Documentation Locomotion Framework

Locomotion Framework animates a third-person character: walking, running, stopping, turning around, jumping, climbing over an obstacle, drawing a weapon, aiming. You wire nothing: you file your animations into a grid, and the plugin picks the right one at the right moment.

The plugin is replicated: your characters stay in sync in multiplayer, host and client alike, with no extra network setup on your part.

The one idea to remember

The whole plugin fits in two grids, drawn the same way and read the same way: a cell is always where its row and its column meet, a click opens it, a right-click offers what can be done with it.

The first one says who your character is. One row per profile — bare hands, rifle, sword — and one column per state — standing, crouched. A cell is your character in that particular situation: the rifle while crouched.

The second one lives inside a profile and says what it plays. Columns are gaits — Idle, Walk, Run, Sprint. Rows are moments — the cycle, the start, the stop, the turn. A cell is, here again, where the two meet: “what my character plays when it is running and comes to a stop”.

The second one is what you will open right away: a new character has a single profile, and as long as you add neither a weapon nor a posture the first table fits in one cell. You fill in the cells you need; an empty cell plays nothing and breaks nothing. That holds from the first page of this documentation to the last.

What you need

• Unreal Engine 5.8.
• A character: a Skeletal Mesh and its skeleton. No particular rig is required.
• Animations. At the very least an idle and a run cycle — the rest can be added whenever you want.
• No C++: the plugin ships compiled, a Blueprint project is enough.

1. 1On the plugin’s FAB page, click “Add to My Library”. The plugin joins your Epic library.
2. 2Open the Epic Games Launcher, Unreal Engine tab then Library. The plugin appears at the bottom, under “Vault”.
3. 3Click “Install to Engine” and choose your Unreal Engine version.
4. 4Open your project, then Edit ▸ Plugins. Look for Locomotion Framework and tick its box.
5. 5The editor asks for a restart. Accept.

The plugin enables six others that it depends on — Enhanced Input, Editor Scripting Utilities, Animation Locomotion Library, Animation Warping, Motion Warping and Niagara. You have nothing to do, they are ticked along with it.

The plugin window

On restart, the Locomotion Framework window opens on its own: this is where character creation starts. You can reopen it at any time from the Tools ▸ Locomotion Framework menu, and the “Don’t open at startup” box in its banner stops it from coming back on launch.

This window builds the whole character in one click. Fill in five fields.

The Create Character button stays greyed out as long as a folder, a skeleton or a mesh is missing; the line under the button says which one. Once clicked, the form empties itself: that is the sign the creation succeeded.

Double-click your DataAsset. It opens on an editor made of five panels, all movable and closable like any Unreal tab.

A profile is your character in a given state: empty-handed, holding a rifle, crouched, aiming. The Profiles panel is a two-way table: one row per weapon, one column per stance.

• The + on the left adds a row, so a weapon.
• The + on top adds a column, so a stance.
• Clicking a cell opens that profile: the rest of the window starts talking about it.
• Right-clicking a cell renames, copies, pastes or deletes it.

A simple character has a single profile and you will never touch it. Weapons and aiming come much later in this documentation.

A fresh character can play nothing: it has no section. You add the ones you need, one at a time. The + button in the Sections panel opens the list of what is missing.

The menu only shows the sections that are missing, and only those that make sense for this profile — a profile without a weapon is never offered Equip, a weapon profile is never offered Lean. A section already added is gone from the list: its tab replaces it.

A new cell is not active. It shows a dash, and it will play nothing until you tell it what to do. The right-click menu decides that.

The same right-click also lets you switch off a whole column or a whole row: “Disable” takes it out of the game without erasing anything, “Delete” removes it from the grid — and its animations come back if you add it again.

Click an active cell. The Anims panel shows its contents.

The breadcrumb

The top line gives the exact address of what you are editing: the profile, the gait, the section, the state. The grid fills up quickly; this is the only thing that removes the ambiguity.

A cell holds several slots

Almost never a single animation. A start has six — three directions, two feet. A strafe cycle has eight. Idle, on the other hand, has just one. The panel lays them out like a compass: the top card is forward, the bottom ones are backward.

Three ways to fill a slot

• Drag the clip from the content browser onto the field.
• Open the dropdown and search for it by name.
• Select it in the browser, then click the arrow to the left of the field: it grabs the selected asset.

Start Position

Many slots have a Start Position field: the point in the clip, in seconds, where playback begins. It is useful when your animation opens with a wind-up you do not want to play again.

The link button

Between two foot slots sits a small link-shaped button. Closed, a single clip plays whichever foot leads. Open, each foot has its own. Click it if your animation only exists on one side.

The + to the right of the columns adds a gait: Walk, Run or Sprint. Each becomes a column, with its Loop row to fill in — the walk cycle in Walk, the run cycle in Run, the sprint cycle in Sprint.

