Slime-simulation NPM

Slime Simulation

slime

A WebGL slime simulation that creates an interactive, fluid-like background effect with physically-based rendering (PBR).

Installation

npm install slime-simulation

Basic Usage

Using with NPM/Module Bundler

import { SlimeSimulation } from 'slime-simulation';

const container = document.getElementById('container');
const sim = new SlimeSimulation(container, {
    baseResolution: 256
});

Using via CDN

<!DOCTYPE html>
<html>
<head>
    <style>
        body { margin: 0; }
        #container {
            width: 100vw;
            height: 100vh;
            position: relative;
        }
    </style>
</head>
<body>
    <div id="container"></div>
    <!-- Required dependencies -->
    <script src="https://unpkg.com/three@0.158/build/three.min.js"></script>
    <script src="https://cdn.jsdelivr.net/npm/lil-gui@0.19"></script>
    <!-- Slime Simulation -->
    <script src="dist/slime-simulation.js"></script>
    <script>
        const container = document.getElementById('container');
        const sim = new SlimeSimulationLib.SlimeSimulation(container, {
            baseResolution: 256,
            showGui: true
        });
    </script>
</body>
</html>

Configuration

Constructor Options

Option	Default	Description
baseResolution	128	Base resolution (higher = better quality but slower)
stretchFactor	1.0	Adjust resolution aspect ratio
showGui	false	Show/hide control panel
imagePath	null	Optional background image path (will load asynchronously)
preset	'default'	Name of preset to use
params	{}	Override any simulation parameters (see Parameters section)

Available Presets

default: Standard liquid metal effect with purple base
purple: High contrast purple with red accents
emerald: Green, crystalline effect
glass: Transparent glass-like effect (works best with background image)

Simulation Parameters

All parameters can be updated using updateSettings():

sim.updateSettings({
    // Simulation
    uNoiseFactor: 0.005,     // 0.0-0.1
    uBirthRate: 0.9,         // 0.0-1.0
    uDeathRate: 0.6,         // 0.0-1.0
    uSustainRate: 0.985,     // 0.0-1.0
    uSpeed: 0.1,             // 0.0-1.0
    uSampleRadius: 4.0,      // 0-15
    uGrowthTarget: 10.0,     // 0.0-100.0
    uMouseMass: 0.6,         // 0.2-1.0
    uMouseRadius: 0.05,      // 0.01-0.2
    uGaussianWeight: 8.0,    // 4-20

    // Visual
    uBaseColor: new THREE.Vector3(0.1, 0.01, 0.8),
    uSecondaryColor: new THREE.Vector4(0.0, 0.0, 0.0, 0.0),
    uSpecularColor: new THREE.Vector3(0.725, 0.725, 0.725),
    uRoughness: 0.2,         // 0.05-0.95
    uMetalness: 0.0,         // 0-1
    uToneMappingDenominator: 2.2,  // 1.8-2.4
    uLightPosZ: 2.0,         // 1-3
    uHeightMultiplier: 1.0,  // 0.5-3
    uNormalMultiplier: 2.0,  // 1-8
    uNormalZComponent: 1.0,  // 0.2-1.5

    // Effects
    uGlassEffect: false,
    uShowImage: true,
    uSmoothNormals: true,
    uSpotlightDampening: true
});

API

Methods

updateSettings(settings)

Update simulation parameters:

sim.updateSettings({
    // Simulation parameters
    uNoiseFactor: 0.005,    // Amount of noise/randomness
    uBirthRate: 0.9,        // Rate at which new cells appear
    uDeathRate: 0.6,        // Rate at which cells die
    uSustainRate: 0.985,    // How long cells persist
    uSpeed: 0.1,            // Overall simulation speed
    uMouseMass: 0.6,        // Strength of mouse interaction
    uMouseRadius: 0.05,     // Size of mouse influence
    
    // Visual parameters
    uBaseColor: new THREE.Vector3(0.1, 0.01, 0.8),  // Primary color (RGB)
    uSecondaryColor: new THREE.Vector4(0.0, 0.0, 0.0, 0.0),  // Secondary color (RGBA)
    uRoughness: 0.2,        // Material roughness
    uMetalness: 0.0,        // Material metalness
    uGlassEffect: false     // Enable glass-like effect
});

applyPreset(presetName)

