Procedural Content Generation methods enable the creation of varied content algorithmically. One such method is Wave Function Collapse (WFC), a tile-based local constraint solver commonly applied to texture, map and level generation for grid-based content; it is able to create varied output from the same set of rules, usually derived from an input sample. However, a glaring limitation of WFC is that it only operates on tiles of the same shape and size. We propose Non-Uniform Tile Wave Function Collapse (nutWFC), an extension of WFC that supports multi-cellular tiles with varying shapes and sizes, so-called Non-Uniform Tiles (NUTs). Familiar examples of such tiles can be found in LEGO ® and Tetris. The algorithm guarantees NUT shape and size preservation even under WFC's Overlapping Model in three dimensions. We show that nutWFC is a super-set of WFC that harmonizes strict NUT shape and size constraints with WFC's output diversity without significant performance penalties. We illustrate the expressive power of nutWFC with a few results that explore the advantages of NUTs and would therefore not be feasible with WFC.

Frontotemporal dementia (FTD) is the second most common cause of young-onset dementia and is typically caused by frontal and/or temporal lobe degeneration [1]. This degeneration impacts personality, judgment, and the ability to recognize emotion. Early diagnosis of FTD is critical for effective treatment, but current diagnostic tools often lack the realism necessary to assess social cognitive abilities like emotion recognition and theory of mind. We propose the customization of an immersive virtual reality (VR) experience to improve early FTD diagnosis by creating realistic social interactions in immersive environments. Our approach is two-fold: (i) an authoring tool that gives neuropsychologists generative AI support for writing a suitable dialog involving faux pas, picking characters and voicing them; (ii) a VR game in which patients observe the enactment of those scripted social scenarios, guided by a virtual companion. We discuss the main features of our current prototype, and identify some development and evaluation challenges ahead.

Psychometric properties of Tommy's Quest (TQ), a novel serious game to evaluate Theory of Mind (ToM) and the pen-and-paper Faux Pas Test (FPT) were assessed. Results from 67 cognitively unimpaired individuals indicated that TQ had adequate construct validity, internal consistency and test–retest reliability. Participants performed worse on TQ compared to the FPT, suggesting greater sensitivity to subtle deficits. These findings support serious games like TQ as a promising tool for ToM assessment, highlighting the need for clinical validation.

The success of climate adaptation and nature conservation measures depends significantly on public support. Although the value of protecting iconic species is often easy to communicate to non-expert audiences, conveying the broader importance of ecosystem restoration and conservation for climate resilience is more challenging. To address this, we developed a method that combines spatially explicit models of complex, self-organizing ecosystems with state-of-the-art visualization techniques. This approach creates immersive, three-dimensional panoramic views of natural landscapes, illustrating how people live in and interact with these ecosystems. Our method showcases the inherent complexity of ecosystems, highlighting features such as spatial patterning and the dynamic processes that shape them, as well as the critical role of this complexity in supporting biodiversity. Additionally, it demonstrates the potential of restored or even constructed ecosystems as nature-based solutions to future climate challenges. Adaptable to various ecosystems and locations, with the optional addition of audio or text explanations, this visualization tool can be used in diverse contexts, from museum exhibits to on-site virtual experiences, effectively reaching broad audiences. We present our visualization approach through two case studies that bring to life past climate-adaptive ecosystems and envision future developments. The first case depicts a historic medieval village, now located within a low-lying polder, which was once founded on an expansive, climate-resilient marsh that naturally rose with sea levels due to continuous sediment deposition. The second case explores a planned nature restoration project in Biesbosch National Park, where an embanked meadow is planned to be converted into a tidal wetland.

Holonomy is a virtual environment based on the mathematical concept of hyperbolic geometry. Unlike other environments, Holonomy allows users to seamlessly explore an infinite hyperbolic space by physically walking. They use their body as the controller, eliminating the need for teleportation or other artificial VR locomotion methods. This paper discusses the development of Holonomy, highlighting the technical challenges faced and overcome during its creation, including rendering complex hyperbolic environments, populating the space with objects, and implementing algorithms for finding shortest paths in the underlying non-Euclidean geometry. Furthermore, we present a proof-of-concept implementation in the form of a VR navigation game and some preliminary learning outcomes from this implementation.

As one of the most disruptive human-computer interaction techniques, Virtual Reality (VR) provides a novel way to examine human movements, e.g. when investigating Body Ownership (BO) in the field of cognitive sciences, especially when the visual output diverges from real-world actions. Previous research in BO uses questionnaires and brain imaging, where the former is a highly subjective metric, and the latter is very costly in time, money, and personnel. To answer the question How can a VR serious game help overcome current challenges of BO assessment?, we designed Astral Body, a VR game that helps cognitive science researchers assess people’s level of BO. In the game, players are asked to grab ‘flying collectibles’ coming from a portal in space. Researchers can inject different types and levels of asynchrony into the arms of the visualized avatar, thus affecting the players’ BO experience and perception. Players, in turn, can also report whenever they perceive possible mismatched avatar behavior. In addition, researchers can analyze player data, including looking for unconscious responses, e.g. small adjustments in physical movements to mitigate injected asynchrony. Preliminary results from playtesting and qualitative analysis of Astral Bodyindicate that a VR game can effectively help researchers investigate BO phenomena.

