3D Objects In Virtual Environments Research Articles

Interactive 3D Modeling with Virtual Reality

The immersive Virtual Reality (VR) environment transforms the way people learn, work, and communicate. While the traditional modeling tools such as Blender and AutoCAD are commonly used for industrial design today, handling 3D objects on a two-dimensional screen with a keyboard and mouse is very challenging. In this work, we introduce a VR modeling system named The Virtual Workshop supporting the design and manipulation of various 3D objects in virtual environments. The proposed system was developed for the Oculus Rift platform allowing a user to efficiently and precisely design 3D objects using two hands directly. The friendly system GUI supports the user to create new 3D objects from scratch using premade “basic objects” or alternatively to import an existing 3D object made in other applications. Meanwhile, the finished 3D models are stored in the standard OBJ file format and exported later for the development of 3D scenarios in other applications such as the Unity engine. From concept to design, the VR modeling system provides an open platform where the designers and the clients can better share their ideas as well as interactively refine the rendered virtual models in collaboration.

The Effects of Augmented Reality Interaction Techniques on Egocentric Distance Estimation Accuracy

Recent developments in virtual environment applications allow users to interact with three-dimensional (3D) objects in virtual environments. As interaction with 3D objects in virtual environments becomes more established, it is important to investigate user performance with such interaction techniques within a specific task. This study investigated two interaction modes, direct and indirect, depending on how the users interacted with the 3D objects, by measuring the accuracy of egocentric distance estimation in a stereoscopic environment. Fourteen participants were recruited to perform an acquisition task with both direct pointing and indirect cursor techniques at three egocentric distances and three task difficulty levels. The accuracy of the egocentric distance estimation, throughput, and task completion time were analyzed for each interaction technique. The indirect cursor technique was found to be more accurate than the direct pointing one. On the other hand, a higher throughput was observed with the direct pointing technique than with the indirect cursor technique. However, there were no significant differences in task completion time between the two interaction techniques. The results also showed accuracy to be higher at the greatest distance (150 cm from the participant) than at the closer distances of 90 cm and 120 cm. Furthermore, the difficulty of the task also significantly affected the accuracy, with accuracy lower in the highest difficulty condition than in the medium and low difficulty conditions. The findings of this study contribute to the understanding of user-interaction techniques in a stereoscopic environment. Furthermore, developers of virtual environments may refer to these findings in designing effective user interactions, especially those in which performance relies on accuracy.

Simple and effective deep hand shape and pose regression from a single depth image

Simultaneously estimating the 3D shape and pose of a hand in real time is a new and challenging computer graphics problem, which is important for animation and interactions with 3D objects in virtual environments with personalized hand shapes. CNN-based direct hand pose estimation methods are the state-of-the-art approaches, but they can only regress a 3D hand pose from a single depth image. In this study, we developed a simple and effective real-time CNN-based direct regression approach for simultaneously estimating the 3D hand shape and pose, as well as structure constraints for both egocentric and third person viewpoints by learning from the synthetic depth. In addition, we produced the first million-scale egocentric synthetic dataset called SynHandEgo, which contains egocentric depth images with accurate shape and pose annotations, as well as color segmentation of the hand parts. Our network is trained based on combined real and synthetic datasets with full supervision of the hand pose and structure constraints, and semi-supervision of the hand mesh. Our approach performed better than the state-of-the-art methods based on the SynHand5M synthetic dataset in terms of both the 3D shape and pose recovery. By learning simultaneously using real and synthetic data, we demonstrated the feasibility of hand mesh recovery from two real hand pose datasets, i.e., BigHand2.2M and NYU. Moreover, our method obtained more accurate estimates of the 3D hand poses based on the NYU dataset compared with the existing methods that output more than joint positions. The SynHandEgo dataset has been made publicly available to promote further research in the emerging domain of hand shape and pose recovery from egocentric viewpoints (https://bit.ly/2WMWM5u).

