            }
+            found += 1;
+            assert!(sim.drones.is_empty(), "the main mass is gone");
+            assert_eq!((sim.kills, sim.hits, sim.crashes), (1, 0, 0));
+            assert_eq!(sim.sams[0].kills, 1);
+            let mut cmds = out.commands.len();
+            for _ in 0..400 {
+                sim.tick += 1;
+                let mut o = Out::default();
+                sim.step_drones(&mut ground, None, &mut o);
+                sim.step_fx(&mut ground, &mut o);
+                cmds += o.commands.len();
+                assert!(o.sounds.iter().all(|s| !s.0.starts_with("airdef:blast")), "a second blast");
+            }
+            assert_eq!(cmds, 0, "no primed TNT for the land from a detonated warhead");
+            assert_eq!(sim.kills, 1);
+        }
+        assert!(found >= 10, "{found} detonations in 59 seeds");
+    }
+
+    // #97: a breakup throws pieces that have a life: they expire, and the number alive is bounded in a mass battle.
+    #[test]
+    fn pieces_expire_and_a_mass_battle_keeps_them_bounded() {
+        let mut sim = Sim::new(3);
+        let mut out = Out::default();
+        let mut ground = Ground::default();
+        for i in 0..150 {
+            let sam = sim.id();
+            sim.sams.push(Sam::new(sam, SamKind::Patriot, DVec3::new(f64::from(i) * 500.0, 70.0, 0.0), 0.0));
+            sim.add_drone(DroneKind::Shahed, DVec3::new(f64::from(i) * 500.0, 400.0, 300.0), DVec3::X, DVec3::new(9e5, 70.0, 0.0));
+            let at = sim.drones.last().unwrap().pos;
+            let idx = sim.drones.len() - 1;
+            let _ = sim.shoot_down_by(idx, sam, None, Impact::missile(MissileKind::M77n6, at, 6.0), &mut out);
+        }
+        let pieces = |s: &Sim| s.fx.iter().filter(|(_, f)| matches!(f, Fx::Piece { .. })).count();
+        let n = pieces(&sim);
+        assert!(n > 0 && n <= PIECES_MAX, "{n} pieces");
+        for _ in 0..PIECE_LIFE + 1 {
+            sim.tick += 1;
+            sim.step_fx(&mut ground, &mut Out::default());
+        }
+        assert_eq!(pieces(&sim), 0, "pieces expire");
+    }
+
+    // #97: a breakup either keeps the warhead section (a wreck still falling, which may go off on landing by the
+    // existing roll) or leaves nothing to fall.
+    #[test]
+    fn a_breakup_keeps_the_warhead_section_only_sometimes() {
+        let (mut kept, mut gone) = (0, 0);
+        for seed in 1..200 {
+            let (o, drones, _) = kill(seed, true, |at| Impact::missile(MissileKind::M57e6, at, 5.0));
+            if o == Outcome::Breakup {
+                if drones == 1 {
+                    kept += 1;
+                } else {
+                    gone += 1;
+                }
+            }
+        }
+        assert!(kept > 0 && gone > kept, "kept {kept} gone {gone}");
+    }
+
+    // #97: a flight of a piece is a pure function of its age (so a replay moves it as the raid did).
+    #[test]
+    fn a_pieces_flight_is_the_same_stepped_or_computed() {
+        let ps = pieces(5, Outcome::AirDetonation, DVec3::new(0.5, 0.0, 0.2));
+        assert!(!ps.is_empty() && pieces(5, Outcome::DisabledFalling, DVec3::ZERO).is_empty());
+        let (mut pos, mut vel) = (DVec3::new(1.0, 100.0, 2.0), ps[0].vel);
+        for _ in 0..20 {
+            fly(&mut pos, &mut vel, ps[0].drag);
+        }
+        assert!(pos.distance(piece_at(DVec3::new(1.0, 100.0, 2.0), &ps[0], 20)) < 1e-9);
+        assert!(ps.iter().all(|p| p.life <= PIECE_LIFE));
+    }
+}