None of them is mandatory: a character that only ever walks needs Walk and nothing else.

Movement Settings

An animation is not enough: the character also has to be told how fast it moves, otherwise the feet slide. The Movement Settings pane, below the grid, holds one column per gait.

Auto-Fill: letting the plugin measure

The Auto-Fill button reads your animations and fills Speed, Acceleration and Deceleration on its own. Here is exactly what it measures:

• Speed — the Loop clip’s displacement divided by its duration. That is the speed the animation actually carries.
• Acceleration — how long the Start clip takes to reach that speed. It isolates the ramp-up, not the clip’s total length.
• Deceleration — the same measurement, in reverse, on the Stop clip.

You can change these values during a running game (PIE) and see the effect immediately: no recompilation is needed.

Forward is the base locomotion: the character moves in the direction it is facing. It is the only section that can never be switched off; every other one grafts onto it.

The + below the last row adds a state. Seven are available, and the following pages take them one at a time.

Idle is the Idle column of the Loop row: what the character plays when it does nothing. A single slot, a single animation — the same clip whichever foot the character has just come to a halt on.

Mirror and Right Foot

Breaks

A character breathing in a loop for thirty seconds shows. Breaks are small living animations — it looks around, stretches, checks its weapon — played every now and then between two turns of the idle. The + under the slot adds as many as you want: nothing to set per clip, there is only the animation. The plugin picks one at random, never playing the same one twice in a row, and cuts it as soon as the player moves.

Without a start clip, the character jumps from standing still straight into its run cycle: it slides through the first steps. The start replaces that moment with a real set-off.

Six slots, laid out like a compass seen from above:

• Forward — L Foot and Forward — R Foot: setting off straight ahead, on the left or the right foot.
• 90° left and 90° right: setting off sideways, the quarter turn being inside the clip.
• 180° on both sides: setting off backwards, half turn included.

Which of the two Forward starts plays depends on Idle’s Mirror button. Mirror on: the standing pose really follows the stop foot, so the character sets off on the foot it had stopped on. Mirror off: the pose is the same on both sides, and the direction the player pushes decides — to the left the left-foot start, to the right the right-foot start. The 90° and 180° starts are not concerned: what they describe is a side, not a foot.

Every slot has its own Start Position. Filling in the two Forward starts is enough to feel the difference; empty directions play nothing wrong, the character simply sets off with its cycle.

Two slots only: one clip per foot, with its Start Position. The plugin picks according to the foot the character was running on when you released the input.

A stop ends on one foot — the left or the right — and it is the pose of that stop clip that gives Idle its foot. Idle has a single slot: with Mirror, it plays mirrored when the leading foot is not the clip’s one; without it, it plays as it is on both sides.

Landing in the right place

A stop must end where the character comes to rest, not two steps further on. The plugin manages this by reading the clip’s displacement: it enters the clip at the moment matching the distance still to cover.

If your clips have no root motion, tick Use Distance Curve in the Config panel and give the curve’s name in Distance Curve Name: the plugin will then read the remaining distance from that curve in your animations rather than from their movement. It is in centimetres and negative — the distance still to cover — crossing zero at the moment the character comes to rest.

The pivot is the about-turn at full speed. Without it, a character in full stride asked to head back the other way spins on itself while keeping its run cycle — and it slides.

Four cards — 90° left, 90° right, 180° left, 180° right — each with one slot per foot, its link button and its Start Position.

The 180° aligns itself

A full about-turn goes through a slow-down: the plugin uses it as an anchor. It reads the clip’s displacement, spots the plant — the instant the foot lands and the movement reverses — and enters the animation just in time for that plant to land in the right place.

If the clip has no root motion, give it a distance curve and put its name in Config ▸ Distance Curve Name. It must be in centimetres, negative before the plant, and cross zero at the moment of the plant. A curve that already reads zero at the start is ignored: it describes no approach.

With neither root motion nor a curve, the plugin falls back on Pivot Start Position 180, adjustable per gait in the Config panel: the clip then enters at a fixed instant that you tune by eye.

The 90° is tuned by hand

A quarter turn happens without slowing down: the character keeps its speed, so there is no deceleration to align on. The plugin does not try to re-time it — it enters the clip at the cell’s Start Position and plays it freely.

So that Start Position decides everything: raise it for the foot to plant earlier, lower it to leave more momentum. Tune it by eye, once per clip.

Blend Time

Under each pair of cells, Blend Time gives the length of the blend into that pivot clip. One value per card — 90° left, 90° right, 180° left, 180° right — because both feet of the same about-turn come in the same way. In strafe, every direction of the compass has its own.

