We present a low-cost, custom-built eye tracking system designed as a modular add-on for augmented reality (AR) headsets that either lack native eye tracking capabilities or provide insufficient ocular data for cognitive monitoring. Our system leverages infrared-enabled cameras and machine learning techniques to extract oculometric features-pupil diameter, blink dynamics, and saccadic velocity-in real time, enabling reliable detection of user mental fatigue. Unlike commercial high-cost solutions or restricted APIs of built-in AR trackers, the proposed device provides direct access to raw eye metrics under diverse conditions. We implement an unsupervised clustering approach combined with supervised classifiers to estimate fatigue levels on a persecond basis, integrating both self-reports and objective eye tracking data. Results are streamed into the AR environment, where individual and team-wide fatigue states are visualized through intuitive holographic overlays. This collaborative monitoring framework enables users to track both their own and others' cognitive states, supporting adaptive interventions in shared AR tasks. The system demonstrates the feasibility of affordable, portable, and extensible ocular-based fatigue detection for enhancing performance, safety, and well-being in group-oriented AR applications.

Understanding and modeling the complex geometries of the natural world is a key challenge in the Geosciences. Representing terrains, subsurfaces, catchments, and environmental domains requires not only accurate data acquisition but also robust and flexible geometric modeling tools. While computer graphics and geometry processing have made significant advances in representing and manipulating complex 2D and 3D shapes, their uptake in environmental modeling remains limited due to the lack of geoscientific constraints and interoperability with geospatial standards. We present MUSE-geometry, a lightweight computational geometry tool designed to bridge this gap. Our tool integrates geometric primitives, structured and unstructured meshing, and editing operations with explicit support for geospatial data formats and coordinate reference systems. By combining computational geometry with geospatial awareness, the tool enables the creation of simulation-ready 2D/3D models that preserve input integrity and topological consistency. Implemented as a selfcontained command-line application in C++, our tool has been tested on real-world scenarios, including modeling topographic surfaces or coastal water volumes, demonstrating its ability to unify data structures and geometric processing within a single pipeline. The tool offers flexible and interoperable operations that enhance the integration of advanced geometric processing into geoscientific workflows in compliance with geospatial standards.

In recent years, Computer Graphics (CG) and related techniques have become increasingly important for the preservation and dissemination of Cultural Heritage (CH). Here we present a set of three excellent CH reconstructions and virtual heritage experiences created by final year undergraduate students from several computer animation related programmes of study in the course of an optional course on “CG and Animation for Cultural Heritage”. The three projects discussed here are interactive heritage experiences, including a reconstruction of the tomb of Tutankhamun, an Augmented Reality (AR) reconstruction of the Iron Age hillfort Maiden Castle, and a Virtual Reality (VR) reconstruction of ancient Stonehenge.

In this work we present a novel free-hand gesture user interface based on detecting the trajectory of fiducial markers attached to the user's fingers and pulse, able to interact a sequence of images of a digital video piece. The model adopted for the video representation, is based in its decomposition in a sequence of frames, or filmstrip. Totally sensor-less and cable-less interfaces, provide the means for a user to intuitively interact through gestures with the filmstrip, within the framework of an Augmented Virtuality usage scenario. By simply gesturing, users are able to select at random, drag, release, delete or zoom image frames, browse the filmstrip at a controlled user-defined rate and issue start, end, stop and play commands to better control the digital video sequence. A fixed video camera monitors the user interaction through gesturing of the mentioned fiducial markers. This scheme enables the system to simplify the more complex problem of marker-less free-hand gesture tracking. Once the markers are detected and recognized in real- time by the computer vision layer, the system obtains the 3D pose (position and orientation) of the marker centres in relation to a virtual camera reference frame, whose mathematical model matches the real video camera. We are specifically interested in obtaining the pose of the left and right hand pulses, left and right thumb, and left and right hand index. By projecting the positions of these poses in the 2D visualization window, simple topological analysis based in the study of the kinematics evolution of distances and angles, can be implemented, enabling gesture recognition and the activation of system functions and, subsequently, of specific gesture-based user interaction for a given active functionality. This interaction will affect the shape, scale factor, position and visualisation of scene objects, that is, of filmstrip frames. For the computer vision layer, our system adopts AR Toolkit, a C/Open GL-based open source library that uses accurate vision based tracking methods to determine the virtual camera pose information through the detection in real-time of fiducial markers. The graphical output is implemented with C++/Open GL. Our proposed system is general, in the sense that it can interact with any filmstrip, obtained ''a priori'' from a digital video source.