airdef-mod/src/sim/record.rs

@@ -168,8 +168,9 @@ pub struct Track {
 
 #[derive(Clone, Copy, PartialEq, Debug)]
 pub enum EventKind {
-    /// A drone shot down: by which system (its index then), with a missile or the guns.
-    Kill { drone: u32, kind: DroneKind, sam: u32, sam_kind: SamKind, sam_index: usize, missile: Option<u32> },
+    /// A drone shot down: by which system (its index then), with a missile or the guns, and how it ended
+    /// (rolled once, live; a replay reads it and never rolls).
+    Kill { drone: u32, kind: DroneKind, sam: u32, sam_kind: SamKind, sam_index: usize, missile: Option<u32>, outcome: Outcome },
     /// A drone's warhead went off where it aimed: at an object, a system, or the land.
     Hit { drone: u32, kind: DroneKind, power: u32, object: Option<usize>, sam: Option<(SamKind, usize)> },
     /// A system destroyed.
@@ -331,8 +332,8 @@ pub struct ReplayFire {
 /// The look of an interception by the drone's warhead: (fireball radius, ticks it burns, loudness).
 /// A bare decoy pops; a big warhead lights the sky. The same in the live raid and its replay.
 pub fn kill_look(kind: DroneKind) -> (f32, u32, f32) {
-    let w = kind.spec().warhead.min(8) as f32;
-    (3.5 * (0.85 + 0.12 * w), (8 + (w as u32) / 2) * 9, 1.0 + 0.06 * w)
+    let (size, life, gain, _) = outcome::look(kind, Outcome::DisabledFalling);
+    (size, life, gain)
 }
 
 /// A blast's look for an event: (fireball radius, ticks it burns). The live blasts use the same.
@@ -340,8 +341,8 @@ pub fn blast_spec(kind: EventKind) -> (f32, u32) {
     const SIZE: [f32; 5] = [2.5, 4.5, 7.0, 10.0, 13.0];
     const LIFE: [u32; 5] = [11, 11, 18, 22, 26];
     match kind {
-        EventKind::Kill { kind, .. } => {
-            let (size, life, _) = kill_look(kind);
+        EventKind::Kill { kind, outcome, .. } => {
+            let (size, life, _, _) = outcome::look(kind, outcome);
             (size, life)
         }
         EventKind::Hit { power, .. } | EventKind::Crash { power, .. } => {
@@ -581,6 +582,7 @@ impl Sim {
 
