Atlantia.tv is described as 'imation software which allows untrained users to quickly create 3D animated movies' and is an website in the Photos & Graphics category. There are more than 10 alternatives to Atlantia.tv, not only websites but also apps for a variety of platforms, including Windows, Mac, Linux, Android and iPhone. The best alternative is Blender, which is both free and Open Source. Other great sites and apps similar to Atlantia.tv are MakeHuman (Free, Open Source), Autodesk Maya (Paid), Autodesk 3ds Max (Paid) and Cinema 4D (Paid).
MakeHuman is an interactive modelling tool for creating realistic 3D human characters. These models can be exported to several computer graphics and animation platforms including Blender, Unity 3D, Unreal Engine, OpenSim and Second Life.
pixiv has released "VRoid Studio", a character maker that allows users to create, in easy steps, 3D model characters which can be used in various VR\AR platforms as well as the production 3DCG animation and games.
Clara.io is a full-featured cloud-based 3D modeling, animation and rendering software tool that runs in your web browser. With Clara.io you can make complex 3D models, create beautiful photorealistic renderings, and share them without installing any software programs.
Dead Deer is a 3D modeler, 3D game maker, and a 3D demo maker designed to create games. The scripting language allows you to code interactions in pseudo-C with the animation and synthesizes your rendering with your shaders.