This page is part of the series that explores existing software for virtual world rendering.
Unity3D is a game development ecosystem: a powerful rendering engine fully integrated with a complete set of intuitive tools and rapid workflows to create interactive 3D content; easy multi-platform publishing; thousands of quality, ready-made assets in the Asset Store and a knowledge-sharing Community (from their site).
According to Wikipedia page there are two main licenses for developers: Unity Free and Unity Pro. Unity Pro is available for US$1500. Unity Free is free as long as the user is not a commercial organization with annual gross revenues in excess of US$100,000, or an educational, academic, non-profit or government entity with a total annual budget for the entire entity in excess of US$100,000.
This was the first engine that I’ve looked into because OpenCog team has already used it in a similar project.
However, I’m expecting a steep learning curve as the engine looks quite complex. The source code being close-source is another minus.
