Constraint
Base class for creating particle constraints and forces
Constructor
new Constraint(name: string, glsl?: string, uniforms?: Record<string, any>)Parameters
| Parameter | Type | Description | Default |
|---|---|---|---|
| name | string | Unique name for the constraint | - |
| glsl | string | GLSL shader code for the constraint | "" |
| uniforms | Record<string, any> | Uniform values for the shader | {} |
Properties
| Property | Type | Description |
|---|---|---|
| name | string | Unique identifier for the constraint |
| active | boolean | Whether the constraint is active |
| glsl | string | GLSL shader code that implements the constraint |
| uniforms | Record<string, any> | Uniform values passed to the shader |
| params | Record<string, { value: number | number[], hardcode?: boolean }> | null | Parameter definitions for the constraint |
Methods
build(): void
Processes the constraint's parameters and builds the final GLSL code.
Example Usage
import { Constraint, PropertyManager } from 'particlize';
// Create a basic gravity constraint
const gravity = new Constraint(
'gravity',
`
vec3 gravity = vec3(0.0, -0.1, 0.0);
velocity.xyz += gravity * u_deltaTime;
`,
{
u_deltaTime: 0.016
}
);
// Create property manager and add constraint
const propertyManager = new PropertyManager({ /* ... */ });
propertyManager.addProperty('velocity', { size: 3 });
propertyManager.addConstraint('velocity', gravity);
// Create a custom parameterized constraint
class SinewaveConstraint extends Constraint {
constructor(amplitude: number, frequency: number) {
super('sinewave');
this.params = {
amplitude: { value: amplitude, hardcode: true },
frequency: { value: frequency, hardcode: false }
};
this.glsl = `
float amplitude@ = #AMPLITUDE;
float frequency@ = #FREQUENCY;
position.y += sin(position.x * frequency@ + u_time) * amplitude@;
`;
}
}
// Use custom constraint
const sinewave = new SinewaveConstraint(0.5, 2.0);
propertyManager.addConstraint('position', sinewave);Constraints
In particlize, constraints are used to define conditions that are imposed on particles, such as their positions, velocities, or other properties. These constraints can be used to create complex behaviors and interactions between particles.
DirectionalForce
Constraint that applies constant force in a specific direction