Creation of customized animated 3D content is an important issue in web-based VR/AR environments that involve users with various requirements for the content, e.g., in education, training, tourism, cultural heritage and e-commerce. 3D content customization is a complex task, as it typically covers various content features such as geometry, structure and appearance. Although a number of tools enable modeling of 3D animations, they do not support on-demand animation customization to users' requirements specified using semantic (application or domain-specific) concepts. Available solutions permit creation of 3D content in its final form, require technical knowledge and skills or are limited to a particular application domain, without possibilities to easily change the target application or domain. In this paper, we present a pipeline for creation of customized animated 3D content on the web. The pipeline uses rule-based representation of 3D content activities, which are composed into more complex animations. Animation composition is performed on-demand, using queries describing requirements in an arbitrary application domain. The use of knowledge representation adapts the approach to the current trends in the evolution of the web, including the semantic web. It enables exploration by reasoning on the content generated with users' queries. Furthermore, it permits inference of tacit properties of animations from explicitly specified properties, thereby liberating the authors from specifying all necessary animation properties. The pipeline leverages an advanced motion capture system, 3D modeling tools and game engines. We have implemented and evaluated a web-based environment for on-demand animation composition. The proposed approach can be successfully used in multiple application areas on the web, in which 3D content components are intensively reconfigured according to requirements of different users.
