StepSense
Surface-aware footsteps, landings and footprints

Overview

StepSense is a complete footstep system for Unreal Engine. It works with any Character, any Pawn and even plain actors, on any skeleton, with or without footstep notifies.

• StepSense Footstep notify: place it where a foot touches the ground; it traces down from the foot bone.
• StepSense Profile data assets: per surface type or physical material - sounds, volume and pitch ranges, footprint decal, particle and a VFX tag.
• Automatic stepping: no notifies needed - a speed-based stride with alternating feet.
• Jumps and landings scaled by the fall velocity.
• Loudness from speed and stance (walk, run, crouch, sneak).
• Surface override volumes for puddles, snow, carpets and shallow water.
• Footprint decals with lifetime, fade and a world-wide pool that removes the oldest first.
• Left/right feet with mirrored right-foot decals and per-foot offsets.
• AI hearing: every step is a noise event for AI Perception or Pawn Sensing.
• Per-character profiles layered over the project's default profile.
• Throttle: minimum interval per foot, sound limits per character and per world.
• Wet and dirt trails after leaving a surface.
• Events for Blueprint and C++, a Blueprint library and the StepSense.Debug console variable.

Requirements

Installation

1. Install StepSense from Fab into your engine, or copy the StepSense folder into your project's Plugins folder.
2. Enable StepSense in Edit > Plugins and restart the editor.
3. C++ only: add PublicDependencyModuleNames.Add("StepSense"); to your Build.cs.

Quick start

1. In Project Settings > Physics > Physical Surface name a few surface types (Grass, Wood, Metal, Snow). Create physical materials with those surface types and assign them to your floor materials, meshes or landscape layers.
2. Create a profile: Add > Miscellaneous > Data Asset > StepSense Profile. Add one entry per surface with a Footstep Sound and optionally a Decal, and one entry with Surface = Default as the fallback.
3. In Project Settings > Plugins > StepSense set Default Profile to it.
4. Add the StepSense component to your character Blueprint.
5. Open the walk and run animations, right-click a notify track, Add Notify > StepSense Footstep on every frame a foot lands, and set Foot to Left or Right. No time for notifies? Set the component's Step Mode to Automatic instead.
6. Play and type StepSense.Debug 1 in the console to see traces, surfaces and loudness.

1. Footstep notify

Anim Notify UStepSenseNotify — displayed as StepSense Footstep. Its title on the track is Step L / Step R (plus the bone when set).

When the owner has a StepSense component, the notify hands the step to it: throttle, loudness, trails, AI noise and events all apply. Without a component it traces from the bone and plays the step directly through Play Step At Location.

2. Surface profiles

Data Asset UStepSenseProfile — Add > Miscellaneous > Data Asset > StepSense Profile. Properties: Surfaces (array of entries) and Parent Profile (see Profile layering).

An entry is matched by its Physical Material first (when set), then by Surface, then the entry whose Surface is Default is used as the fallback.

struct FStepSenseSurfaceEntry

3. Automatic stepping

Set Step Mode on the component:

Stride = Base Stride (40) + speed × Stride Speed Factor (0.12), clamped to Min Stride (40) - Max Stride (140) cm, times Crouch Stride Scale (0.75) while crouched. At 300 cm/s that is 76 cm, at 600 cm/s 112 cm. Below Min Auto Step Speed (20 cm/s) or in the air no step is generated; the first step after starting to move comes after half a stride. With Use Foot Bones In Automatic Mode (on) the trace starts at the foot bones when the mesh has them, otherwise at the bottom of the actor, Foot Spacing (12 cm) to each side.

Automatic stepping works for any actor whose velocity moves it, also on simulated proxies and dedicated servers (where the animation may not tick). Get Stride Length returns the current stride.

4. Jumps & landings

On a Character the component binds Landed and Movement Mode Changed automatically:

• Landing: the highest downward speed of the fall is measured. Below Min Landing Speed (250 cm/s) nothing happens. Intensity = (speed - Min) / (Max Landing Speed (1200) - Min), clamped 0-1. Loudness is multiplied by Lerp(1, Max Landing Loudness (2.5), Intensity), so hard landings are louder and carry further for AI. The surface's Land Sound and particle play at the ground, and with Landing Footprints (on) both feet leave a print.
• Jump: leaving the ground (Walking to Falling) with an upward speed of at least Min Jump Speed (100 cm/s) plays the surface's Jump Sound with loudness × Jump Loudness (0.8).

Simulated proxies in multiplayer do not always receive Landed; StepSense then uses the movement mode change (Falling to Walking) instead, never both. Turn the features off with Landing Effects / Jump Effects. For pawns that are not Characters call Trigger Landing (impact speed) and Trigger Jump yourself; Trigger Landing ignores the Landing Effects switch but respects Min Landing Speed.

5. Speed- and stance-based loudness

Every step gets a loudness value used for the volume, the AI noise and the events:

Loudness = Stance multiplier x Speed factor x Surface Loudness Multiplier x Notify Loudness Multiplier x Loudness Scale

Speed factor = Lerp(Min Speed Loudness (0.5), 1, speed / Loudness Reference Speed (600)), or the value of Speed Loudness Curve (speed → factor) when set. With Loudness Affects Volume (on), the sound volume is the random volume × loudness clamped to Max Volume Scale (1.5) × Volume Scale (1). Get Stance, Get Speed and Get Current Loudness expose the values.

6. Surface override volumes

Volume AStepSenseSurfaceVolume — Place Actors > Volumes > StepSense Surface Volume. Steps whose ground point lies inside it use the volume's surface instead of the detected one: puddles on asphalt, snow drifts, carpets, shallow water.

