Movement & collision

1The pipeline

2The state machine is a script

action/script/c0000.hks is compiled Havok Script. DSLuaDecompiler turns it into 15,439 lines, 977 functions of Lua. Every frame, the graph calls <State>_onUpdate() for each active state. The script reads engine state with env(id, …), writes graph variables, fires transitions with ExecEvent("W_…"), and calls engine actions with act(id, …). AttackCommonFunction shows the priority of everything: passive actions, evasion, guard, items, magic, weapon arts, the next attack, weapon change, then movement and quick turns.

From an event to a clip

ExecEvent("W_RollingMedium") names a behaviour event, not a clip. The graph (c0000.behbnd: 7,026 clip generators, 2,589 FromSoft CustomManualSelectorGenerators, 1,091 states, 1,267 event names) maps it. Our graph reader lists it all:

Each event's transition names its crossfade: 0.1 s for rolls, damage and guard reactions; 1/6 s for jumps; FromSoft's own "DefaultTransition" uses the clip's TAE Blend event (attacks 0.2-0.33 s).

3Locomotion

• The engine sets MoveSpeedLevel from the stick and sprint: 0 idle, ~1 walk, ~2 dash. The blend uses a smoothed MoveSpeedLevelReal: ConvergeValue, a linear approach at +3/s (walk), +4.5/s (dash; the file defines 6, then redefines 4.5) and −3/s down.
• Above 1.6 you're dashing: R1 and R2 become dash attacks, and only then can you jump (SPEED_ENABLE_JUMP).
• Sprinting drains 1 stamina every 0.065 s. At empty, SpEffect 100020 caps the stick at a run for 2 s.
• Equip load changes which roll plays, not a speed multiplier.

Locked on, the graph picks one directional clip by MoveDirection; there's no 2-D blend. The script sets the "4-direction move thresholds" (60, 45, 60, 60). A locked-on dash releases the angle lock. Rolls turn to the target at once and pick a direction by RollingAngle. Lock-on range is 15 m (LockCamParam), 9 or 5 m in the dark.

Stops and turns: letting go at ≤ 0.35 goes straight to idle; ≤ 1 plays a run stop by direction; above that, W_DashStop (0.65 m of slide), from which a stick pushed past 90° plays a 180° dash turn whose root motion turns you while sliding.

4Rolls, backsteps and jumps

The medium rolls (1.83 s) share their TAE windows: flag 8 Invincible 0-0.533 s (16 frames of i-frames), flag 7 no turning 0.1-0.7 s, and flag 11 "stick may cancel" from 0.733 s. Distances: light 5.07 m, medium 4.45, heavy 3.31. Costs: roll 16 stamina, backstep 11, jump 16 (26 / 18 / 26 when overweight).

R1 in the air comes out on landing as the rolling R1, and R2 as the second heavy: the RH-attack window opens as the jump lands. The plunging attack starts once a fall is 2 m deep and R1 is pressed. Its clips carry flag 50, so the plunger falls through the enemy's capsule instead of standing on its head.

5TAE flags: the physics switchboard

Plus event types 224 SetTurnSpeed, 236 RootMotionReduction (0.8 → 0.7 → 0.5 through a jump) and 300 the jump tables. These carry most of DS3's "feel".

6The body: Havok's character proxy

Characters aren't rigid bodies. Each is a Havok hknpCharacterProxy, a kinematic capsule moved by a shape-cast-and-slide solver, wrapped as NS_SPRJ::CsHkCharacterProxy. The parameters were read off the stack frame of the creation function 0x140dda1c0, with Havok's own descriptions, which are embedded in the exe exe:

A character can have two proxies: one against characters and a second, with a different capsule, against the map. The second exists only when NpcParam's subHit size differs. After integrating, the closest upward-facing contact becomes the ground: its normal, and its hit material from body + shape key. The module keeps the last grounded position (+0x170, the fall-height reference) and air time.

Who pushes whom isn't traced. Ours lets a character be stopped only by characters at least as heavy, so the player can't shove hollows about but hollows push the player guess. Corpses block nobody.

7Falling and fall damage

Fall damage is engine code, on landing, before the script looks exe. For players (0x140634bc0): 0 under 5 m, all of max HP from 20 m, else max HP × CalcCorrectGraph 210 (height → %: 5/8/12/16/20 m → 8/15/50/90/100 %) × 211 (equip load) × 212 (VIT) × 213 (DEX) × SpEffects. The Knight takes ×1.32: 53 HP at 5.4 m, 219 at 10.4 m, all of it from about 14.6 m. Enemies: (h/15)^1.8 × (100 − fallDamageDamp) %.

8Bonfires, items, ladders, camera, keys