Missiles: authentic dsrm smoke trail + torso aim (placeholder tracer removed)

The "white lines toward the feet" report: the LAUNCHES are authentic (the
mech's real MissileLauncher/ProjectileWeapon roster subsystems firing on
their own recharge cadence -- that's the every-Nth-shot rhythm), but the
visual was the bring-up 3-segment beam tracer, and the aim point was the
victim's ORIGIN (ground level between the feet).

- Trail: per-frame puffs of the AUTHENTIC dsrm effect (psfx 0, "the lrm
  smoke trail") along the flight path, frame-oriented so the smoke streams
  behind the round (its .PFX velocities are +Z = backward); the round itself
  is a short hot streak.  New BTPfxTrailPuff spawns slot particles directly
  at a moving point (no emitter instance).
- Aim: the resolved target point lifts to torso height (the beams already
  converged there) -- impacts now cyl-resolve to body zones instead of
  diving at the feet/legs.

Follow-up noted: the round MESHES (BULLET/LRMS.BGF ship) for a true
model-per-projectile look.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

engine/MUNGA_L4/L4VIDEO.cpp

@@ -546,6 +546,36 @@ void BTStartPfx(int effect_number, float x, float y, float z)
 	BTStartPfxFrame(effect_number, x, y, z, 0, 0, 0);
 }
 
+// Spawn a few particles of a slot's effect DIRECTLY at a moving point (no
+// emitter instance) -- the per-frame projectile SMOKE TRAIL (psfx 0 = dsrm,
+// "the lrm smoke trail": its velocities stream +Z = BEHIND the round, so the
+// frame is built with local +Z = the flight's backward direction).
+static void BTPfxSpawn(const BTPfxEmitter &e);		// defined below
+void BTPfxTrailPuff(int effect_number, float x, float y, float z,
+	float backx, float backy, float backz, int count)
+{
+	if (effect_number < 0 || effect_number >= BT_PFX_SLOTS)
+		return;
+	const BTPfxDef &d = gBTPfxDefs[effect_number];
+	if (!d.valid)
+		return;
+	BTPfxEmitter e;					// transient -- used only as the spawn context
+	e.def = &d;
+	e.pos = D3DXVECTOR3(x, y, z);
+	D3DXVECTOR3 az(backx, backy, backz);
+	if (D3DXVec3LengthSq(&az) < 1e-6f)
+		az = D3DXVECTOR3(0, 0, 1);
+	D3DXVec3Normalize(&az, &az);
+	D3DXVECTOR3 up(0, 1, 0);
+	if (fabsf(az.y) > 0.99f) up = D3DXVECTOR3(1, 0, 0);
+	D3DXVECTOR3 ax; D3DXVec3Cross(&ax, &up, &az); D3DXVec3Normalize(&ax, &ax);
+	D3DXVECTOR3 ay; D3DXVec3Cross(&ay, &az, &ax);
+	e.ax = ax; e.ay = ay; e.az = az;
+	e.emitAccum = 0.0f; e.issued = 0; e.active = 0;
+	for (int i = 0; i < count; ++i)
+		BTPfxSpawn(e);
+}
+
 static void BTPfxSpawn(const BTPfxEmitter &e)
 {
 	const BTPfxDef &d = *e.def;

game/reconstructed/mech4.cpp

@@ -768,6 +768,12 @@ void
 		target = gEnemyMech;
 		tpos = ((Mech *)gEnemyMech)->localOrigin.linearPosition;
 	}
+	// AIM at the torso, not the feet: every target-position source here is the
+	// victim's ORIGIN (ground level between the feet) -- the beams already
+	// converge at chest height; missiles must too, or they visibly dive at the
+	// target's feet and the cylinder resolves leg zones for every hit.
+	if (target != 0)
+		tpos.y += kMuzzleHeight;
 	Vector3D d;
 	d.x = tpos.x - mz.x; d.y = tpos.y - mz.y; d.z = tpos.z - mz.z;
 	Scalar len = (Scalar)sqrtf(d.x*d.x + d.y*d.y + d.z*d.z);
@@ -804,14 +810,17 @@ static void
 		Scalar step = p.speed * dt;
 		p.pos.x += p.dir.x*step; p.pos.y += p.dir.y*step; p.pos.z += p.dir.z*step;
 		p.traveled += step;
-		// Missile look: a short smoky exhaust trail (behind) + a bright warm body + a
-		// hot flame tip, so it reads as a projectile rather than a thin laser line.
+		// AUTHENTIC missile look: the round is a short hot streak, and the trail
+		// is the real dsrm smoke-trail effect (psfx 0, "the lrm smoke trail")
+		// puffed along the flight path each frame with local +Z = backward (the
+		// .PFX's velocities stream the smoke behind the round).  This replaces
+		// the old 3-segment white tracer lines (a bring-up placeholder).
 		Vector3D bd = p.dir;
-		Point3D tail; tail.x = prev.x - bd.x*8.0f; tail.y = prev.y - bd.y*8.0f; tail.z = prev.z - bd.z*8.0f;
-		Point3D tip;  tip.x  = p.pos.x + bd.x*2.0f; tip.y  = p.pos.y + bd.y*2.0f; tip.z  = p.pos.z + bd.z*2.0f;
-		BTPushBeam(tail.x, tail.y, tail.z, prev.x, prev.y, prev.z,   0x00804020u, 0.20f, 3.2f);	// dim smoke trail
-		BTPushBeam(prev.x, prev.y, prev.z, p.pos.x, p.pos.y, p.pos.z, 0x00FF6010u, 0.15f, 2.6f);	// orange body
-		BTPushBeam(p.pos.x, p.pos.y, p.pos.z, tip.x, tip.y, tip.z,    0x00FFF0C0u, 0.15f, 1.4f);	// hot flame tip
+		BTPushBeam(prev.x, prev.y, prev.z, p.pos.x, p.pos.y, p.pos.z, 0x00FFB040u, 0.10f, 0.9f);	// the round (hot streak)
+		{
+			extern void BTPfxTrailPuff(int, float, float, float, float, float, float, int);
+			BTPfxTrailPuff(0, prev.x, prev.y, prev.z, -bd.x, -bd.y, -bd.z, 2);
+		}
 
 		Scalar dx = p.targetPos.x - p.pos.x, dy = p.targetPos.y - p.pos.y, dz = p.targetPos.z - p.pos.z;
 		if (dx*dx + dy*dy + dz*dz < (10.0f*10.0f) || p.traveled >= p.range)