Develop Reference

How Greensock animations work under the hood that it's so performant?

There's a speed test in greensock website comparing speed with other animations libraries, JQuery or Even CSS Transitions. It's benchmarking FPS by animating hundreds/thousands of perticles.
The FPS of greensock animations outnumbered everything else. Css transitions & JQuery is not much close to greensock.
I tried searching about greensock but couldn't find much useful information. Most of them aren't explained well.
I'm still a amateur in javascript. If I try to make my own JS animations, those won't be as fast as gsap. Not even close. So it would be great to know what happens underneath the hood. How they optimize that much!

Jack (the creator of GreenSock) tells how GSAP is so fast in this forum post among other places. To recap some of the points there:
Use highly optimized JavaScript across the board (this entails many things like using linked lists, local variables, quick lookup tables, inlining code, bitwise operators, leveraging prototypes instead of recreating functions/variables for each instance, etc.)
Engineer the structure of the platform so that it lends itself very well to high-pressure situations, minimizing function calls and making sure things are gc-friendly.
Make updates in a single update loop that's driven by requestAnimationFrame, only falling back to setTimeout() if necessary.
Cache some important values internally for faster updates.
For CSS transforms, we calculate matrix values and construct either a matrix() or matrix3d() when there's any rotation or skewing because our tests showed that it was faster.
There's no silver bullet that makes it fast. It just is smart in the way that it does things based on over a dozen years of experience.

Velocity.js' very low performance

I just changed the animation engine for one of the websites I'm currently working on from Jquery Transit to Velocity.js. I simply changed transition() to velocity() and while it is working, the animations rendered by Velocity.js perform much worse (than Transit's). With Transit I get almost perfect 60fps and correct timing, while Velocity gives me less than 10 fps and the animation speed seems to be incorrect. Velocity's animations give an impression of being heavy and sluggish in comparison to Transit, but in theory Velocity should perform better.
Does anybody have an idea what the problem could be? Could it be that it conflicts with slick.js (carousel), which is also present on that site?
Here's an excerpt of the syntax I use, nothing out of the ordinary, I think.
$contactOverlay.velocity({ height: '100%' }, 300);
Thanks for all your help.

Velocity.js doesn't perform well if it's used together with other Animation-Libraries, like jQuery's animations (especially when they are active at the same time). Make sure Velocity.js is the only thing that is animating elements on your page.
In my experience, pure CSS-Animations shouldn't be a problem, though.

Use Javascript or CSS3 for animations?

I have been wondering what's better for animation in terms of performance - Javascript or CSS3.
On this page you have a comparision between GSAP, jQuery and CSS3:
http://css-tricks.com/myth-busting-css-animations-vs-javascript/
Scroll down to performance comparision. Now my Question is the following:
Will CSS3 sooner or later be faster than Javascript(GSAP in this case)? So should we program animations with CSS3 or still with Javascript?
Update: Another website:
http://greensock.com/transitions/
As it looks right now, GSAP is faster than CSS3 in most ways, but in 3D transforms CSS3 is faster.
The question now still is: Will CSS3 be faster than GSAP(or other comparable frameworks)?

CSS3 animations are faster and smoother than JavaScript animations because they can be optimised and potentially hardware accelerated by the browser/GPU. JS animations on the other hand are usually a little less smooth because each frame of the animation has to be explicitly interpreted an rendered.
Also, JS animations are used mainly for older browsers which don't support CSS3, which is relatively new.

Here's an approximation of how animations work:
CSS3: "Please transition this as smoothly as reasonably possible."
JavaScript (naive): "Okay, so first you move here, then you move here, then here... are you keeping up?" [Browser:] "MAKE UP YOUR MIND!"
JavaScript (delta timing): "Okay, move here. Damn, you're slow. Okay, move over here so it looks like you're not lagging."
jQuery: "I don't care how it's done, just do it. Bye!"
The winner, in my opinion, is CSS3.