Without this state, moving from walking to running swaps the two cycles with a cross-fade: the character has not accelerated, it has changed animation. A linking clip makes the change real.

The cards carry the direction of the transition — Run → Walk, Sprint → Walk. The column you are in is the destination gait: the Walk column therefore holds everything that leads into walking. Two slots per transition, depending on the foot it lands on.

Reface plays the switch between running straight ahead and moving while looking elsewhere — and back. Without it, the torso swings round in one block.

Four directions — left side, right side, back left, back right — each per foot. The bottom row tunes the trigger:

At a standstill, no movement hides a rotation: without an animation, the character turns like a statue on its base. Turn In Place plays a real turning step. This row only has a cell under Idle — it is the only place where it means anything.

Four angle steps — 45°, 90°, 135°, 180° — left and right. The plugin picks the step closest to the gap to make up.

While strafing, the character keeps its facing — towards the camera, towards a target — and moves in another direction. The section reuses the same states as Forward: Loop, Start, Stop, Pivot, Reface.

The big difference is the number of animations: a strafe cycle is not a single clip, you need one per direction. The panel lays them out as a compass.

Eight directions: forward, forward-left, forward-right, left, right, back-left, back-right, backward.

Yaw Warp: covering the angles in between

Eight directions do not cover 360°: a gap remains between two clips. Yaw warp turns the mesh slightly to fill that gap, rather than asking you for sixteen animations.

Lean tilts the character while it turns, like a cyclist in a bend. It is the only section without a grid: it does not depend on the gait, its settings apply to all four at once.

The Mode row, at the top, picks between two ways of getting that tilt: Procedural or Blend Space. They exclude each other, and one is always active — the tab opens on Procedural.

Procedural: the plugin tilts the bones

No animation to supply. The plugin computes an angle — the faster the character turns and the faster it moves, the larger it gets, capped at Max Angle — then applies it itself to the bones you list in Lean Bones, each with its axis and its share of the angle. With an empty list, it falls back on spine_01 and neck_01.

Blend Space: the tilt comes from your animations

This mode replaces the bones with a slot: Lean Blend Space expects an additive 2D blend space, added on top of the locomotion pose. The plugin samples it on its own — X is the turn (−1 left, +1 right), Y the acceleration (−1 braking, +1 accelerating) — you have nothing to wire. Max Angle and Lean Bones disappear: your blend space decides the pose.

Three moments, on three rows.

• Start — the take-off.
• Falling — the top of the jump, then the loop played on the way down.
• Land — the landing.

Any, or one column per gait

By default the jump has a single column, Any: one animation, whatever the character’s speed. The + on the right adds gait columns if you want a different take-off when walking, running and sprinting.

This is also how you restrict the jump. If you only want a character to be able to jump while running, add the columns and switch off the walk and sprint ones with a right-click: they keep their animations but no longer play.

The jump chain

The Start cell does not read “Start” but “1 jump”: a character can have several jumps chaining into each other — a jump, then a double jump, then a third. The order in the list decides which one plays.

Start Loop

The take-off has two moments in the same card: Start, the push, and Start Loop, the loop played while the character is still going up. It stops on its own at the top — there is no duration to set.

Blend Time

Under each pair of cells, Blend Time gives the length of the blend into those animations. One value per pair: both feet of the same move come in the same way.

• Start and Start Loop, in the jump card.
• Apex and Falling Loop, in the Falling window.
• The landing, in the Land window — per gait, and per direction in strafe.

Land Anticipation: entering the landing before contact

In Config, Jump Land Anticipation states at what height above the ground the landing begins, and it exists per gait. Without it the landing starts on contact: it always arrives late. With it, it starts in the air and the contact lands right.

Five movements, each on its own row.

The panel of a movement

One montage per foot, and for each of them the settings that make the hands land in the right place:

The two notifies to place on your montages

These settings assume the plugin knows two things about your montage: the frame where the hands touch the edge, and the frame where the move is over. It reads them from two notifies that you place yourself in the montage editor. Both are optional — without them the plugin guesses, less well.

The exit

You do not have to supply everything

Each movement exists per gait and per foot, but two fallbacks avoid pointless work: an empty sprint cell reuses the run one, an empty standstill cell reuses the walk one. Start with the run clips.

A weapon is not an animation, it is a profile. Add a row in the Profiles panel, name it, and a cell appears where the weapon and the stance meet.

Right-clicking that cell carries the most important decision in the system:

Equip: drawing and holstering

On a weapon profile, the section menu offers Equip — and no longer offers Lean.

• Draw — the montage played to draw.
• Sheathe — the one to holster.
• Draw VFX and Sheathe VFX — the effects that go with them.

These montages exist per gait: drawing while running is not drawing at a standstill. An empty gait cell reuses the standstill one.

