Render engines or render APIs are a core part of each virtual reality (VR) or augmented reality (AR) environment as well as 3D games. Most existing approaches either focus on rendering speed for high frame rates or on the presentation of advanced visual features. However, no approach exists to integrate scene descriptions based on multiple file formats without converting and thereby partly destroying the native scene format. In this paper we will present our approach of internal and external scene graphs for realizing render engines. We will show how this approach overcomes existing limitations, while still providing decent frame rates and rendering features. By using internal scene graphs for rendering, we use external scene graphs to store format or application specific information, preserving its native structure and content.

Augmented Reality (AR) technologies are rapidly expanding into new application areas. However, the development of AR user interfaces and appropriate interaction techniques remains a complex and time-consuming task. Starting from scratch is more common than building upon existing solutions. Furthermore, adaptation is difficult, often resulting in poor quality and limited flexibility with regard to user requirements. In order to overcome these problems, we introduce an infrastructure for supporting the development of specific AR interaction techniques and their adaptation to individual user needs. Our approach is threefold: a flexible AR framework providing independence from particular input devices and rendering platforms, an interaction prototyping mechanism allowing for fast prototyping of new interaction techniques, and a high-level user interface description, extending user interface descriptions into the domain of AR. The general usability and applicability of the approach is demonstrated by means of three example AR projects.

The availability of a suitable framework is of vital importance for the development of Augmented Reality (AR) and Virtual Reality (VR) projects. While features such as scalability, platform independence, support of multiple users, distribution of components, and an efficient and sophisticated rendering are the key requirements of current and future applications, existing frameworks often address these issues only partially. In our paper we present MORGAN --- an extensible component-based AR/VR framework, enabling sophisticated dynamic multi-user AR and VR projects. Core components include the MORGAN API, providing developers access to various input devices, including common tracking devices, as well as a modular render engine concept, allowing us to provide native support for individual scene graph concepts. The MORGAN framework has already been successfully deployed in several national and international research and development projects.