It seems that there are only four css properties that get real hardware acceleration as Paul Lewis and Paul Irish explain here: http://www.html5rocks.com/en/tutorials/speed/high-performance-animations/ (very interesting read!).
Those are: position, scale, rotation and opacity
All other css properties get nothing in most browsers and might therefore be slow.
So yes, some CSS animations are already super smooth and the rest will get faster in time.
Especially on mobile devices. (More technical stuff in the other answers)
But soon after that happens, libraries like GSAP and jQuery will (under the hood) change their animation method anyway. They could even choose the method that is faster depending on the device the site is running on.
(For example: You can already use the transit plugin for jQuery to use CSS3 animations from jQuery. http://ricostacruz.com/jquery.transit/)
So:
Will CSS3 be faster than Javascript?
Yes. But:
Should we program animations with CSS3 or still with Javascript?
That is a diffent story and depend on your needs.
If you animate a little hover effect using opacity: The CSS3 is probalby your way to go. Easy, clean, fast.
For complex animations, different interactions, etc. you will need to use JS which also gives you the flexibility of choosing the animation method later on.
Especially GSAP is ridiculous powerful and easy to write.

CSS3 vs Javascript/jQuery [duplicate]

I'm working on an iPad HTML5 app and I've already implemented ontouch support to trigger events faster and I'm using jQuery to target the elements easier, but for the animations I'm using CSS3 transitions
What do you think is faster? using jQuery animations since I already have imported the library or use CSS3 transitions when targeting elements with jQuery?

According to this link, jQuery animation is much slower then css animation.
Reason can be because jquery has to modify the props of the DOM element using timers and a loop. The CSS is part of the browser engine . which depends pretty much on hardware of system. You can also check that in profiling of Chrome or Firefox.

CSS animations will almost always be faster.
A head to head comparison of CSS transitions and jQuery's animate.
Rather than setting a timer to run repeatedly, transitions are handled
natively by the browser. In my rather unscientific testing,
transitions are always quicker, running with a higher frame rate,
especially with high numbers of elements. They also have the advantage
that colours can be animated easily, rather than having to rely on
plugins.
http://css.dzone.com/articles/css3-transitions-vs-jquery
Related Question:
Performance of CSS Transitions vs. JS animation packages

CSS3 Transitions should be faster because they are native to the browser.

Its css3 its faster and consumes lesser memory and is smoother.
CSS processor is written in C++ and native code executes very fast whereas jQuery (JavaScript) is an interpreted language and the browser can't predict JavaScript ahead in time.
http://dev.opera.com/articles/view/css3-vs-jquery-animations/
View the above link to know about the experiments held over CSS3 vs jQuery

This article (http://css-tricks.com/myth-busting-css-animations-vs-javascript/) does an excellent comparison of CSS transforms vs. jQuery animations vs. GSAP (another JavaScript library).
CSS animations are significantly faster than jQuery. However, on most devices and browsers I tested, the JavaScript-based GSAP performed even better than CSS animations
So CSS transforms are faster than jQuery animations, but don't let this make you assume that CSS transforms are faster than JavaScript. GSAP shows that JavaScript can outperform CSS.

CSS3 will be faster as it comes standard with the browser where as JQuery is another file that has to be loaded, however I have found that depending on the animation that JQuery can run a lot smoother. Sometimes it's also nice to experiment with pure Javascript now and again.

The Mozilla developer documentation raises some interesting points regarding CSS3 animation:
Letting the browser control the animation sequence lets the browser
optimize performance and efficiency by, for example, reducing the
update frequency of animations running in tabs that aren't currently
visible.
WebKit (which powered Safari) also makes use of hardware accelerated compositing, which can have a much greater effect on performance than anything Javascript can do at this time. (I think this will change very soon though as more functions are added to manage calculations) This is because it will take advantage of dedicated hardware if it available to perform the calculations, rather than making it happen through a translated language like Javascript.
I am not 100% certain whether WebKit on the iPad is hardware accelerated; however it would stand to reason that because it is standardized and increasing in popularity, that this would only improve with time.

