S.O.A.P

2025.08 - Now

A third-person action game where players clean floors, defeat enemies and earn points in an arena.

Project
Academic team project
Engine
Unreal Engine
View gameplay flow

Demo

Team trailer · April 2026

Open demo ↗Play on itch.io ↗

Gameplay flow

Gameplay sequence

  1. Move

    Slide and drift through the arena.

  2. Clean

    Clean the floor to increase coverage.

  3. Contest

    Fight enemies and reclaim re-dirtied areas.

Return to move

My contribution

Interactive Ground
Built all functionality related to cleaning the floor and changing its surface state.
UI implementation
Implemented every UI feature: the in-game HUD, title screen, settings and other interface screens.
Scoring system
Developed the complete score calculation system.
Music & audio
Composed the BGM, sourced sound effects and implemented the entire audio system.
S.O.A.P gameplay showing a cleaned trail, score and in-game HUD
Cleaning the ground updates the score and HUD.

Inspiration

The team combined cleaning with score-based arena combat. Enemies can re-dirty the floor, so clearing an area once does not secure it for the rest of the round.

Gameplay

Soap Shoes preserve momentum. Players slide, drift and use slopes to turn or reposition instead of stopping immediately.

Cleaning increases floor coverage; defeating enemies adds points. Re-dirt trails force players to decide whether to clear an area again or keep moving.

Bath Bomb cleans an area in a burst. Bubble Wand applies coverage at range, letting players clean ahead while moving.

Cleaning trails and enemies in the arena
Cleaning trails and enemies in the arena
S.O.A.P — Gameplay
S.O.A.P — Gameplay

Technical Implementation

Interactive Ground

I built the Interactive Ground system. Its drawing pipeline connects three different spaces: a collision in the world, a position in the surface’s UVs, and pixels in a Render Target.

Ground cleaning in play

The player leaves a visible cleaning trail while moving. The score changes in the HUD as the ground is cleaned, showing the surface system and UI together.

5.5 seconds
Interactive Ground · world to texture

  1. Resolve the contact

    Trace the surface and validate its collision UV.

  2. Convert the scale

    Translate world-sized brushes into texture pixels.

  3. Update the surface

    Select the clean / dirty material and draw to the Render Target.

Collision and UV mapping

BP_Canvas → Splash traces vertically around the supplied world position, ignoring the player. It extracts collision UVs from the hit and identifies the target Canvas.

Both the hit and UV lookup must succeed before Paint is called. This keeps a failed surface lookup from becoming a paint operation at an unintended texture position.

Splash Blueprint: world-position trace, hit and UV success branches, Canvas cast and Paint call.
Find the surface contact point and map it to texture coordinates.

Brush size conversion

A fixed pixel-sized brush would cover different world distances on differently scaled surfaces. UpdateCanvasMetrics derives canvas width and height from the mesh’s local bounds × world scale.

Paint uses those dimensions to calculate the brush footprint on each texture axis, then subtracts half the footprint to centre the mark on the UV-derived position.

World brush size ÷ canvas world sizeRender Target resolutionBrush size in pixels

Calculated separately for X and Y.
UpdateCanvasMetrics Blueprint: local mesh bounds and world scale calculate Canvas World Width and Height.
Calculate the canvas’s world-space dimensions.

Cleaning and dirt rendering

Cleaning and re-dirtying share the same positioning and sizing calculations. In BP_Canvas → Paint, the Dirty flag selects the brush material for that operation.

Begin Draw → Draw Material → End Draw writes that change into the Render Target.

BP_Canvas Paint Blueprint: brush selection, canvas-size calculations and the connected render-target drawing sequence.
Apply a cleaning or dirt brush to the surface.
UI, scoring and audio

I implemented Interactive Ground, score calculation and every UI feature, including the HUD, title screen and settings. Surface changes feed the coverage and score feedback shown during play.

The project uses Unreal Blueprints and UMG. I also composed the BGM, sourced sound effects and implemented the audio system.

Related AI project

Boss decision system

For a separate AI course, I built a Boss action-selection algorithm on top of SOAP. It scores combat conditions and selects between behaviors supplied by teammates.

View Boss AI case study and demo ↗

S.O.A.P

Back to overview ↑