An interactive real-time 3D liquid simulation controlled using hand gestures through your webcam.
This project combines computer vision, physics simulation, and real-time rendering to create a cube filled with dynamic liquid particles that react to your hand movements.
The cube rotates, tilts, and resizes based on detected gestures while the liquid inside behaves according to simulated physics such as gravity, particle interaction, and collision with cube walls.
You can record a GIF using tools like OBS Studio, ScreenToGif, or ShareX.
• Real-time hand gesture recognition • Interactive 3D cube rotation • Particle-based liquid simulation • Smooth fluid rendering using Gaussian blur • Depth-based color gradients for realistic liquid appearance • Gesture-controlled cube resizing • Dynamic rotation inertia and flick interaction • Runs entirely on CPU with webcam
| Gesture / Key | Action |
|---|---|
| Open Hand | Rotate cube |
| Fast Hand Movement | Increase spin speed |
| Closed Fist | Freeze cube rotation |
| Pinch (Thumb + Index) | Resize cube |
| Q key | Quit the simulation |
Press Q on your keyboard while the simulation window is active.
The program will safely close:
cap.release()
cv2.destroyAllWindows()
You can also stop the program from the terminal with:
Ctrl + C
• Python • OpenCV – camera input and rendering • MediaPipe – real-time hand tracking • NumPy – numerical computations • Particle-based physics simulation
https://github.com/Subham503/3D-Liquid-Cube-Simulation.git
cd 3D-LiquidSimulation
python -m venv venv
Activate it:
Windows
venv\Scripts\activate
Mac / Linux
source venv/bin/activate
pip install mediapipe opencv-python numpy
Download the MediaPipe hand tracking model:
hand_landmarker.task
Download link:
https://storage.googleapis.com/mediapipe-models/hand_landmarker/hand_landmarker/float16/1/hand_landmarker.task
Place it in the project folder:
3-D-Liquid-simulation/
3D-LiquidSimulation
│
├── 3-D-Liquid-simulation
│ ├── 3-D liquid simulation.py
│ ├── hand_landmarker.task
│ ├── README.md
│ └── LICENSE
│
└── venv
Navigate into the simulation folder:
cd 3-D-Liquid-simulation
Run the program:
python "3-D liquid simulation.py"
A window titled Blue Liquid Cube will appear and your webcam will start tracking your hand.
The program uses MediaPipe to detect 21 hand landmarks in real time.
These landmarks include:
• Wrist • Finger joints • Fingertips
These points allow the system to determine hand gestures and motion direction.
The fingertip centroid is used to calculate movement velocity.
Rotation sensitivity dynamically scales with motion speed:
• slow movement → slow cube rotation • fast flick → rapid spinning cube
The cube contains 350 simulated particles.
Each particle follows physics rules including:
• gravity • particle repulsion • wall collisions • velocity damping
This creates the effect of sloshing liquid inside the cube.
Particles are rendered as soft Gaussian blobs.
Overlapping blobs blend together to create a smooth fluid surface effect.
Colors vary based on:
• depth • velocity • lighting approximation
• Python 3.9+ • Webcam • Windows / Mac / Linux
No GPU required.
• Glass cube rendering • Surface tension simulation • GPU acceleration for thousands of particles • WebGL browser version • AR interaction
This project is licensed under the MIT License.
See the LICENSE file for details.
Subham
Undergraduate student exploring Machine Learning, Computer Vision, and Interactive Simulations.
• MediaPipe team for the hand tracking model • OpenCV community • Real-time particle physics simulation techniques used in graphics engines