Splat-based rendering techniques produce highly realistic renderings from 3D scan data without prior mesh generation. Mapping high-resolution photographs to the splat primitives enables detailed reproduction of surface appearance. However, in many cases these massive datasets do not fit into GPU memory. In this paper, we present a compression and rendering method that is designed for large textured point cloud datasets. Our goal is to achieve compression ratios that outperform generic texture compression algorithms, while still retaining the ability to efficiently render without prior decompression. To achieve this, we resample the input textures by projecting them onto the splats and create a fixed-size representation that can be approximated by a sparse dictionary coding scheme. Each splat has a variable number of codeword indices and associated weights, which define the final texture as a linear combination during rendering. For further reduction of the memory footprint, we compress geometric attributes by careful clustering and quantization of local neighborhoods. Our approach reduces the memory requirements of textured point clouds by one order of magnitude, while retaining the possibility to efficiently render the compressed data.

This paper presents a portable application to visualize performance data obtained from GPS devices in outdoor sports (e.g., ski, running, BTT) that also record data as heartbeat rate. GPS file formats are analyzed and a data structure that enables easy and flexible data manipulation is presented. Several data representation (chart, map and table) and visualization issues are addressed. Results show that the set of interaction design requirements was appropriate. The application is portable to due the development tools adopted (OpenGL, GLUI and TinyXML).

Sistemas de assistência à condução e navegação em automóveis tornaram-se ubíquos nos últimos anos. No entanto, o modo de interacção mais comum destes sistemas foi avaliado por diversos estudos como tendo um considerável potencial de distracção e de risco da segurança. Modelos alternativos de interacção têm sido apresentados na academia e na indústria, melhorando aspectos de atenção e de usabilidade, mas continuam a apresentar insuficiências que podem prejudicar a sua eficácia e segurança. Este projecto avalia uma potencial abordagem a dispositivos de assistência a navegação, baseada num head-up display (HUD) projectado no pára-brisas do carro, associado a uma componente de realidade aumentada (AR) para apresentar informação de navegação directamente sobreposta à rede viária.

With the growing demand for real-time collaboration in distributed immersive environments, e.g. in mechanical engineering or health care, a need for synchronisation of user's fine motor movements is gaining significance. This paper presents the evaluation of several popular optimization strategies for synchronization of fine motor movements. The evaluation was performed using a dedicated simulation software which recorded several network metrics and transformation errors. Fine motorics included hand and finger movements, which were recorded using the finger tracking system Leap Motion. It was shown that a combination of Cubic Hermite Spline Interpolation for spatial positions and Squad Interpolation for spatial rotations with Local Lag for time synchronization provided the smallest average position error among all clients at a 10 Hz tick rate.

The rapid technological advances in computing and computer graphics of the past three decades have in turn fueled the proliferation of the use of these technologies for Cultural Heritage. Formal educational courses for the application of computer graphics to Cultural Heritage are few and far between, and the courses that do exist tend to be targeted at archaeology students, with hardly any courses catering to computing or computer graphics students. To address this gap in education provision, we introduce a final year undergraduate course on ''CG and Animation for Cultural Heritage'', which provides students on technical and art & design computer graphics and animation courses with a broad introduction to the creation of Cultural Heritage applications of CG and animation techniques more commonly found in digital entertainment and visual effects. In this paper we describe this course and its curriculum and discuss its outcomes.