Abstract
This paper presents a solution for geometric manipulation in procedural modeling as an Application Programming Interface (API). This approach intends to enable a more powerful control over the geometric entities by performing selections based on their attributes, similar to picking features in graphical interfaces. This is achieved through the definition of a topological structure, which features a set of properties, such as scope, spatial localization and semantic information. The applicable modeling operations allow a more customized control, as well as successive tracking, which induce a greater, faster and more intuitive approach for geometry generation. This approach still constitutes ongoing work, but has already been successfully applied for the generation of large virtual urban environments.

Abstract
Objectives Research into the effectiveness of mindfulness-based programs (MBPs) in school settings has grown substantially. However, studies in the field are still scarce, present methodological limitations, and fail to examine how children's characteristics influence MBPs' effects. The twofold aim of this study was to analyze the effectiveness of an MBP on children's attention and emotional regulation, writing performance, and school grades, and to evaluate the moderating role of baseline scores, age, gender, and socioeconomic status. Methods Fifty-seven third graders received the MBP (n = 28) or a health-based program (n = 29), which is the active control group, for 8 weeks. In each week, both programs were composed of two 30-min sessions delivered by psychologists and three 5-min sessions delivered by teachers. Before and after the implementation of the programs, we assessed teacher-rated children's attention and emotional regulation, performance-based attention networks (alerting, orienting, and conflict monitoring), writing performance (handwriting fluency, spelling, and text quality), and school grades in Portuguese, Mathematics, and Social Studies. Results Compared to the control group, after the program, the mindfulness group displayed higher teacher-rated attention and emotional regulation, as well as better Portuguese, Mathematics, and Social Studies grades. Emotional regulation and alerting baseline scores as well as age were found to moderate the MBP's effects. Conclusions These findings provide preliminary evidence on the effectiveness of a MBP on children's behavior and school grades. This means that students may benefit from the integration of mindfulness practices into the educational setting as a complement to the school curriculum.

Abstract
Content generation is a heavy task in virtual worlds design. Procedural content generation techniques aim to agile this process by automating the 3D modelling with some degree of parametrisation. The novelty of this work is the procedural generation of the marine alga (Asparagopsis armata), taking into consideration the underwater environmental factors. The depth and the occlusion were the two parameters in this study to simulate how the alga growth is influenced by the environment where the alga grows. Starting by building a prototype to explore different L-systems categories to model the alga, the stochastic L-systems with parametric features were selected to generate different alga plasticities. Qualitative methods were used to evaluate the designed grammar and alga's animation results by comparing videos and images of the Asparagopsis armata with the computer-generated versions. © 2022 University of West Bohemia. All rights reserved.

Abstract
In Virtual Reality, feedback is usually provided through the handheld controllers. However, it is often limited to vibrotactile feedback. Some research has been done on property changing haptics, which can adapt to some characteristics of the virtual object being interacted with, thus being able to represent distinct objects. However, these are mostly focused on shape or texture and are mostly grounded devices. In this work, we propose a device that can change the material exposed to the user and is simultaneously untethered and ungrounded. Results from a user evaluation with 21 participants showed that our device can successfully convey different types of materials and that the same physical material can be used to make the user perceive different virtual materials.

Abstract
Editing 360 degrees videos remains a challenge in the content creation process of immersive experiences, video editing tools are primarily presented as 2D desktop GUI applications. These interfaces provide limited capabilities for previewing content in a virtual reality (VR) headset or for manipulating the spherical video directly in an intuitive manner. As a result, editors must alternate between editing on the desktop and previewing in the headset, which may be tedious and interrupts the creative process. In this work, we present the conceptualization, implementation, and evaluation of an immersive 3D editor, built as an extension of an existing 2D editor, which allows for 360 degrees editing directly using a VR headset with controllers. The editor provides the main functionalities to create 360 degrees experiences augmented with visual annotations to provide information or guide users' attention during the viewing experience. The immersive editor was evaluated through a user study to assess its usability and intuitiveness. Participants performed several tasks in both the existing 2D editor and the developed immersive editor, and provided feedback on their experience. Results indicate that performing editing tasks in the immersive editor felt overall easier and more intuitive, while also identifying potential changes and improvements to be addressed as future work.

Abstract
Virtual Reality (VR) can be an excellent platform for collaborative work. However, standing in VR and gesturing in midair can be physically exhausting. We introduce RepliCo, a collaborative DeskVR approach focused on communication in the context of 3D content reviewing. Using an interactive surface and the world-in-miniature metaphor, it addresses common challenges in virtual collaboration, such as spatially referencing points of interest and user awareness. We conducted a user evaluation with 20 participants to assess the viability of our approach in both a large and a small environment. Results revealed that RepliCo efficiently allowed users to share points of interest in a user-friendly and physically undemanding manner. Although the larger model was identified as requiring more effort, there were few significant differences in task completion times, highlighting RepliCo's versatility.