////  rain.js//  examples////  Created by David Rowe on 9 Apr 2015.//  Copyright 2015 High Fidelity, Inc.////  Distributed under the Apache License, Version 2.0.//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html// var RainSquall = function (properties) {    var // Properties        squallOrigin,        squallRadius,        dropsPerMinute = 60,        dropSize = { x: 0.1, y: 0.1, z: 0.1 },        dropFallSpeed = 1,                                      // m/s        dropLifetime = 60,                                      // Seconds        dropSpinMax = 0,                                        // Maximum angular velocity per axis; deg/s        debug = true,                                          // Display origin circle; don't use running on Stack Manager        // Other        squallCircle,        SQUALL_CIRCLE_COLOR = { red: 255, green: 0, blue: 0 },        SQUALL_CIRCLE_ALPHA = 0.5,        SQUALL_CIRCLE_ROTATION = Quat.fromPitchYawRollDegrees(90, 0, 0),        raindropProperties,        RAINDROP_MODEL_URL = "https://s3.amazonaws.com/hifi-public/ozan/Polyworld/Sets/sky/tetrahedron_v1-Faceted2.fbx",        raindropTimer,        raindrops = [],                                         // HACK: Work around raindrops not always getting velocities        raindropVelocities = [],                                // HACK: Work around raindrops not always getting velocities        DEGREES_TO_RADIANS = Math.PI / 180;     function processProperties() {        if (!properties.hasOwnProperty("origin")) {            print("ERROR: Rain squall origin must be specified");            return;        }        squallOrigin = properties.origin;         if (!properties.hasOwnProperty("radius")) {            print("ERROR: Rain squall radius must be specified");            return;        }        squallRadius = properties.radius;         if (properties.hasOwnProperty("dropsPerMinute")) {            dropsPerMinute = properties.dropsPerMinute;        }         if (properties.hasOwnProperty("dropSize")) {            dropSize = properties.dropSize;        }         if (properties.hasOwnProperty("dropFallSpeed")) {            dropFallSpeed = properties.dropFallSpeed;        }         if (properties.hasOwnProperty("dropLifetime")) {            dropLifetime = properties.dropLifetime;        }         if (properties.hasOwnProperty("dropSpinMax")) {            dropSpinMax = properties.dropSpinMax;        }         if (properties.hasOwnProperty("debug")) {            debug = properties.debug;        }         raindropProperties = {            type: "Model",            modelURL: RAINDROP_MODEL_URL,            lifetime: dropLifetime,            dimensions: dropSize,            velocity: { x: 0, y: -dropFallSpeed, z: 0 },            damping: 0,            angularDamping: 0,            collisionless: true        };    }     function createRaindrop() {        var angle,            radius,            offset,            drop,            spin = { x: 0, y: 0, z: 0 },            maxSpinRadians = properties.dropSpinMax * DEGREES_TO_RADIANS,            i;         // HACK: Work around rain drops not always getting velocities set at creation        for (i = 0; i < raindrops.length; i += 1) {            Entities.editEntity(raindrops[i], raindropVelocities[i]);        }         angle = Math.random() * 360;        radius = Math.random() * squallRadius;        offset = Vec3.multiplyQbyV(Quat.fromPitchYawRollDegrees(0, angle, 0), { x: 0, y: -0.1, z: radius });        raindropProperties.position = Vec3.sum(squallOrigin, offset);        if (properties.dropSpinMax > 0) {            spin = {                 x: Math.random() * maxSpinRadians,                y: Math.random() * maxSpinRadians,                z: Math.random() * maxSpinRadians            };            raindropProperties.angularVelocity = spin;        }        drop = Entities.addEntity(raindropProperties);         // HACK: Work around rain drops not always getting velocities set at creation        raindrops.push(drop);        raindropVelocities.push({            velocity: raindropProperties.velocity,            angularVelocity: spin        });        if (raindrops.length > 5) {            raindrops.shift();            raindropVelocities.shift();        }    }     function setUp() {        if (debug) {            squallCircle = Overlays.addOverlay("circle3d", {                size: { x: squallRadius, y: squallRadius },                color: SQUALL_CIRCLE_COLOR,                alpha: SQUALL_CIRCLE_ALPHA,                solid: true,                visible: debug,                position: squallOrigin,                rotation: SQUALL_CIRCLE_ROTATION            });        }         raindropTimer = Script.setInterval(createRaindrop, 60000 / dropsPerMinute);    }     function tearDown() {        Script.clearInterval(raindropTimer);        if (debug) {            Overlays.deleteOverlay(squallCircle);        }    }     processProperties();    setUp();    Script.scriptEnding.connect(tearDown);     return {    };}; var center = Vec3.sum(MyAvatar.position, Vec3.multiply(3, Quat.getFront(Camera.getOrientation())));center.y += 10;var rainSquall1 = new RainSquall({    origin:center,    radius: 25,    dropsPerMinute: 120,    dropSize: { x: 0.1, y: 0.1, z: 0.1 },    dropFallSpeed: 3,    dropLifetime: 30,    dropSpinMax: 180,    debug: false});