Ramón Mollá

A comparative study using an autostereoscopic display with augmented and virtual reality

Advances in display devices are facilitating the integration of stereoscopic visualisation in our daily lives. However, autostereoscopic visualisation has not been extensively exploited. In this paper, we present a system that combines augmented reality (AR) and autostereoscopic visualisation. We also present the first study that compares different aspects using an autostereoscopic display with AR and virtual reality (VR), in which 39 children from 8 to 10 years old participated. In our study, no statistically significant differences were found between AR and VR. However, the scores were very high in nearly all of the questions, and the children also scored the AR version higher in all cases. Moreover, the children explicitly preferred the AR version (81%). For the AR version, a strong and significant correlation was found between the use of the autostereoscopic screen in games and seeing the virtual object on the marker. For the VR version, two strong and significant correlations were found. The first correlation was between the ease of play and the use of the rotatory controller. The second correlation was between depth perception and the game global score. Therefore, the combinations of AR and VR with autostereoscopic visualisation are possibilities for developing edutainment systems for children.

Exploring peripheral LOD change detections during interactive gaming tasks

Computer games require players to interact with scenes while performing various tasks. In this paper an experimental game framework was developed to measure players perception to level of detail (LOD) changes in 3D models (for example a bunny), as shown in Figure 1. These models were unrelated to the task assigned to the player and located away from the area in which the task was being accomplished. An interactive task, such as a point and shoot game, triggers a top-down vision process. Performing a specific task can result in inattentional blindness (IB) for the player, which is the phenomenon of not being able to perceive things that are in plain sight. IB can allow for substantial simplifications of the objects in the scene unrelated to the task at hand. In this paper five experiments were conducted exploring peripheral LOD change detections during an interactive gaming task. In three of the five experiments different level of awareness for the same task were tested and it was found that only participants being fully aware of the 3D LOD changes were able to detect about 15% of them during the game. In the other two experiments and with the players fully aware of the LOD changes, the distance at which they were able to detect each change of resolution was measured, with different number of LOD levels used in both experiments.

Advanced displays and natural user interfaces to support learning

ABSTRACT Advanced displays and natural user interfaces (NUI) are a very suitable combination for developing systems to provide an enhanced and richer user experience. This combination can be appropriate in several fields and has not been extensively exploited. One of the fields that this combination is especially suitable for is education. Nowadays, children are growing up playing with computer games, using mobile devices, and other technological devices. New learning methods that use these new technologies can help in the learning process. In this paper, two new methods that use advanced displays and NUI for learning about a period of history are presented. One of the methods is an autostereoscopic system that lets children see themselves as a background in the game and renders the elements in 3D without the need for special glasses; the second method is a frontal projection system that projects the image on a table in 2D and works similarly to a touch table. The Microsoft Kinect© is used in both systems for the interaction. A comparative study to check different aspects was carried out. A total of 128 children from 7 to 11 years old participated in the study. From the results, we observed that the different characteristics of the systems did not influence the childrens acquired knowledge, engagement, or satisfaction. There were statistically significant differences for depth perception and presence in which the autostereoscopic system was scored higher. However, of the two systems, the children considered the frontal projection to be easier to use. We would like to highlight that the scores for the two systems and for all the questions were very high. These results suggest that games of this kind (advanced displays and NUI) could be appropriate educational games and that autostereoscopy is a technology to exploit in their development.

From continuous to discrete games

Computer games follow a scheme of continuous simulation, coupling the rendering phase and the simulation phase. That way of operation has disadvantages that can be avoided using a discrete event simulator as a game kernel. This paper proposes to integrate a discrete event simulator (DESK) to manage the videogames events. The videogame kernel used is Fly3D. The new kernel is called DFlySD. It allows a discrete event simulation scheme and the rendering and simulation phase independence. The integration objective has been to maintain the FlySD main structure and functionality, changing only the events management. The videogames objects behavior and interconnection is modeled by message passing. Maintaining the videogame quality, the videogames created using DFlySD allow reducing the computer power used to execute it. That allows to execute the videogame in computers with less computing power or to improve the game quality

Parallel fixed point digital differential analyzer

Two main serial algorithms to scan convert straight lines have been proposed: Bresenham and Digital Differential Analyzer. The Bresenham algorithm has became a standard because of integer arithmetic. Many theoretical solutions have been proposed to parallelize Bresenham algorithm but its implementation is difficult. So most parallelizations take advantage of repeated patterns, massive parallel computers and so on. Sequential Digital Differential Analyzer shows better peformance than Bresenham if fixed point arithmetic is used. This algorithm can be pipe lined and parallelized. It is easily hardware implemented and scalable. Hardware cost is linear with speed up. Utilization is nearly 100% and hardware waste is low.

Videogames decoupled discrete event simulation

Real-time graphic applications and specifically videogames, follow a paradigm of continuous simulation that couples the simulation phase and the rendering phase. This paradigm can be inefficient (inadequate computer power distribution) or it can produce incorrect simulations (disordered events execution or events lost). The use of a decoupled discrete paradigm avoids incorrect simulations, besides it improves the simulation quality and efficiency. GDESK is a discrete decoupled simulation kernel that can be integrated in any videogame or real-time graphic application to change its simulation paradigm to a discrete decoupled one. Once GDESK is integrated inside the videogame, it becomes into a set of objects being communicated by messages. Messages are modeled using discrete events. GDESK manages the messages exchange process (events synchronization, messages sending and reception process, etc.).

Making Discrete Games

Current computer games follow a scheme of continuous simulation, coupling the rendering phase and the simulation phase. That way of operation has disadvantages that can be avoided using a discrete event simulator as a game kernel. Discrete simulation supports also continuous simulation and allows rendering and simulation phase independence. The videogames objects behavior and interconnection is modeled by message passing. Discrete games require lower computer power while maintaining the videogame quality. This means that videogame may be run in slower computers or the game quality may be improved (artificial intelligence, collision detection accuracy, increase realism).

The stair algorithm

Abstract This algorithm draws straight lines on discrete devices as if they were staircases. It determines the fractional average length of each step, and it fills the pixels along every scanline intersected by the line to be drawn. This algorithm supports fractional line ends, and it uses internal 32-bit fixed-point arithmetic; 16 bits for the integer and 16 bits for the decimal part.

Virtual Environment Mapping Module to Manage Intelligent Flight in an Indoor Drone

This paper presents a Virtual Environment Mapping (VEM) module assembled in an indoor drone in order to be used by creative industries. This module is in charge of allowing users to capture the environment where the final recording will take place. Having a virtual representation of the environment allows both the photography director and the director to test different camera trajectories, points of view, speeds and camera configuration without the need to be physically in the recording set. The digitization of the scene will be performed with a 3D camera on-board of the drone. This paper discusses the overall VEM architecture, taking into account the requirements it has to fulfil. It will also present a working demo of the system, with the communication infrastructure in place and with a proof of concept of the main components of system.

Intelligent Flight in Indoor Drones

Currently, drones are one of the most complex control systems. This control covers from the control of the stability of the drone, to the automatic control of the navigation in complex environments. In the case of indoor drones, technological challenges are specific. This paper presents an intelligent control architecture for indoor drones where security is the main axis of the system design. So, a definition of different navigation modes based on security is proposed. The drone must have different navigation modes: manual, reactive, deliberative and intelligent. For indoor navigation it is necessary to know the position of the drone, therefore the system must have a location mode similar to GPS, but that provides better accuracy. For deliberative and intelligent modes, the system must have a map of the environment, as well as a control system that sends the navigation orders to the drone.