ParticleSystemExtensions.cs

//
// ParticleSystem extensions for changes introduced in Unity 5.3
// by Nothke, unlicensed
//
// Each module in ParticleSystem in Unity 5.3 is now a struct,
// which makes setting some simple stuff more cumbersome
// These extensions provide shortcuts to simplify those tasks
//
// For example: setting constant emission rate now takes 3 lines at minimum,
// rather than a single line like before.
//

using UnityEngine;
using System.Collections;

public static class ParticleSystemExtensions
{
    // Emission

    /// <summary>
    /// Sets constant emission rate. Replaces particleSystem.emissionRate
    /// </summary>
    /// <param name="rate">Constant emission rate</param>
    public static void SetEmissionRate(this ParticleSystem particleSystem, float rate)
    {
        ParticleSystem.EmissionModule em = particleSystem.emission;
        ParticleSystem.MinMaxCurve rCurve = new ParticleSystem.MinMaxCurve(rate);
        em.rate = rCurve;
    }

    /// <summary>
    /// Sets emission rate between two random values
    /// </summary>
    /// <param name="rateRandomMin">Minimum random value</param>
    /// <param name="rateRandomMax">Maximum random value</param>
    public static void SetEmissionRate(this ParticleSystem particleSystem, float rateRandomMin, float rateRandomMax)
    {
        ParticleSystem.EmissionModule em = particleSystem.emission;
        ParticleSystem.MinMaxCurve rCurve = new ParticleSystem.MinMaxCurve(rateRandomMin, rateRandomMax);
        em.rate = rCurve;
    }

    /// <summary>
    /// Sets emission rate to a curve
    /// </summary>
    /// <param name="curve">Curve</param>
    /// <param name="scale">Scalar for the curve</param>
    public static void SetEmissionRate(this ParticleSystem particleSystem, AnimationCurve curve, float scale = 1)
    {
        ParticleSystem.EmissionModule em = particleSystem.emission;
        ParticleSystem.MinMaxCurve rCurve = new ParticleSystem.MinMaxCurve(scale, curve);
        em.rate = rCurve;
    }

    /// <summary>
    /// Enables or disables emission. Replaces particleSystem.enableEmission
    /// </summary>
    /// <param name="particleSystem"></param>
    /// <param name="enable"></param>
    public static void EnableEmission(this ParticleSystem particleSystem, bool enable)
    {
        ParticleSystem.EmissionModule em = particleSystem.emission;
        em.enabled = enable;
    }

    // Shape

    /// <summary>
    /// Sets particle casting shape angle. Only works if the shape is a cone
    /// </summary>
    public static void SetShapeAngle(this ParticleSystem particleSystem, float angle)
    {
        ParticleSystem.ShapeModule shape = particleSystem.shape;
        shape.angle = angle;
    }

    /// <summary>
    /// Sets particle casting shape's radius. Only works if the shape is a sphere, hemisphere or a circle
    /// </summary>
    public static void SetShapeRadius(this ParticleSystem particleSystem, float radius)
    {
        ParticleSystem.ShapeModule shape = particleSystem.shape;
        shape.radius = radius;
    }

    /// <summary>
    /// Sets particle casting shape's box extents. Only works if the shape is a box
    /// </summary>
    public static void SetShapeBoxSize(this ParticleSystem particleSystem, Vector3 boxSize)
    {
        ParticleSystem.ShapeModule shape = particleSystem.shape;
        shape.box = boxSize;
    }
}