Environments and System Types of Virtual Reality Technology in STEM: a Survey <s> 1) Navigation: <s> Grabbing and manipulating virtual objects is an important user interaction for immersive virtual environments. We present implementations and discussion of six techniques which allow manipulation of remote objects. A user study of these techniques was performed which revealed their characteristics and deficiencies, and led to the development of a new class of techniques. These hybrid techniques provide distinct advantages in terms of ease of use and efficiency because they consider the tasks of grabbing and manipulation separately. CR Categories and Subject Descriptors: 1.3.7 [Computer Graphics] :Three-Dimensional Graphics and Realism - Virtual Reality; 1.3.6 [Computer Graphics]:Methodology and Techniques - Interaction Techniques. <s> BIB001 </s> Environments and System Types of Virtual Reality Technology in STEM: a Survey <s> 1) Navigation: <s> Cognitive maps are mental models of the relative locations and attribute phenomena of spatial environments. The ability to form cognitive maps is one of the innate gifts of nature. An absence of this ability can have crippling effect, for example, on the visually impaired. The sense of touch becomes the primary source of forming cognitive maps for the visually impaired. Once formed, cognitive maps provide precise mapping of the physical world so that a visually impaired individual can successfully navigate with minimal assistance. However, traditional mobility training is time consuming, and it is very difficult for the blind to express or revisit the cognitive maps formed after a training session is over. The proposed haptic environment will allow the visually impaired individual to express cognitive maps as 3D surface maps, with two PHANToM force-feedback devices guiding them. The 3D representation can be finetuned by the care-giver, and then felt again by the visually impaired in order to form precise cognitive maps. In addition to voice commentary, a library of pre-existing shapes familiar to the blind will provide orientation and proprioceptive haptic-cues during navigation. A graphical display of cognitive maps will provide feedback to the care-giver or trainer. As the haptic environment can be easily stored and retrieved, the MoVE system will also encourage navigation by the blind at their own convenience, and with family members. <s> BIB002 </s> Environments and System Types of Virtual Reality Technology in STEM: a Survey <s> 1) Navigation: <s> We report a series of experiments conducted to investigate the effects of travel technique on information gathering and cognition in complex virtual environments. In the first experiment, participants completed a non-branching multilevel 3D maze at their own pace using either real walking or one of two virtual travel techniques. In the second experiment, we constructed a real-world maze with branching pathways and modeled an identical virtual environment. Participants explored either the real or virtual maze for a predetermined amount of time using real walking or a virtual travel technique. Our results across experiments suggest that for complex environments requiring a large number of turns, virtual travel is an acceptable substitute for real walking if the goal of the application involves learning or reasoning based on information presented in the virtual world. However, for applications that require fast, efficient navigation or travel that closely resembles real-world behavior, real walking has advantages over common joystick-based virtual travel techniques. <s> BIB003 </s> Environments and System Types of Virtual Reality Technology in STEM: a Survey <s> 1) Navigation: <s> Virtual environments are more and more used for educational and training purposes. In order to design virtual environments for these applications in particular, it is very important to get a deep understanding of the relevant design features supporting the user's process of learning and comprehension. Relevance and implementation of these features as well as the benefits of virtual learning environments over traditional educational approaches in general are rarely explored. Focusing on modes of interaction in this work, we examined the effect of different motion types on the knowledge acquisition of users in various virtual environments. For our study we chose a simple memorization task as approximation of low cognitive knowledge acquirement. We hypothesized motion types and immersion levels influence memorization performance in virtual environments. The memorization task was conducted in two virtual environments with different levels of immersion: A high-immersive Cave Automatic Virtual Environment (CAVE) and a low-immersive desktop virtual environment. Two motion types in virtual environments were explored: Physical and virtual walking. In the CAVE physical walking was implemented by using motion capturing and virtual walking was realized using a joystick-like input device. The results indicate neither motion types nor immersion levels in virtual environments affect memorization performance significantly. <s> BIB004 </s> Environments and System Types of Virtual Reality Technology in STEM: a Survey <s> 1) Navigation: <s> The purpose of this study was to examine the effect of navigation mode (passive versus active) on the virtual/real transfer of spatial learning, according to viewpoint displacement (ground: 1m 75 versus aerial: 4m) and as a function of the recall tasks used. We hypothesize that active navigation during learning can enhance performances when route strategy is favored by egocentric match between learning (ground-level viewpoint) and recall (egocentric frame-based