Add an aim creates a sub-row under the weapon, with its own cell. It is the same weapon, in another state.

Aiming is authored in a single cell, in the Any tab. That is on purpose: aiming is a pose, not a locomotion. It layers over whatever the character is already doing — walking, running, jumping — without replacing it.

The order of the layers

1. 1The stance provides the legs and the movement.
2. 2The weapon adds its poses on top.
3. 3Aiming adds its own on top of that again.

Body Layer adds poses on top of the locomotion: breathing after a run, an injured shoulder, a clenched hand. These things have no place inside a run cycle — they must be able to arrive during any cycle, and leave again. Several layers stack.

These settings apply to the whole character, whatever the weapon or the stance. You only touch them once, when setting up.

Everything above is set in the editor, without code. This page is for the other half: what your Blueprint can ask of the character. The Locomotion LF component, sitting on the Blueprint created at the start, exposes everything that follows.

The Blueprint created for you already wires the eight actions from the Input folder. You have nothing to do for the character to respond to the gamepad — this table is here so you know where to touch if you want to change something.

Always the same pattern, and it fits in three nodes: the input action, the component, the function. Movement is the textbook example.

The blue “Locomotion Component LF” node is simply the component dragged in from the component list: that is what you plug into the Target input. You will find it in every one of these graphs.

Some actions need two outputs from the event rather than one. The jump is the typical case: press and release call two different functions.

Spawning the weapon mesh

The plugin spawns no mesh: it plays the animations and switches profile. Attaching or hiding the weapon remains your job — but it tells you at the right moment.

At the bottom of the graph, the input calls Next Weapon: it's one example of a way to switch weapons (mouse wheel, gamepad D-pad), not a requirement — build your own with the functions below. At the top, Bind On Weapon Changed subscribes to the component's On Weapon Changed event. That event directly gives the new weapon's name (New Weapon), which is passed to Attach Weapon to Socket to attach the right mesh.

Next Weapon only cycles through a list: with Allowed Profiles = [Pistol, Rifle] and Step = 1, each press moves to the next weapon. It's just one way of doing it among others — the plugin provides several functions to build your own.

Equip Weapon: equipping a specific weapon

To equip a specific weapon instead of cycling through the list — a weapon wheel, one key per weapon — use Equip Weapon. Target Profile is the weapon to equip ("Rifle", for example); leave Unarmed Profile at None so it resolves automatically from the DataAsset.

Toggle Weapon: a single draw/sheathe button

For a single button that draws if the weapon is not active and sheathes otherwise, Toggle Weapon is enough: Armed Profile is the weapon, Unarmed Profile stays at None to be resolved automatically.

Attach Weapon to Socket: the ready-made function

In the character created for you, this function does the work. One call per weapon owned is enough to show or stow all of them: Weapon says which weapon this call is for ("Rifle"), Weapon Mesh its mesh. If New Weapon matches Weapon, the mesh goes onto Socket Drawn (in hand); otherwise onto Socket Holstered (stowed on the body). Duplicate the call for each weapon, changing Weapon, Weapon Mesh and the two sockets.

The LF Profile Switch notify: timing the change to the animation

By default, the weapon changes — and On Weapon Changed fires — as soon as the draw or sheathe montage starts. To time that change to the frame where the hand closes on the weapon, place the LF Profile Switch (Weapon Draw/Sheathe) notify on the montage, at the frame you want: the change then waits for that notify instead of firing immediately. Without that notify on the montage — or without a montage at all — the change stays immediate.

Waiting for a draw to finish

Play Equip Weapon was created for people used to Play Montage who'd rather not go through the specialised functions (Equip Weapon, Toggle Weapon): it draws, sheathes or swaps weapon exactly like they do, but with the same outputs as a Play Montage — On Started, On Notify Begin, On Notify End, On Completed, On Interrupted.

A stance is a column in the profile table. You create as many as you want — crouched, injured, flying — and switch to them from the Blueprint:

Example: the Crouch stance

Setting the axis only changes the pose being played: the collision capsule belongs to Unreal, not the plugin. So the Blueprint calls two things one after the other: Set Axis State (“Posture”, your column’s name — for instance “Crouch”) for the pose, then Crouch / UnCrouch, the character’s native functions, so the capsule actually changes size.

The character created for you already wires this example on IA_Crouch: a Flip Flop alternates between the two branches on each press. The first calls Set Axis State with the name of the profile created in the Profiles tab ("Crouch", for example), then Crouch; the second calls Set Axis State with the value left at None — to return to the default stance — then UnCrouch.

The name passed to Set Axis State must exist as a column in the Profiles table (Profiles tab) — that is where you add it, with the + at the top.

Driving a Body Layer

Two nodes are available on the animation side, if you add your own layers after the plugin’s.