PhysXTest - Unreal Engine 4 Physics Demos

A collection of physics simulation demos built with Unreal Engine 4.27 and PhysX to showcase various physics scenarios and stress-test the engine's physics capabilities.

Purpose

This project serves as a testbed for exploring PhysX physics simulations in Unreal Engine 4. Each demo focuses on different aspects of physics simulation.

Target Engine: Unreal Engine 4.27 with PhysX physics backend. Can also be used for comparison with Chaos physics (UE5).

Implementation Note: All object spawning is done in C++ to avoid Blueprint VM overhead and ensure accurate physics performance benchmarking.

• Rigid body dynamics - Mass, velocity, collisions
• Large-scale simulations - Hundreds to thousands of physics objects
• Broadphase performance - Many simultaneous collisions
• Stacking stability - Object piling and structural integrity

Demos

Wrecking Ball

A massive ball impacts a brick wall, testing impulse transfer and large-scale destruction physics.

Features:

• Configurable wall dimensions (rows/columns)
• Adjustable brick mass and size
• Ball mass, radius, and launch velocity settings
• Wall collapse mode (gravity only) or ball impact mode

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Domino Effect

Classic domino chain reaction demonstrating sequential collision propagation.

Features:

• Curved domino arrangements
• Precise collision timing
• Chain reaction physics

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Fluid Particles

Simulates fluid-like behavior using hundreds of small physics spheres in a container.

Features:

• 500+ particle spheres
• Container with physics walls
• Stirring force simulation
• Broadphase stress testing

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Tower Stacking

Physics cubes spawned from above, forming unstable tower structures that eventually collapse.

Features:

• Gradual cube spawning (configurable rate)
• Random or fixed cube sizes
• Auto-restart after simulation time
• Up to 1000+ physics objects

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Technical Details

GameModes

Each demo has its own GameMode class with exposed properties for easy configuration:

GameMode	Description
APhysXDemoGameMode	Basic cube spawning demo
APhysXWreckingBallGameMode	Wall destruction with ball impact
APhysXDominoGameMode	Domino chain effect
APhysXStackingTowerGameMode	Tower building simulation
APhysXFluidParticlesGameMode	Particle container simulation
APhysXExplosionGameMode	Explosion physics
APhysXConveyorGameMode	Conveyor belt simulation

Configuration

All demos support:

• Auto-restart - Automatically resets after configurable time
• Debug stats - On-screen physics statistics
• Material customization - Custom materials for objects
• Blueprint exposure - All properties editable in Blueprint

Requirements

• Unreal Engine 4.27
• PhysXVehicles plugin (enabled)
• Windows 64-bit

Setup

1. Clone the repository
2. Right-click PhysXTest.uproject and select "Generate Visual Studio project files"
3. Open in Unreal Editor or build from Visual Studio
4. Open any L_* level (e.g., L_WreckingBall, L_Domino)
5. Press Play to start the simulation

Levels

Level	Demo
L_CubeFalls	Basic cube spawning
L_WreckingBall	Wrecking ball demo
L_Domino	Domino effect
L_TowerStacking	Tower stacking
L_FluidParticle	Fluid particles

License

This project is for educational and testing purposes.