An Enhanced Real-Time Shadow Rendering Technique in Outdoor Augmented Reality (original) (raw)
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Overlapping Shadow Rendering for Outdoor Augmented Reality
Computers, Materials & Continua
Realism rendering methods of outdoor augmented reality (AR) is an interesting topic. Realism items in outdoor AR need advanced impacts like shadows, sunshine, and relations between unreal items. A few realistic rendering approaches were built to overcome this issue. Several of these approaches are not dealt with real-time rendering. However, the issue remains an active research topic, especially in outdoor rendering. This paper introduces a new approach to accomplish reality real-time outdoor rendering by considering the relation between items in AR regarding shadows in any place during daylight. The proposed method includes three principal stages that cover various outdoor AR rendering challenges. First, real shadow recognition was generated considering the sun's location and the intensity of the shadow. The second step involves real shadow protection. Finally, we introduced a shadow production algorithm technique and shades through its impacts on unreal items in the AR. The selected approach's target is providing a fast shadow recognition technique without affecting the system's accuracy. It achieved an average accuracy of 95.1% and an area under the curve (AUC) of 92.5%. The outputs demonstrated that the proposed approach had enhanced the reality of outside AR rendering. The results of the proposed method outperformed other state-of-the-art rendering shadow techniques' outcomes.
Image based shadowing in real-time augmented reality
2006
Abstract—This work presents an approach to render appropriate shadows with Image Based Lighting in Augmented Reality applications. To approximate the result of environment lighting and shadowing, the system uses a dome of shadow casting light sources. The color of each shadow is determined by the area of the environment behind the casting light source. As a result it is possible that changes in the lighting conditions immidiately affect the shadow casting of virtual objects on real objects.
A real-time shadow approach for an augmented reality application using shadow volumes
2003
Abstract Shadows add a level of realism to a rendered image. Moreover, they are used as visual clues to determine spacial relationships and real-time shadows will gain importance in current real-time computer graphics applications for this reason. Twenty-five years ago, Crow published the shadow volume approach for determining shadowed regions of a scene. In this paper we present a modified real-time shadow volume algorithm that can be used in an Augmented/Mixed Reality application.
A Context-Aware Method for Authentically Simulating Outdoors Shadows for Mobile Augmented Reality
IEEE transactions on visualization and computer graphics, 2017
Visual coherence between virtual and real objects is a major issue in creating convincing augmented reality (AR) applications. To achieve this seamless integration, actual light conditions must be determined in real time to ensure that virtual objects are correctly illuminated and cast consistent shadows. In this paper, we propose a novel method to estimate daylight illumination and use this information in outdoor AR applications to render virtual objects with coherent shadows. The illumination parameters are acquired in real time from context-aware live sensor data. The method works under unprepared natural conditions. We also present a novel and rapid implementation of a state-of-the-art skylight model, from which the illumination parameters are derived. The Sun's position is calculated based on the user location and time of day, with the relative rotational differences estimated from a gyroscope, compass and accelerometer. The results illustrated that our method can generate ...
Real Time Shadow Mapping for Augmented Reality Photorealistic Rendering
Applied Sciences, 2019
In this paper, we present a solution for the photorealistic ambient light render of holograms into dynamic real scenes, in augmented reality applications. Based on Microsoft HoloLens, we achieved this result with an Image Base Lighting (IBL) approach. The real-time image capturing that has been designed is able to automatically locate and position directional lights providing the right illumination to the holograms. We also implemented a negative “shadow drawing” shader that contributes to the final photorealistic and immersive effect of holograms in real life. The main focus of this research was to achieve a superior photorealism through the combination of real-time lights placement and negative “shadow drawing” shader. The solution was evaluated in various Augmented Reality case studies, from classical ones (using Vuforia Toolkit) to innovative applications (using HoloLens).