From here
A head to head comparison of CSS transitions and jQuery's animate.
Rather than setting a timer to run repeatedly, transitions are handled natively
by the browser.
In my rather unscientific testing, transitions are always quicker, running with a
higher frame rate, especially with high numbers of elements. They also have the
advantage that colours can be animated easily, rather than having to rely on
plugins.
A test here along with this conclusion.
Javascript animations based on timers can never be as quick as native
animations,
as they don't have access to enough of browser to make the same optimisations.
These animations should be used as a fallback only in legacy browsers.
Also notice this,
CSS3 animations are terriffic but do use a lot of your processor’s
power.
There is no way to fine tune the animation with CSS3 the same way you can using a
framework like jQuery. So, as long as CSS3 animations aren’t CPU friendly you
better stick with jQuery.

If you're using jQuery/javascript animation with the canvas tag (which if I'm not mistaken still relies upon a timer... new to playing around with it though), then it gives you the advantage of hardware acceleration with javascript. If you're just looking to move something around when you hover then transitions work great. CSS transitions may run a little smoother but it's a trade off, you're relinquishing a ton of javascript control over the animation by using transitions. I like to keep style in CSS and behavior in JS - isn't that how it's supposed to work anyway? CSS transitions kind of broke that logic...

Native is supposed to be faster, but if browser developers are sloppy (or lazy), they write bad code, which leads to poor results with CSS animations (or transitions).
Nowadays, jQuery has a plugin which overides the "animation" function with an "improved" one. see Velocity. I'm not getting into other ways to animate the DOM with javascript because it's outside the scope of this question.
So, as-is, jQuery is slower than CSS. also, CSS is easier to write because you already have the element style probably, so adding a few rules is easy, compared to a situation where you need to start writing JS somewhere and manage it..but for complex, heavy stuff, JS is faster, sadly.
A very good article about this exact question - http://davidwalsh.name/css-js-animation

For quick Web Animations, Javascript/jQuery or CSS3?

jQuery animations seem to have better browser support, but the CSS3 Keyframes appear to be really fast and smooth yet not very good browser support.
I'd like to here people's opinion about jQuery or CSS3 in terms of:
Canvas Gaming:
I have seen a few CSS3 games which where pretty nice. Then again, when we are gaming with the Canvas we are already using Javascript and to do some quick and dirty stuff we might also include the jQuery Javacsript Library.
Or would we use both for Canvas Gaming? Not sure.
Websites:
For normal websites delivering content, not gaming: what would be a decent approach for animations on a regular Web Page?
I also hear stuff such as: CSS3 Animations slows down some jQuery Animations and other scripts on the page...hm.
To clear things up, I would just someone to explain some of the advantages of using CSS3 Animations or a jQuery Animation.
Any opinions would be nice, thanks!

The Mozilla developer documentation raises some interesting points regarding CSS3 animation:
Letting the browser control the animation sequence lets the browser
optimize performance and efficiency by, for example, reducing the
update frequency of animations running in tabs that aren't currently
visible.
WebKit also makes use of hardware accelerated compositing, which can have a much greater effect on performance than anything Javascript can do at this time. (I think this will change very soon though as more functions are added to manage calculations) This is because it will take advantage of dedicated hardware if it available to perform the calculations, rather than making it happen through a translated language like Javascript.
It stands to reason browser vendors will only increase their support for this in the name of competition, and because the CSS3 standard is getting closer to completion.
My only concern would be the manageability of the code, although this could easily be managed with a decent translation layer. There are some excellent animation engines available in Javascript, although I haven't used or researched one recently to give an accurate estimate of performance.

For the part of your question Re: "Websites: For normal websites delivering content", you are going to want to interact with a server for some of that content. That interaction is going to be via ajax and, based on your question, jquery-based. Then consider some of your animations will be based on the exact data returned.
jQuery makes that kind of content-dependent animation so easy. In a "normal website delivering content" you would, logically, have much less animation than in a game - so performance / resource hogging is less of an issue.