3d visualisation of real spaces in the Internet is nowadays getting ready for all day usage. Because of higher complexity of 3d- compared to 2d visualisation, it is mostly used for high-end visualisations. The strategy of integrating them into existing spatial data infrastructures and making reuse of existing resources that are so far mostly used for 2d visualisation, created the opportunity to build 3d web-applications as an add-on. The recurring problems of web-based 3d visualisation raised the question, how special modules for 3d visualisation could also be made reuseable. We took a closer look especially on the so-called mapping-level, which is essential for the type of visualisation, interactivity and some special analysis-tasks.