tasks). Sixty-four subjects (32 men and 32 women) participated in the experiment. Spatial learning consisted of route learning in a virtual district (four conditions: passive/ground, passive/aerial, active/ground, or active/aerial), evaluated by three tasks: wayfinding, sketch-mapping, and picture-sorting. In the wayfinding task, subjects who were assigned the ground-level viewpoint in the virtual environment (VE) performed better than those with the aerial-level viewpoint, especially in combination with active navigation. In the sketch-mapping task, aerial-level learning in the VE resulted in better performance than the ground-level condition, while active navigation was only beneficial in the ground-level condition. The best performance in the picture-sorting task was obtained with the ground-level viewpoint, especially with active navigation. This study confirmed the expected results that the benefit of active navigation was linked with egocentric frame-based situations. <s> BIB005
It is the essential tool for the usability in the VR. It is the main part to form virtual environments  . The navigation task allows the user to move from one place to another one in the VR. It provides the user the guidance about the destination and place of 3D objects  ,  . 2) Immersion: It allows the user the feel of sense and presence as in the real world. The feeling of immersion could bring by the 3D objects, by the interaction with it, and by the navigation through the VR environment. 3) Interaction: It is done between the user and the objects in the virtual world to give the user the feeling of presence and the feel of acting within the reality environment in real time  . In the VR, the main component which leads to the other components is the navigation. The navigation behaviors in VR allow the user to interact and manipulate the 3D objects by input/output devices. The devices in a semi-immersive (developed desktop VR) are like mouse, keyboard, 3D mouse, and joystick. These allow the navigation in VR to improve the spatial presence (cognitive map) of the user  ,  . The cognitive map means the mental images. The first term of the cognitive map used by Tolman to mean the cognitive map is the description of the mental representation of spatial information and it is the internal (mentally) representation of spatial environments BIB002 . The cognitive map used to solve the spatial problems (visualization) such that we need in our research by the navigation as many types of research conclude it BIB004 , BIB005 . The interaction in VR has three types of tasks. The tasks are navigation, manipulation (selecting), and system control  . The navigation task as we know is moving from one point to another among 3D objects in VR. It allows the movement between many different locations in the virtual world. The navigation task consists of two components that are  , BIB003 ,  : 1) Travel (the motor component): means the movement from one particular location in virtual space to another one. 2) Wayfinding (the cognitive component): means the process of connection to find the paths in VR to travel through it. The wayfinding and travel build up and improve the cognitive map (spatial visualization). Moreover, the navigation task classified into three categories that are maneuvering, search tasks and exploration allows the user to navigate (move) and travel from one viewpoint in VR to another point of view. The manipulation (selecting) is selecting a specific object in VR and by choosing the user can start the manipulations such as rotate, zoom in, zoom out, and flying over the objects. Selecting allows the user to apply a specific command for the selected object and to change the attributes of the selected object. The third component is system control. It is the changing of the state of a system or mode of interaction  ,  . The navigation, cognitive map, and wayfinding have a relationship with each other. The navigation and wayfinding improve the cognitive map (spatial skill) to solve the spatial problems. The navigation and wayfinding are terms used interchangeably to refer to "a person's abilities, both cognitive and behavioral, to reach spatial destinations"  . The wayfinding is one component of the navigation task. Wayfinding does not mean the travel over the objects, but it means the tactical part of manipulation to allow the user of VR to apply the third part of VR environment in our model which we will build the system according to the framework of cognitive theory by Daghestani. The motion refers to the term of travel that allows users to move the objects in the virtual world BIB001 -  . So, the cognitive map by navigation and wayfinding helps to improve the visualization ability and skill in the VR to visualize the paths, locations, detail of objects and its features. The cognitive map allows the person to remember and visualize the structure of objects and its locations in the VR  . The navigation is the result of exploration, manipulation and searching in the virtual environments. According to the navigation, the spatial awareness (spatial visualization) is improved  . The navigation in VR and specifically in desktop VR (semi-immersive) can be done by the six degrees of freedom (6DoF). The navigation with 6DoF as shown in Fig. 13 support the spatial reasoning by allowing students to manipulate a model to examine its parts, scan its features, display many objects that make one solid model and compare these objects, define the spatial styling of an object  . The six DOF means can see the object from six sides that are: up-down; left-right; forward-back; pitch; yaw; and roll, and allow users to navigate and manipulate the objects in the VR environments. www.ijacsa.thesai.org 