My animated Isomer playground. (http://jdan.github.io/isomer/playground)

playground.js

var Point  = Isomer.Point
var Path   = Isomer.Path
var Shape  = Isomer.Shape
var Vector = Isomer.Vector
var Color  = Isomer.Color

var rotationDuration = 2 * 1000
var canvas = document.getElementById("canvas")
Math.TwoPI = Math.PI * 2

function updown(factor) {
    return 1 - Math.abs(factor - .5)
}

function rotate(factor) {
    return Math.TwoPI * factor
}

var paint = function(canvas, factor) {
    var iso = new Isomer(canvas)
    
    var red = new Color(160, 60, 50)
    var blue = new Color(50, 60, 160)
    
    iso.add(Shape.Prism(Point.ORIGIN, 3, 3, 1))
    iso.add(Shape.Prism(Point(2, 0, 2 * factor + 1)), blue)
    iso.add(Shape.Prism(Point(0, 2, updown(factor) + 1)).rotateZ(Point(0.5, 2.5, 0), rotate(factor)), red)
}

var clear = function(canvas) {
    canvas.getContext('2d')
        .clearRect(0, 0, canvas.width, canvas.height)
}

var animate = function(canvas, period) {
    var pauseOffset = 0
    var startTime = performance.now()
    var paused = false
    var lastFrame = null
    var tick = function(timestamp) {
        if (paused) {
            //cancelAnimationFrame(lastFrame)
        } else {
            lastFrame = requestAnimationFrame(tick)
        }
        
        clear(canvas)
        paint(canvas, ((timestamp - startTime) % period + pauseOffset) / period)
    }

    lastFrame = requestAnimationFrame(tick)
    
    return {
        context: this,
        pause: function () {
            if (!paused) {
                paused = true
                var now = performance.now()
                pauseOffset = (now - startTime + pauseOffset) % period
                startTime = now
            }
        },
        resume: function () {
            if (paused) {
                paused = false
                startTime = performance.now()
                lastFrame = requestAnimationFrame(tick)
            }
        },
        isPaused: function () { return paused },
        getLastFrame: function () { return lastFrame },
        startTime: startTime
    }
}

window._kaleb = window._kaleb || { animations: [], paused: [] }
window._kaleb.animations.forEach(function (animation) { animation.pause && animation.pause() || window._kaleb.paused.push(animation) })
window._kaleb.animations = []

window._kaleb.animations.push(animate(canvas, rotationDuration))