     /// Draws the recording's drones and interceptors as they were at `t`, as ghosts: ids from `base`.
     pub fn draw_ghosts(&self, rec: &Recording, t: f64, base: u32, out: &mut Out) {
+        let base_id = base;
         for (k, tr) in rec.tracks.iter().enumerate() {
             let Some(pos) = tr.at(rec.origin, t) else { continue };
             let dir = tr.dir(rec.origin, t);
@@ -660,6 +662,31 @@ impl Sim {
                 out.particles("minecraft:large_smoke", f.at + DVec3::Y, 0.8, DVec3::new(0.0, 0.1, 0.0), 0.03, 1 + (smoke * 2.0) as u32);
             }
         }
+        // The pieces a breakup or an air detonation threw off, from the recorded outcome (never a new roll): the same
+        // pieces the live raid made, moved by the same flight, a pure function of the time.
+        for (k, e) in rec.events.iter().enumerate() {
+            let EventKind::Kill { drone, outcome, .. } = e.kind else { continue };
+            let age = t - e.at as f64;
+            if outcome == Outcome::DisabledFalling || !(0.0..outcome::PIECE_LIFE as f64).contains(&age) {
+                continue;
+            }
+            let base = rec
+                .track(drone)
+                .and_then(|tr| Some((tr.at(rec.origin, e.at as f64)? - tr.at(rec.origin, e.at as f64 - STEP as f64)?) / STEP as f64))
+                .unwrap_or(DVec3::ZERO);
+            let seed = (k as u64).wrapping_mul(0x2545_f491_4f6c_dd1d) ^ e.at as u64;
+            for (n, p) in outcome::pieces(seed, outcome, base).iter().enumerate() {
+                if age as u32 >= p.life {
+                    continue;
+                }
+                let at = outcome::piece_at(e.pos, p, age as u32);
+                let id = base_id + 0x0060_0000 + (k as u32 * 16 + n as u32) * PARTS;
+                out.model(id, "airdef:debris", at, outcome::piece_rot(p, age as u32), p.scale, false);
+                if p.burns && (age as u32) % 3 == 0 {
+                    out.particles("minecraft:large_smoke", at, 0.1, DVec3::new(0.0, 0.03, 0.0), 0.01, 1);
+                }
+            }
+        }
         // Blasts: with the shader effects on, the post pass and the HD lights draw them from
         // `replay_blasts` (the same as the live ones); the models are the fallback without them.
         if self.shader {
@@ -793,4 +820,46 @@ mod tests {
         assert_eq!(r.world_tick(50.0), Some(1040 + 10));
         assert_eq!(r.world_tick(70.0), Some(1100 + 10));
     }
+
+    // #97: the kill's outcome is a recorded fact: a replay draws the pieces of that outcome and rolls nothing;
+    // an event without one (an old recording) is the plain fall it always was.
+    #[test]
+    fn a_replay_shows_the_recorded_outcome() {
+        let mut sim = Sim::new(5);
+        sim.rec = Some(Recording::new(1, &sim));
+        let sam = sim.id();
+        sim.sams.push(Sam::new(sam, SamKind::Patriot, DVec3::new(0.0, 70.0, 0.0), 0.0));
+        sim.add_drone(DroneKind::Shahed, DVec3::new(0.0, 120.0, 300.0), DVec3::X, DVec3::new(900.0, 70.0, 0.0));
+        let at = sim.drones[0].pos;
+        let live = sim.shoot_down_by(0, sam, None, Impact::missile(MissileKind::M77n6, at, 6.0), &mut Out::default()).unwrap();
+        let rec = sim.rec.take().unwrap();
+        let recorded = rec.events.iter().find_map(|e| if let EventKind::Kill { outcome, .. } = e.kind { Some(outcome) } else { None });
+        assert_eq!(recorded, Some(live), "the live outcome is what was recorded");
+        let pieces = |rec: &Recording, t: f64| {
+            let mut out = Out::default();
+            sim.draw_ghosts(rec, t, 0x5000_0000, &mut out);
+            out.models.iter().filter(|m| m.name == "airdef:debris").count()
+        };
+        let at_tick = rec.events[0].at as f64;
+        // The same frame twice is the same (a pure function of the time), and the pieces are the outcome's.
+        let mut forced = Recording { events: rec.events.clone(), ..Recording::blank(200) };
+        for (outcome, want) in [(Outcome::AirDetonation, true), (Outcome::Breakup, true), (Outcome::DisabledFalling, false)] {
+            if let EventKind::Kill { outcome: o, .. } = &mut forced.events[0].kind {
+                *o = outcome;
+            }
+            assert_eq!(pieces(&forced, at_tick + 5.0), pieces(&forced, at_tick + 5.0));
+            assert_eq!(pieces(&forced, at_tick + 5.0) > 0, want, "{outcome:?}");
+            assert_eq!(pieces(&forced, at_tick + f64::from(outcome::PIECE_LIFE) + 1.0), 0, "the pieces are gone in time");
+        }
+        // Its flash and sound are the outcome's too.
+        let spec = |o| {
+            let mut e = rec.events[0];
+            if let EventKind::Kill { outcome, .. } = &mut e.kind {
+                *outcome = o;
+            }
+            blast_spec(e.kind)
+        };
+        assert!(spec(Outcome::AirDetonation).0 > spec(Outcome::DisabledFalling).0);
+        assert_eq!(spec(Outcome::default()).0, kill_look(DroneKind::Shahed).0, "an old recording looks as it did");
+    }
 }

airdef-mod/src/sim/regress.rs

@@ -473,7 +473,7 @@ fn pending_exact_answer_does_not_let_the_fuse_kill_through_a_wall() {
                 ground.world.answer(answers, sim.tick);
             }
         }
-        (first, sim.kills, sim.drones[0].alive())
+        (first, sim.kills, sim.drones.first().is_some_and(Drone::alive))
     };
     for seed in 1..=10 {
         // Just behind the wall, inside the fuse's reach of a missile held at its face.