“Interaction” represents a critical term in the augmented and mixed reality ecosystem. Today, in mixed reality environments and applications, interaction occupies the joint space between any combination of humans, physical environment, and computers. Although interaction methods and techniques have been extensively examined in recent decades in the field of human-computer interaction, they still should be reidentified in the context of immersive realities. The latest technological advancements in sensors, processing power and technologies, including the internet of things and the 5G GSM network, led to innovative and advanced input methods and enforced computer environmental perception. For example, ubiquitous sensors under a high-speed GSM network may enhance mobile users’ interactions with physical or virtual objects. As technological advancements emerge, researchers create umbrella terms to define their work, such as multimodal, tangible, and collaborative interactions. However, although they serve their purpose, various naming trends overlap in terminology, diverge in definitions, and lack modality and conceptual framework classifications. This paper presents a modality-based interaction-oriented diagram for researchers to position their work and defines taxonomy ground rules to expand and adjust this diagram when novel interaction approaches emerge.

Since smart devices are becoming the primary technological means for daily human activities related to user-location, location-based services constitute a crucial component of the related smart applications. Meanwhile, traditional geospatial tools such as geographic information systems (GIS) in conjunction with photogrammetric techniques and 3D visualization frameworks can achieve immersive virtual reality over custom virtual geospatial worlds. In such environments, 3D scenes with virtual beings and monuments with the assistance of storytelling techniques may reconstruct historical sites and “revive” historical events. Boosting of Internet and wireless network speeds and mixed reality (MR) capabilities generate great opportunities for the development of location-based smart applications with cultural heritage content. This paper presents the MR authoring tool of “Mergin’ Mode” project, aimed at monument demonstration through the merging of the real with the virtual, assisted by geoinformatics technologies. The project does not aim at simply producing an MR solution, but more importantly, an open source platform that relies on location-based data and services, exploiting geospatial functionalities. In the long term, it aspires to contribute to the development of open cultural data repositories and the incorporation of cultural data in location-based services and smart guides, to enable the web of open cultural data, thereby adding extra value to the existing cultural-tourism ecosystem.

We put forward a conceptualization of Mixed Reality as a blend of digital objects with real ones that coexist and interact with each other and they are also spatially referenced so that they are properly perceived in space by an observer that could potentially be at any position any time. In accordance with this statement, we have adopted the concept of a Mixed Object which is composed of a set of physical properties linked with a set of digital ones. In our case, the physical properties are acquired by employing geospatial technologies such as photogrammetry, laser scanning, unmanned aerial vehicles and positioning systems and are further processed in order to be visually displayed by utilizing Geographical Information Systems and Geovisualization frameworks in combination with traditional image processing techniques. We show that the Mixed Object approach is in conformance with Microsoft’s approach on Mixed Reality as the common space between humans, computers, and the environment and we further incorporate in these the Geospatial Linking Modalities. We finally provide an affordable MR experience as a proof of concept, by utilizing a smartphone for capturing and visualizing the environment, a visual tag for positioning purposes and freely available photogrammetrically mapped content and virtual objects to form a digital scene blended with the real environment.

Semantic Web technologies are being increasingly adopted by the geospatial community during last decade through the utilization of open standards for expressing and serving geospatial data. This was also dramatically assisted by the ever-increasing access and usage of geographic mapping and location-based services via smart devices in people’s daily activities. In this paper, we explore the developmental framework of a pure JavaScript client-side GIS platform exclusively based on invocable geospatial Web services. We also extend JavaScript utilization on the server side by deploying a node server acting as a bridge between open source WPS libraries and popular geoprocessing engines. The vehicle for such an exploration is a cross platform Web browser capable of interpreting JavaScript commands to achieve interaction with geospatial providers. The tool is a generic Web interface providing capabilities of acquiring spatial datasets, composing layouts and applying geospatial processes. In an ideal form the end-user will have to identify those services, which satisfy a geo-related need and put them in the appropriate row. The final output may act as a potential collector of freely available geospatial web services. Its server-side components may exploit geospatial processing suppliers composing that way a light-weight fully transparent open Web GIS platform.