# Exploring the Effect of Virtual Environments on Passive
## 1 Introduction  
Recently, virtual reality (VR) has received significant attention as a key technology for education, training, and entertainment, in that it may prove to be a more effective method of interaction, especially as the experience of users in immersive environments improves [1, 2]. This technology can create various situations with useful information, allow for participant interaction, and provide the sense of being in the immersive virtual environment [3]. To increase immersion in the participant's virtual environment, recent studies have been conducted on haptic interaction based on virtual objects [4]. For example, it is necessary to apply interaction methods to naturally manipulate an object using haptic feedback from virtual objects. Thus, although the user's virtual environment is different compared to the real one, the virtual environment should be configured to provide the user with a sense of consistency between the two environments [5]. However, technical difficulties must be resolved to match physical configurations with different virtual spaces to enhance the user's presence. Furthermore, virtual reality systems need to be built in an effective way while maintaining a level of presence, called the \"minimum cue\" [6]. In this line of thinking, this paper presents the effect of haptic perception with respect to the transformation (e.g., position, orientation, and scale) of a virtual object according to different physical conditions. Passive haptic is an interaction technique in VR that uses physical objects to provide feedback to the participant through shape, thus substantiating their virtual counterparts [7]. For instance, when a user interacts with a virtual object in a passive haptic scenario, the participant recognizes when the size of the virtual object differs from the size of the corresponding real object. In this situation, the feeling of being in thevirtual environment is quickly broken; as a result, the participant's sense of presence is lowered [3]. In general, it is difficult to use several physical objects that correspond to virtual objects to realize passive haptic scenarios in order to experience a complex virtual environment. Thus, in our study, we focused on the effect of passive haptic on users' perception through different transformation conditions in immersive virtual environments. Then, we tried to measure the level of feeling through an \"available cue\" for physical objects. In other words, we found the degree to which different virtual and real objects can be implemented in an immersive virtual environment. Our method is expected to be able to create and present guidelines for the creation of immersive virtual reality content. Figure 1 shows an example of a typical interaction situation using passive haptic with an immersive virtual environment. The user wearing the HMD sits in the chair, manipulates the physical object for passive haptic cues, and interacts with it. In terms of the user's perception, given the availability of immersive environments, it has become possible for the user to experience virtual objects as if they were real [8]. Accordingly, VR content can create the feeling of being in a virtual environment where the virtual object is appropriately transformed to increase the level of presence. Recently, there have been a few attempts to overcome the limitation of conflicting information coming from the physical object and from the virtual one, such as situations of different positions, size, and shape [9]. Therefore, it is necessary to resolve differences between real and virtual objects, and the participant should be able to recognize the same object with a perceived coherence. The results indicated that the method helped to improve the sense of presence while dynamically aligning the physical and virtual objects, and it allowed the participant to experience correct and natural interactions in the virtual environment.