Learning motor skills is essential to many different aspects of life, from big movements needed for sports to small and simple movements used in the rehabilitation of stroke patients. In recent years, sonification, i.e. using sounds as feedback for actions, has been researched as a promising technique for studying motor behavior. In particular, we explore how to use sonification to make the process of learning motor skills accessible and engaging. We posit that an interactive and gamified environment can increase the engagement in that process. Moreover, an enjoyable setting is more likely to stimulate repetition, an indispensable feature of any learning endeavor. We, therefore, designed and developed Pizzicato, a rhythm-based serious game that leads players to move their arms and hands to actively play music. The game uses a common webcam to track your hand movements: pinching one finger to the thumb at the right position and moment will play musical notes that pleasantly add up to a full musical track. Our player tests have shown that players find Pizzicato accessible and engaging, and report that playing the game gives them a strong sense of agency. Pizzicato was developed in collaboration with neuropsychology colleagues, who are now starting to use it as a flexible tool for motor behavior research, both for diagnostic and rehabilitation purposes.

A narrative world typically consists of several interrelated locations that, all together, fully support enacting a given story. For this, each location in a narrative world features all the objects as required there by the narrative, as well as a variety of other objects that plausibly describe or decorate the location. Procedural generation of narrative worlds poses many challenges, including that, First, it cannot lean only on domain knowledge (e.g., patterns of objects commonly found in typical locations), and, second, it involves a temporal dimension, which introduces dynamic fluctuations of objects between locations. In this article, we present a novel approach for the procedural generation of narrative worlds, following two stages: first, a narrative world mold is generated (only once) for a given story; second, the narrative world mold is used to create one (or more) possible narrative worlds for that story. For each story, its narrative world mold integrates spatio-temporal descriptions of its locations with the object semantics and the domain knowledge previously acquired on typical locations. We describe how a narrative world mold can be generated, as well as how it can be fed to existing procedural generation methods, to create a variety of narrative worlds that fit that narrative. We evaluate our own implementation of this approach, performing a number of experiments that illustrate both the expressive power of narrative world molds and their ability to steer the generation of narrative worlds.

There are few proposals to improve the interactivity and control of wave function collapse (WFC) in a mixed-initiative setting. Moreover, most WFC algorithm variants operate on an simple, unstructured set of tiles. This limitation on the level of control provided to designers hampers their creative work in various ways. We propose Hierarchical Semantic WFC, a generalized approach to WFC that organizes its tile-set into a hierarchy akin to a taxonomy induced by the relation 'consists-of'. In such a hierarchical structure, abstract tiles (i.e. non-leaf nodes) can represent the first sketchy intentions of a designer (e.g. forest, urban, desert,...) This allows a designer to interactively collapse a given area into abstract tiles, while subsequently, (and repeatedly, if desired) WFC can resolve each area into a variety of particular instances, by further collapsing it into (a valid combination of) its children tiles (whether leaves or not). We identify how this subtle tile-set change affects the whole WFC algorithm, describe a number of novel exploratory and interactive functions that this enables, and showcase these with a variety of examples generated with our prototype implementation. We conclude that these new mixed-initiative content generation methods can considerably reduce design iteration times and improve the assistance given to designers in expressing their creative intent.

Conventional gait rehabilitation methods have the risk of alienating the patient due to their monotonous nature, thus negatively impacting the effectiveness of gait training. Modern technologies can help provide patients with better support, safety and immersive experience during training. However, physiotherapists cannot be required to master those technologies, nor to spend much time designing a more varied and engaging treatment for each patient. In this paper, we argue that adaptive gamified gait rehabilitation based on procedural content generation (PCG) can effectively support physiotherapists in achieving such customized outcomes. We propose a generic adaptation scheme to steer the generation of movement challenge levels based on player modeling and therapists' intervention. Our approach features two difficulty adjustment strategies: parameter progression schemes and integration of multiple therapy goals. These strategies are applicable to the personalization of a wide range of gait rehabilitation goals. We implemented this approach in a standalone prototype for supporting gait training with the RYSEN system, a three-dimensional overground body weight support system. From our assessment with physiotherapists, we conclude that our PCG-based adaptive method effectively assists therapists in (i) offering a broad diversity in gait exercises to a wide group of patients, and (ii) dynamically tailoring challenge levels for a variety of gait tasks.