An Overview on Base Real-Time Shadow Techniques in Virtual Environments
Abstrak Bayangan (shadow) adalah sangat bagus untuk menciptakan suasana realistis pada lingkungan virtual. Bervariasinya teknik shadow mendorong Penulis untuk mempersiapkan tinjauan pada semua teknik shadow dasar. Teknik shadow dapat dikategorikan dua kelas besar, teknik waktu-nyata dan teknik non waktu-nyata. Pada jiplakan sinar teknik non waktu-nyata, pemilihan jiplakan dan radiositas adalah sangat dikenal, dan dijelaskan secara mendalam. Radiositas diterapkan untuk menciptakan bayangan yang sangat realistis pada teknik non waktu-nyata. Karena algoritma radiositas tradisional sulit diimplementasikan, Penulis mengusulkan sesuatu yang sederhana untuk menangani hal ini. Kode pseudo yang diusulkan lebih mudah untuk dipahami dan diimplementasikan. Jiplakan sinar digunakan untuk mencegah tabrakan objek-objek bergerak. Bayangan proyeksi, banyaknya bayangan dan pemetaan bayangan digunakan untuk membuat bayangan waktu-nyata pada lingkungan virtual. Bayangan proyeksi telah digunakan untuk beberapa objek statis dan memiliki bayangan pada permukaan datar. Banyaknya bayangan digunakan untuk membuat bayangan yang akurat dengan garis tajam. Pemetaan shadow yang merupakan teknik dasar dari semua teknik terkini, direkonstruksi. Algoritma rekonstruksi ini memberikan beberapa ide baru untuk mengusulkan algoritma lain berdasarkan pemetaan bayangan. Kata kunci: banyaknya bayangan, jiplakan sinar , pemetaan bayangan, pemilihan sinar, radiositas Abstract Shadows are elegant to create a realistic scene in virtual environments. Variety types of shadow techniques encourage us to prepare an overview on all base shadow techniques. Non real-time and realtime techniques are big subdivision of shadow generation. In non real-time techniques ray tracing, ray casting and radiosity are well known and deeply described. Radiosity implemented to create very realistic shadow on non real-time scene. Although traditional radiosity algorithm is difficult to implement, we have proposed a simple one. The proposed pseudo code is easier to understand and implement. Ray tracing used to prevent of collision of movement objects. Projection shadow, shadow volume and shadow mapping are used to create real-time shadow in virtual environments. We have used projection shadow for some objects are static and have shadow on flat surface. Shadow volume used to create accurate shadow with sharp outline. Shadow mapping that is the base of most recently techniques is reconstructed. The reconstruct algorithm gives some new idea to propose another algorithm based on shadow mapping.
Improving AR using shadows arising from natural illumination distribution in video sequences
Proceedings Eighth IEEE International Conference on Computer Vision. ICCV 2001, 2001
In this paper; we propose a method for generating realistic shadows of virtual objects inserted into a real video sequence. Our aim is to improve and extend the work of [ I ] , which is based on a static camera, to the case of a video sequence. This extension consists of several procedures: calibration of a moving video camera and a graphic camera, removing false shadows occurring due to a shortcoming of the static camera approach for the estimation of an illumination distribution, and so on. The calibration of the moving camera is solved by camera self-calibration and, with it, we designed a flexible graphic world coordinate system embedding technique called "match move". We also show that the shortcoming of the previous static camera approach is overcome by using information from video sequence. Finally we present the experimental results of a real video sequence.
Proceedings of the 15th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, 2020
A realistic illumination model in Augmented Reality (AR) applications is crucial for perceiving virtual objects as real. In order to correctly blend digital content with the physical world it is necessary to measure, in real time, the illumination present in the scene surrounding the user. The paper proposes a novel solution for real-time estimation of outdoor illumination conditions, based on the video stream from the camera on handheld devices. The problem is formulated in a radiometric framework, showing how the reflected radiance from the surface maps to pixel values, and how the reflected radiance relates to surface reflectance and the illumination environment. From this we derive how to estimate the color and intensity of the sun and sky illumination, respectively, using areas in the video stream that are in direct sunlight and in shadow. The presented approach allows for rendering augmentations that adapt in real-time to dynamically changing outdoor illumination conditions.
Simulated real-time soft shadow in mixed reality using fuzzy logic
3D Research, 2013
This paper presents fuzzy logic in computer graphics to generate soft shadows in virtual environments and augmented reality. A very short overview on hard shadow generation is introduced. Shadow volume which is a conventional technique to create hard shadow is the base algorithm for our approach to show hard shadows in crisp set. A new technique with help of shadow maps for generating soft shadows using fuzzy logic is used. Fuzzy logic could change the concept of soft shadows into mathematically simple forms. Conversion of the soft shadows into fuzzy logic could change some parts of complex calculation to a simple physical based approach for increasing the speed of rendering. ARToolkit is used for geometric tracking as well as stencil buffer. A credible soft shadow is produced by splitting the wide light source into many parts.