We can safely say that creating flash animations for a site is the last century. How common is D animation on the web Creating D animations requires more resources both temporary and financial. In addition its use imposes an even greater responsibility on the specialist engaged in optimizing the web platform.
This is because a page with D can weigh much more than with a D animation which means delaying the user s first "contact" time with content and increasing the risk of failure. But this does not happen if you use the appropriate development tools and throw mobile app designs service your energy at optimization. You can create D animation on the site in the programs: after effects; ds Max (mainly used for game development); Cinema D.
If the site has D animation dudes are generally awesome. As for me it is more common on the sites of design agencies and in product design. For example a volumetric model of a bicycle is created to show it in motion. D animation is common but more like a graphic element a three dimensional picture / illustration or just an object as a background.