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lassemt/fadeInParticlesSparkAR.js

Created November 24, 2020 19:53
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  1. lassemt renamed this gist Nov 24, 2020. 1 changed file with 0 additions and 0 deletions.
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  2. lassemt created this gist Nov 24, 2020.
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    //
    // In this script we show how to fade out particles from
    // a emitter.
    //
    // Original post was created by Josh Beckwith
    // URL: https://www.facebook.com/groups/SparkARcommunity/permalink/683989935346385/
    //

    //
    // Include modules
    //
    const Scene = require('Scene');
    const Animation = require('Animation');
    const R = require('Reactive');

    // Load 'emitter0' object.
    Scene.root.findFirst('emitter0').then(emitter => {
    // emitter0 loaded and ready to be used.

    // Set start alpha to 0
    emitter.colorModulationHSVA = R.HSVA(
    1, // Hue
    1, // Saturation
    1, // Value (Brightness)
    0 // Alpha
    );

    // Animate per channel in a HSVA color model.
    // We specify a easing functions for the
    // rate of change of a channel over time.
    // More info per under channel.
    //
    // Read more about HSV color model here:
    // https://en.wikipedia.org/wiki/HSL_and_HSV
    //
    // Read more about easing functions here:
    // https://easings.net/en
    emitter.hsvaColorModulationModifier = Animation.samplers.HSVA([
    // H for hue.
    // Here we tell the Hue channel should have a constant
    // value of 1 during the lifespan of a particle.
    // So the Hue vil always stay 1 from start to finish.
    Animation.samplers.constant(1),
    // S for saturation.
    // Here we use contsant again.
    Animation.samplers.constant(1),
    // V for value.
    // And the same here.
    Animation.samplers.constant(1),
    // A for alpha.
    // Here we use a easeInQuad easing function to gradually
    // change the Alpha channel value for the particle over time.
    // The value will transition from 1 (100% visible) to 0
    // (0% visible) with a non-linear speed.
    //
    // Read more about easeInQuad here:
    // https://easings.net/en#easeInQuad
    Animation.samplers.linear(0, 1)
    ]);

    // Other particle properties that can be modified include
    // positionModifier and velocityModifier.
    // More information is specified here:
    // https://sparkar.facebook.com/ar-studio/learn/documentation/reference/classes/scenemodule.particlesystem
    });