Designing high-quality interactive 3D spaces, such as those required for professional training, is a complex, expensive, and time-consuming task. Although several approaches have been proposed to simplify the process, the result is always a trade-off between advanced capabilities and the ease of use of the content creation tool. To guarantee high visual quality of the modeling results, no simplification of the geometry detail level is possible. In this paper, we propose a method of visual content design, which simplifies the process by eliminating some of the structural complexity through the introduction of content controllers, which based on the known semantics of content objects introduce specific editing rules and impose a specific structure of their sub-components, thus simplifying and speeding up the content creation process as well as eliminating common mistakes.