We introduced the virtual world environment and the movement of the avatars in the beginning of the book. It is good for us to learn the fundamentals of the implementation methods and the design decision. However, when we look at the existing virtual world in detail, they are all using similar avatar movement and isometric perspective. These parts of implementation actually can be reused in different virtual world projects. We can boost up the development speed by applying some environment and movement engines to the project.
OpenSpace (http://www.openspace-engine.com/) is an isometric engine that's developed by the same company of SmartFoxServer and can fully be integrated into it.
OpenSpace comes with all basic features that an isometric engine should have such as view port panning, zooming, and 8-direction avatar's movement. Besides the basic features, there are several advanced features from this engine.