Apply a predefined set of parameters:

sim.applyPreset('purple');  // Available presets: 'default', 'purple'

destroy()

Clean up and remove the simulation:

sim.destroy();

Advanced Usage

Async Initialization

Sometimes you may need to wait for the simulation to fully initialize before updating settings:

async function init() {
    const container = document.getElementById('container');
    const sim = new SlimeSimulationLib.SlimeSimulation(container, {
        baseResolution: 256
    });

    // Wait for simulation to initialize
    await new Promise(resolve => {
        const checkInit = () => {
            if (sim.simulationMaterial && sim.renderMaterial) {
                resolve();
            } else {
                setTimeout(checkInit, 100);
            }
        };
        checkInit();
    });

    // Now safe to update settings or apply presets
    sim.updateSettings({
        uBaseColor: new THREE.Vector3(0.1, 0.01, 0.8),
        uRoughness: 0.2
    });
}

Using with Background Image

The simulation can distort a background image with a glass-like effect:

const sim = new SlimeSimulation(container, {
    baseResolution: 256,
    preset: 'glass',  // Glass preset is optimized for image distortion
    imagePath: 'https://picsum.photos/1024/768',  // Your background image
    params: {
        uGlassEffect: true,     // Enable glass effect
        uShowImage: true,       // Show the background image
        uMetalness: 0.1,        // Lower metalness for more transparency
        uRoughness: 0.05        // Lower roughness for clearer refraction
    }
});

// Note: The image should be:
// - CORS-enabled (accessible from your domain)
// - Ideally power-of-two dimensions (e.g., 1024x1024)
// - Not too large (1024x1024 is usually sufficient)

Controls

Simulation Parameters

Parameter	Range	Description
Resolution	4-1024	Controls the simulation resolution. Higher values increase detail but impact performance
Noise Factor	0.0-1.0	Amount of random noise added to the simulation
Birth Rate	0.0-1.0	Threshold for new cells to appear (similar to Conway's Game of Life)
Death Rate	0.0-1.0	Threshold for cells to disappear
Sustain Rate	0.0-1.0	How well existing cells maintain their state
Speed	0.0-1.0	Overall simulation speed
Sample Radius	0-15	How far each cell looks for neighbors
Growth Target	0.0-100.0	Maximum value for cell growth
Mouse Mass	0.2-1.0	Strength of mouse/touch interaction
Mouse Radius	0.01-0.2	Size of mouse/touch influence area
Gaussian Weight	4-20	Smoothness of neighbor sampling

Render Parameters

Parameter	Range	Description
Roughness	0.05-0.95	Surface roughness for PBR rendering
Metalness	0-1	Metallic quality of the surface
Tone Mapping	1.8-2.4	Overall brightness/contrast adjustment
Light Height	1-3	Height of the moving light source
Height Multiplier	0.5-3	Intensity of height displacement
Normal Multiplier	1-8	Strength of surface normal effects
Normal Z Strength	0.2-1.5	Vertical component of surface normals

Technical Details

The simulation uses a ping-pong buffer technique with two render targets to update the state. The state consists of:

Red channel: Mass/density
Green channel: Velocity
Blue channel: Height
Alpha channel: Fixed at 1.0

The rendering pipeline implements PBR (Physically Based Rendering) with custom normal calculation and various material properties that can be adjusted in real-time.

Browser Support

Requires WebGL 2.0 support. Works in all modern browsers including mobile browsers (with reduced resolution).

Dependencies

Three.js (^0.158.0)
lil-gui (^0.19.0)

Performance Tips

Lower baseResolution for better performance on mobile devices
Adjust stretchFactor to balance quality and performance
Disable GUI in production for better performance

// Example with full configuration
const sim = new SlimeSimulation(container, {
    baseResolution: 256,
    showGui: true,
    preset: 'blue',
    params: {
        // Override any preset parameters
        uBaseColor: new THREE.Vector3(0.0, 0.3, 0.8),
        uMetalness: 0.5
    }
});

// Or use preset only
const sim = new SlimeSimulation(container, {
    preset: 'glass'
});

// Or configure everything manually
const sim = new SlimeSimulation(container, {
    params: {
        uNoiseFactor: 0.005,
        uBirthRate: 0.9,
        // ... all other parameters
    }
});

Note: When using imagePath, the simulation will initialize asynchronously after the image loads. All other options (including presets and params) will be applied automatically after initialization.

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