A computational model of perceptual saliency for 3D objects in virtual environments

When giving directions to the location of an object, people typically use other attractive objects as reference, that is, reference objects. With the aim to select proper reference objects, useful for locating a target object within a virtual environment (VE), a computational model to identify perceptual saliency is presented. Based on the object’s features with the major stimulus for the human visual system, three basic features of a 3D object (i.e., color, size, and shape) are individually evaluated and then combined to get a degree of saliency for each 3D object in a virtual scenario. An experiment was conducted to evaluate the extent to which the proposed measure of saliency matches with the people’s subjective perception of saliency; the results showed a good performance of this computational model.

TEKNIK INTERAKSI UNIMANUAL PUSH AND PULL MENGGUNAKAN DATA GLOVE

In a 3D user interface, interaction plays an important role in helping users to manipulate 3D objects in virtual environments. 3D devices, such as data glove and motion tracking, can potentially give users the opportunity to manipulate 3D objects in virtual reality environments such as checking, zooming, translating, rotating, merging and splitting 3D objects in a more natural and easy manner through the use of hand gestures. Hand gestures are often applied in 3D interaction techniques for converting the manipulation mode. This paper will discuss the interaction technique in a virtual environment using a combination of the Push and Pull navigation and the rotation technique. The unimanual use of these 3D interaction techniques can improve the effectiveness of users in their interaction with and manipulation of 3D objects. This study has enhanced the capability of the unimanual 3D interaction technique in terms of 3D interaction feedback in virtual environments.

Quantitative assessment of the effectiveness of using display techniques with a haptic device for manipulating 3D objects in virtual environments

Quantitative assessment is made of using two display techniques, providing two different levels of depth perception, in conjunction with a haptic device for manipulating 3D objects in virtual environments. The two display techniques are 2D display, and interactive 3D stereoscopic virtual holography display on a zSpace tablet. Experiments were conducted, by several users of different ages and computer training. The experiments involved selected pointing and manipulation tasks. The speed of performing the tasks using the two display techniques were recorded. Statistical analysis of the data is presented. As expected, the use of interactive 3D stereoscopic display resulted in faster performance of the tasks. The improvement in performance was particularly noticeable for the cases wherein the subjects needed to manipulate the haptic arm to reach objects/targets at different depths, and also when the objects/targets were occluded partially by the obstacles.

Real-Time Hand Gesture-Based Interaction with Objects in 3D Virtual Environments

This paper introduces a hand-gesture-based user interface that enables users to control virtual objects in three-dimensional (3D) virtual environments. Users are able to manipulate objects by moving, rotating, scaling, and selecting their hands in the real world. A gesturebased virtual simulation system for vehicle maintenance is developed, incorporating several object-manipulation features (such as opening a car door, sitting in a seat, replacing tires, and disassembling the engine) to evaluate the effectiveness of this protocol. Our results indicate that the proposed hand-gesture-based user interface could potentially be employed in place of a mouse or keyboard to interact with objects in 3D virtual environments.

가상 양시점화 방법을 이용한 비전기반 3차원 손 인터페이스

최근 3차원 분야의 지속적인 발전으로 인해 보다 사실적이고 실감나는 영상을 경험할 수 있게 되었고 게임과 같은 다양한 응용분야에서 활용가능하게 되었다. 특히 가상환경에서의 객체들과 상호작용하며 이를 제어하는 증강현실 분야에 많은 발전을 가져왔다. 본 연구는 한 대의 카메라를 활용한 가상 양시점화 방법을 통해 3차원 공간의 객체를 제어하는 3차원 사용자 인터페이스를 제안한다. 이를 위해 임의의 두 카메라 위치 사이의 변환 정보를 담고 있는 호모그래피(homography) 행렬을 계산하고, 한 대의 카메라에서 얻은 2차원 손 좌표, 호모그래피 행렬 그리고 카메라의 투영행렬을 이용하여 3차원 좌표의 복원을 수행한다. 이러한 방법을 통해 보다 정확하고 빠른 3차원 정보를 얻을 수 있게 된다. 이는 두 대의 카메라를 동시에 구동할 때보다 연산량이 감소하여 실시간 처리에 효과적일 수 있으며 경제적인 부담도 줄일 수 있는 장점을 가지고 있다.

Ray-Based Haptic Rendering: Force and Torque Interactions between a Line Probe and 3D Objects in Virtual Environments

Ray-Based Haptic Rendering: Force and Torque Interactions between a Line Probe and 3D Objects in Virtual Environments