Mostly, restorative environments, like parks and forests, are only thought of in the real world. However, one can wonder whether their restorative effects translate to a virtual world; and whether the environment itself makes any difference. In order to assess the possible translation of restorative properties from the real world to a virtual setting, we developed Resto Quest, a single-player, first-person exploration game, designed to investigate the possible restorative effects of both natural and urban virtual environments. Resto Quest is playable on a normal personal computer, and its main game play loop consists of exploring the environment, locating in it a task to accomplish, and completing a simple minigame. After completion of each minigame, a positive change in the scenery takes place. Evaluation of Resto Quest has shown that players found its game mechanics relaxing, and that the minigames offer balanced difficulty between two interchangeable environments.

Wave Function Collapse (WFC) is a powerful generative algorithm, able to create locally-similar output based on a single example input. One of the inherent limitations of the original WFC is that it often requires users to understand its inner workings, and possibly make their own ad-hoc mods, to achieve satisfactory results. Besides distracting from your creative task, this strongly reduces the algorithm's effective usefulness to a small group of technical users. We propose miWFC, a novel mixed-initiative approach to WFC aimed at overcoming these drawbacks. Its main focus is on providing intuitive control to its users, in a way that matches their usual creative workflow. Among its main features, this approach provides (i) interactive navigation through design history, including controlled backtracking, (ii) precise manual editing of the output for direct expression of design intent, and (iii) interactive manipulation of tile weights, to tweak the global appearance of the output. We evaluated a prototype implementation of our approach among game artists and other creative professionals, and concluded that its features were largely considered useful and supportive of their creative work.

Several datasets of stories and text have been proven useful for a variety of research fields. Yet, many of these datasets have suffered from the burden of being manually authored and/or annotated, affecting their size and potential to grow. To overcome this problem, we propose a novel database of stories collected from TaleMaker, an online multiplayer game that facilitates the playful co-creation of a story in order to eliminate the tedious task of authoring and annotating a dataset of stories. TaleMaker's database relational schema provides a simple story representation, in which stories are named and clearly annotated. A story is composed of a sequence of plot points, each with several slots (e.g. action, character, location) filled with sense-annotated tokens (words) associated with a WordNet synset. In this paper, we describe in detail the database schema of TaleMaker's stories repository. In addition, we suggest some of the potential applications of this repository of stories, including fostering research in fields such as story generation, narrative world generation, and word sense disambiguation.

Most storytelling games bring people together to co-create stories. However, they often require considerable creative effort and skills from all players, possibly discouraging less resourceful participants and impairing stories' quality. Moreover, most stories created within these games are usually only kept in players' minds rather than on storage, despite being a valuable and original asset, with a large potential for the narrative research community. We address these challenges with a novel mixed-initiative approach aimed at supporting a group of players to incrementally co-create a story, one sentence at a time. Our method features a hand generator that offers a unique set of tokens (words) to each player in each turn. This generator carefully combines tokens relevant to the ongoing story, to each individual player, to the group as a whole and random. We implemented this method in TaleMaker, a multiplayer online game that stimulates playful co-creation of a story. TaleMaker gives players considerable creative freedom to compose their sentences, combining a gentle structural steering with the wisdom of the group to determine the best direction for the story. The collected output of TaleMaker consists of annotated stories, with slots (e.g. action, character, location) filled with words associated with a WordNet synset. From a preliminary evaluation, players reported that TaleMaker effectively stimulated story authoring, and perceived TaleMaker-created stories of considerable quality. In addition, a first analysis of the collected tokens confirms that players mostly collected story-related tokens, rather than those randomly offered.

A narrative world (NW) is an environment which supports enacting a given story. Manually creating virtual NWs (e.g. for games and films) requires considerable creative and technical skills, in addition to a deep understanding of the story in question. Procedural generation methods, in turn, generally lack in creativity and have a hard time coping with the numerous degrees of freedom left open by a story. In contrast, mixed-initiative approaches offer a promising path to solve this tension. We propose a mixed-initiative approach assisting an NW designer in choosing plausible entities for the locations, where the story takes place. Our approach is based on a recommender method that uses common and novel associations to narrative locations, actions and entities. Our method builds upon a large dataset of co-occurrences of disambiguated terms that we retrieved from photo captions. Building on this knowledge, our solution deploys entity (un)relatedness, offers clusters of semantically and contextually related entities, and highlights novelty of recommended content, thus effectively supporting the designer’s creative task, while helping to stay consistent with the story. We demonstrate our method via an interactive prototype called roleTaleForge. Designers can obtain meaningful entity suggestions for their NWs, which enables guided exploration, while preserving creative freedom. We present an example of the interactive workflow of our method, and illustrate its usefulness.