Manos Kamarianakis

Manos Kamarianakis, Antonis Protopsaltis, Dimitris Angelis et al.

This work presents the introduction of UniSG^GA, a novel integrated scenegraph structure, that to incorporates behavior and geometry data on a 3D scene. It is specifically designed to seamlessly integrate Graph Neural Networks (GNNs) and address the challenges associated with transforming a 3D scenegraph (3D-SG) during generative tasks. To effectively capture and preserve the topological relationships between objects in a simplified way, within the graph representation, we propose UniSG^GA, that seamlessly integrates Geometric Algebra (GA) forms. This novel approach enhances the overall performance and capability of GNNs in handling generative and predictive tasks, opening up new possibilities and aiming to lay the foundation for further exploration and development of graph-based generative AI models that can effectively incorporate behavior data for enhanced scene generation and synthesis.

Ilias Chrysovergis, Manos Kamarianakis, Mike Kentros et al.

We present a Convolutional Neural Network (CNN) suitable to assess unconstrained surgical cuttings, trained on a dataset created with a data augmentation technique.

Prodromos Kolyvakis, Manos Kamarianakis, George Papagiannakis

This paper introduces a novel integration of Large Language Models (LLMs) with Conformal Geometric Algebra (CGA) to revolutionize controllable 3D scene editing, particularly for object repositioning tasks, which traditionally requires intricate manual processes and specialized expertise. These conventional methods typically suffer from reliance on large training datasets or lack a formalized language for precise edits. Utilizing CGA as a robust formal language, our system, Shenlong, precisely models spatial transformations necessary for accurate object repositioning. Leveraging the zero-shot learning capabilities of pre-trained LLMs, Shenlong translates natural language instructions into CGA operations which are then applied to the scene, facilitating exact spatial transformations within 3D scenes without the need for specialized pre-training. Implemented in a realistic simulation environment, Shenlong ensures compatibility with existing graphics pipelines. To accurately assess the impact of CGA, we benchmark against robust Euclidean Space baselines, evaluating both latency and accuracy. Comparative performance evaluations indicate that Shenlong significantly reduces LLM response times by 16% and boosts success rates by 9.6% on average compared to the traditional methods. Notably, Shenlong achieves a 100% perfect success rate in common practical queries, a benchmark where other systems fall short. These advancements underscore Shenlong's potential to democratize 3D scene editing, enhancing accessibility and fostering innovation across sectors such as education, digital entertainment, and virtual reality.

Manos Kamarianakis, Pandelis Sofianos, George Papagiannakis

What symbolic format should an LLM emit for reliable 3D scene editing from natural language, and does algebraic structure help beyond compact syntax? We evaluate Conformal Geometric Algebra (CGA) as a compact symbolic interface against a verbose Euclidean 4$\times$4 matrix baseline and a non-CGA Compact SE3 control in a natural-language 3D editing pipeline with controlled prompting and deterministic geometric execution. Our primary result is compositional fidelity under sequential instruction chains. In a sequence-stress protocol (20 templates, 6 trials each; $\texttt{n=120}$ outputs per method), Simple CGA and Compact SE3 both achieve 100% parse validity, but Simple CGA preserves exact ordered operation chains more reliably (97.5% vs 90.0%, two-proportion $\texttt{p=0.016}$) with lower completion-token cost (112.6 vs 133.6 tokens). This pattern is consistent with algebraic expression form supporting compositional faithfulness beyond compactness alone. A second result is confirmatory in the powered hard semantic suite ($\texttt{n=100}$ per method): compact representations (Simple CGA 45.0%, Compact SE3 42.0%, Shenlong 44.0%) all exceed the Euclidean 4$\times$4 baseline (24.0%). Simple CGA vs Euclidean is +21 pp ($\texttt{p=0.0028}$) and Compact SE3 vs Euclidean is +18 pp ($\texttt{p=0.0103}$), while Simple CGA vs Compact SE3 is statistically close ($\texttt{p=0.7755}$). Separating parse validity from geometric correctness reveals substantial optimization headroom invisible to syntax-only metrics. Overall, compact symbolic interfaces appear to drive reliability-cost gains, with CGA motor composition providing an additional advantage on ordered instruction chains. These findings inform real-time natural-language editing in immersive and interactive 3D environments.

Manos Kamarianakis, Nick Lydatakis, Antonis Protopsaltis et al.

In this work, we present an integrated geometric framework: "deep- cut" that enables for the first time a user to geometrically and algorithmically cut, tear and drill the surface of a skinned model without prior constraints, layered on top of a custom soft body mesh deformation algorithm. Both layered algorithms in this frame- work yield real-time results and are amenable for mobile Virtual Reality, in order to be utilized in a variety of interactive application scenarios. Our framework dramatically improves real-time user experience and task performance in VR, without pre-calculated or artificially designed cuts, tears, drills or surface deformations via predefined rigged animations, which is the current state-of-the-art in mobile VR. Thus our framework improves user experience on one hand, on the other hand saves both time and costs from expensive, manual, labour-intensive design pre-calculation stages.

George Papagiannakis, Walter Greenleaf, Michael Cole et al.

Computational Medical Extended Reality (CMXR), brings together life sciences and neuroscience with mathematics, engineering and computer science. It unifies computational science (scientific computing) with intelligent extended reality and spatial computing for the medical field. It significantly differs from previous "Clinical XR" or "Medical XR" terms, as it is focusing on how to integrate computational methods from neural simulation to computational geometry, computational vision and computer graphics with deep learning models to solve specific hard problems in medicine and neuroscience: from low/no-code/genAI authoring platforms to deep learning XR systems for training, planning, operative navigation, therapy and rehabilitation.

Manos Kamarianakis, Nick Lydatakis, George Papagiannakis

In this work, we propose two algorithms that can be applied in the context of a networked virtual environment to efficiently handle the interpolation of displacement data for hand-based VR HMDs. Our algorithms, based on the use of dual-quaternions and multivectors respectively, impact the network consumption rate and are highly effective in scenarios involving multiple users. We illustrate convincing results in a modern game engine and a medical VR collaborative training scenario.

George Papagiannakis, Paul Zikas, Nick Lydatakis et al.

In this work, we present MAGES 3.0, a novel Virtual Reality (VR)-based authoring SDK platform for accelerated surgical training and assessment. The MAGES Software Development Kit (SDK) allows code-free prototyping of any VR psychomotor simulation of medical operations by medical professionals, who urgently need a tool to solve the issue of outdated medical training. Our platform encapsulates the following novel algorithmic techniques: a) collaborative networking layer with Geometric Algebra (GA) interpolation engine b) supervised machine learning analytics module for real-time recommendations and user profiling c) GA deformable cutting and tearing algorithm d) on-the-go configurable soft body simulation for deformable surfaces.