Interactive 2D Projectile Motion Simulator
Explore kinematic equations with our real-time 2D Projectile Motion lab. Simulate trajectories, calculate max height, and analyze range with precision.
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1. The Core Engine
The logic is driven by the Three.js framework, but the "brain" is a custom Integration Engine that handles real-time physical states.
- Time-Step Integration: The engine uses a high-precision clock (
performance.now()) to calculate positions. This ensures the simulation remains physically accurate regardless of frame rate fluctuations. - Pause Logic: It features a sophisticated state handler for pausing. It calculates
totalPausedTimeto ensure the kinematic equations resume exactly where they left off without "teleporting" the projectile. - Integrity System: A background "Security Guard" runs every 3 seconds, monitoring the DOM for the presence of developer attribution. If the footer is removed, the engine triggers a
location.reload()to protect intellectual property.
2. Rendering Technology
The visuals utilize a Post-Processing WebGL Stack to achieve a "Computer Terminal" aesthetic.
- Effect Composer: Rather than rendering directly to the screen, the engine renders into a buffer.
- Unreal Bloom Pass: This specific pass creates the glowing "neon" effect. It identifies high-intensity colors (like the projectile's emissive orange) and bleeds them into adjacent pixels.
- Orthographic Camera: The lab uses an
OrthographicCamera. Unlike a perspective camera, it eliminates depth distortion, which is critical for scientific measurement. This ensures that a distance of 50m looks identical at the front or back of the scene. - Dynamic Canvas Textures: The
liveHUDand labels are rendered using a "Canvas-within-a-Texture" approach. JavaScript draws text onto an off-screen HTML5 canvas, which is then mapped onto 3D Sprites in real-time.
3. Mathematical Tools
The simulation is a direct implementation of Classical Kinematics and Vector Analysis.
- Parabolic Equations: The $x$ and $y$ coordinates are calculated every frame using:

- Vector Calculus: The engine calculates the Instantaneous Velocity Vector by finding the square root of the sum of squared components:

- Geometric Projections: The code uses Spline-like trail mapping. As the projectile moves, its previous coordinates are pushed into an array (
trailPoints) and converted into aBufferGeometryto render the path.
4. Front-End Environment
The environment is a Hybrid UI/3D Workspace built on modern web standards.
- Import Maps: The project uses native browser
importmapto resolve dependencies likethreeandlil-guidirectly from CDNs without needing a build tool like Webpack or Vite. - lil-gui Integration: It includes a floating "control deck" that allows users to manipulate parameters (velocity, angle, gravity) in real-time.
- Responsive CSS Overlays: The
overlaydiv usespointer-events: none, which allows users to read the data while still interacting with the 3D scene (panning and orbiting) underneath the text. - Typeface Rendering: The environment uses the
Courier Newmonospace font to reinforce the technical, laboratory theme of the application.