Make the volume reach a little above and below the ground. Volumes register when play begins. Contains Location and Get Override Surface are available in Blueprint; Find Surface Volume returns the volume at a location.

7. Footprint decals & pool

Each step spawns the surface's Decal at the ground point, projected along the ground normal and pointing in the actor's facing direction (rotate it with Footprint Yaw Offset to match your texture). After Decal Lifetime seconds the print fades over Decal Fade Duration and is destroyed.

Every print enters a per-world pool limited to Max Footprints (64, project settings). When the pool is full, the oldest print is removed. Change the limit at runtime with Set Max Footprints on the StepSense subsystem; 0 disables footprints.

Turn prints off per character with Spawn Footprints, or per notify with Spawn Footprint. No decals are spawned on dedicated servers.

8. Left/right feet, mirroring and offsets

• Notifies carry their Foot; automatic stepping alternates Left, Right, Left... and continues from the last notified foot in Hybrid mode.
• Left Foot Bone / Right Foot Bone (foot_l / foot_r) are the bones or sockets traced from.
• Left Foot Offset / Right Foot Offset (0, 0, 0) shift each foot's trace and print in actor space (X forward, Y right, Z up).
• Mirror Right Footprint (on): right-foot prints use the left decal mirrored across the walking direction, unless the surface entry has a Right Foot Decal.
• Each foot has its own Min Step Interval timer (see Throttle).

9. AI hearing

Every footstep, jump and landing can be reported as a noise:

Noise loudness = step loudness × Noise Loudness Scale (1). Range = Noise Max Range (1500 cm), multiplied by the loudness when Scale Noise Range By Loudness is on; 0 lets the listener's hearing range decide. The noise carries Noise Tag (Footstep) and the owner as instigator. With Noise Only On Authority (on) noise is reported only on the server or in standalone, where AI runs. A sneaking character on snow is therefore far quieter than a running one on metal.

10. Per-character profile layering

Surfaces are looked up in this order, the first match wins:

1. the Custom Entry of a surface volume (when enabled);
2. the component's Profile, then its Parent Profile chain;
3. the Default Profile of the project settings, then its parents.

Within that chain a physical-material entry wins over a surface-type entry, and the Default surface entry is the last fallback. A heavy robot therefore only needs a profile with its own Metal and Concrete entries; every other surface still comes from the project's default profile. Switch at runtime with Set Profile (armour on, barefoot...). Find Surface Entry shows which entry a character would use.

11. Throttle & concurrency

Each entry can also set a Sound Concurrency asset for engine-level voice limiting.

12. Wet & dirt trails

Give an entry Trail Footprints > 0 (for example Mud = 6). After the character leaves that surface, the next N footprints on other surfaces use the mud entry's Trail Decal (or its Decal when empty) instead of the new surface's print. Stepping back onto mud ends the trail; leaving another trail surface starts a new one.

When Trail Strength Parameter is set (for example TrailStrength), each trail print gets a dynamic material with that scalar going from 1 on the first print down towards 0 on the last, so the trail can fade out step by step. The step info's Trail Footprint flag marks trail prints. Get Remaining Trail Footprints and Clear Trail (for example after walking through water) are on the component.

13. Events

struct FStepSenseStepInfo (Step): Event Type (Footstep / Jump / Landing), Foot, Surface, Surface Name, Physical Material, Location, Normal, Loudness, Speed (impact speed for landings), Stance, From Notify, Trail Footprint, VFX Tag, Volume, and the spawned Audio, Footprint and Particle components (null when none). Get Last Step returns the latest one.

14. Blueprint library

Function Library UStepSenseLibrary — category StepSense.

Profiles also offer Find Entry (Surface, Physical Material, Include Parents).

15. Debugging

Console variable StepSense.Debug (development and debug builds; nothing is drawn in shipping builds):

Component reference

Component UStepSenseComponent — displayed as StepSense. Add it to any actor; on a Character it uses the Character mesh, otherwise the first skeletal mesh of the owner (Set Foot Mesh to change).

Settings & subsystem

Developer Settings UStepSenseSettings — Project Settings > Plugins > StepSense (saved in DefaultGame.ini): Default Profile (None), Max Footprints (64), Max Step Sounds (24).

World Subsystem UStepSenseSubsystem — one per world (game, PIE, editor and editor preview worlds): Find Volume At, Get Footprint Count, Clear Footprints, Set / Get Max Footprints, Get Active Step Sound Count, Set / Get Max Step Sounds (negative = back to the project setting).

C++

#include "StepSenseComponent.h"
#include "StepSenseLibrary.h"

// React to every step
Steps->OnFootstep.AddDynamic(this, &AMyCharacter::HandleFootstep);

void AMyCharacter::HandleFootstep(EStepSenseFoot Foot, TEnumAsByte<EPhysicalSurface> Surface,
    FVector Location, FVector Normal, float Loudness, const FStepSenseStepInfo& Step)
{
    if (Step.VFXTag == TEXT("Splash")) { /* spawn your Niagara system at Location */ }
}

// Stealth
Steps->SetSneaking(true);

// One-off step anywhere
FStepSenseStepInfo Step;
UStepSenseLibrary::PlayStepAtLocation(this, GetActorLocation(), nullptr, Step, EStepSenseFoot::Left, GetActorRotation().Yaw);

C++ helpers on the library: ResolveEntry, SpawnStepEffects (with FStepSenseSpawnRequest), MakeFootprintRotation, FillSurfaceHit, ApplySurfaceVolume; on profiles: GetProfileChain, FindInChain.

Troubleshooting

Credits

© 2026 Alpha XP — alphaxp.net · Support: support@alphaxp.net. Built for Unreal Engine 4.27 and 5.8.