Refine
Year of publication
Document Type
- Conference Proceeding (20)
- Article (2)
- Part of a Book (2)
Keywords
- Virtual (TV) Studio (24) (remove)
Department/institution
This article describes the possibilities and problems that occur using the SteamVR tracking 2.0 system as a camera tracking system in a virtual studio and explains an approach for implementation and calibration within a professional studio environment. The tracking system allows for cost effective deployment. Relevant application fields are also mixed reality recording and streaming of AR and VR experiences.
Acquiring human motion data from video images plays an important role in the field of computer vision. Ground truth tracking systems require markers to create high quality motion data. But in many applications it is desired to work without markers. In recent years affordable hardware for markerless tracking systems was made available at a consumer level. Efficient depth camera systems based on Time-of-Flight sensors and structured light systems have made it possible to record motion data in real time. However, the gap between the quality of marker-based and markerless systems is high. The error sources of a markerless motion tracking pipeline are discussed and a model-based filter is proposed, which adapts depending on spatial location. The proposed method is then proven to be more robust and accurate than the unfiltered data stream and can be used to visually enhance the presence of an actor within a virtual environment in live broadcast productions.
The article discusses the question of “How to convey the experience in a virtual environment to third parties?” and explains the different technical implementations which can be used for live streaming and recording of a mixed reality experience. The real-world applications of our approach include education, entertainment, e- sports, tutorials, and cinematic trailers, which can benefit from our research by finding a suitable solution for their needs. We explain and outline our Mixed Reality systems as well as discuss the experience of recorded demonstrations of different VR applications, including the need for calibrated camera lens parameters based on realtime encoder values.
Live-Video-Broadcasting mit mehreren Kameras erfordert eine Vielzahl von Fachkenntnissen. Robotersysteme ermöglichen zwar die Automatisierung von gängigen und wiederholten Tracking-Aufnahmen, diese erlauben jedoch keine kurzfristigen Anpassungen aufgrund von unvorhersehbaren Ereignissen. In diesem Beitrag wird ein modulares, automatisiertes Kamerasteuerungs- und Bildschnitt-System eingeführt, das auf grundlegenden kinematografischen Regeln basiert. Die Positionen der Akteure werden durch ein markerloses Tracking-System bereitgestellt. Darüber hinaus werden Tonpegel der Lavaliermikrofone der Akteure zur Analyse der aktuellen Szene verwendet. Ein Expertensystem ermittelt geeignete Kamerawinkel und entscheidet, wann von einer Kamera auf eine andere umgeschaltet werden soll. Eine Testproduktion wurde durchgeführt, um den entwickelten Prototyp in einem Live-Broadcast-Szenario zu beobachten und diente als Videodemonstration für eine Evaluierung.
Live video broadcasting requires a multitude of professional expertise to enable multi-camera productions. Robotic systems allow the automation of common and repeated tracking shots. However, predefined camera shots do not allow quick adjustments when required due to unpredictable events. We introduce a modular automated robotic camera control and video switch system, based on fundamental cinematographic rules. The actors' positions are provided by a markerless tracking system. In addition, sound levels of actors' lavalier microphones are used to analyse the current scene. An expert system determines appropriate camera angles and decides when to switch from one camera to another. A test production was conducted to observe the developed prototype in a live broadcast scenario and served as a video-demonstration for an evaluation.
In order to improve the interactivity between users and computers, recent technologies focus on incorporating gesture recognition into interactive systems. The aim of this article is to evaluate the effectiveness of using a Myo control armband and the Kinect 2 for recognition of gestures in order to interact with virtual objects in a weather report scenario. The Myo armband has an inertial measurement unit and is able to read electrical activity produced by skeletal muscles, which can be recognized as gestures, which are trained by machine learning. A Kinect sensor was used to build up a dataset which contains motion recordings of 8 different gestures and was also build up by a gesture training machine learning algorithm. Both input methods, the Kinect 2 and the Myo armband, were evaluated with the same interaction patterns in a user study, which allows a direct comparison and reveals benefits and limits of each technique.
Markerless talent tracking is widely used for interactions and animations within virtual environments. In a virtual (tv) studio talents could be overburden by interaction tasks because camera and text require extensive attention. We take a look into animations and inter- actions within a studio, which do not require any special attention or learning. We show the generation of an artificial shadow from a talent, which ease the keying process, where separation of real shadows from the background is a difficult task. We also demonstrate animations of footsteps and dust. Furthermore, capturing talents’ height can also be used to adjust the parameters of elements in the virtual environment, like the position and scaling of a virtual display. In addition to the talents, a rigid body was tracked as placeholder for graphics, easing the interaction tasks for a talent. Two test productions show the possibilities, which subtle animations offer. In the second production, the rendering was improved (shadows, filtering, normal maps, ...) and instead of using the rigid body to move an object (a flag), the animation was only controlled by the hand’s position.
A visual and spatial feedback system for orientation in virtual sets of virtual TV studios was developed and evaluated. It is based on a green proxy object, which moves around in the acting space by way of four transparent wires. A separate unit controls four winches and is connected to an engine, which renders the virtual set. A new developed plugin registers a virtual object’s position with the proxy object which imitates the virtual object’s movement on stage. This will allow actors to establish important eye contact with a virtual object and feel more comfortable in a virtual set. Furthermore, interaction with the virtual object and its proxy can be realised through a markerless actor tracking system. Several possible scenarios for user application were recorded and presented to experts in the broadcast industry, who evaluated the potential of SpiderFeedback in interviews and by questionnaires.
Virtual (tv) studios gain much more acceptance through improvements in computer graphics and camera tracking. Still commercial studios cannot have full interaction between actors and virtual scene because actors data are not completely digital available as well as the feedback for actors is still not sufficient. Markerless full body tracking might revolutionize virtual studio technology as it allows better interaction between real and virtual world. This article reports about using a markerless actor tracking in a virtual studio with a tracking volume of nearly 40 cubic meter enabling up to three actors within the green box. The tracking is used for resolving the occlusion between virtual objects and actors so that the Tenderer can output automatically a mask for virtual objects in the foreground in case the actor is behind. It is also used for triggering functions scripted within the Tenderer engine, which are attached to virtual objects, starting any kind of action (e.g., animation). Last but not least the system is used for controlling avatars within the virtual set. All tracking and rendering is done within a studio frame rate of 50 Hz with about 3 frames delay. The markerless actor tracking within virtual studios is evaluated by experts using an interview approach. The statistical evaluation is based on a questionnaire.
This paper presents a mobile approach of integrating tangible user feedback in today’s virtual TV studio productions. We describe a tangible multitouch planning system, enabling a single user to prepare and customize scene flow and settings. Users can view and interact with virtual objects by using a tangible user interface on a capacitive multitouch surface. In a 2D setting created TV scenes are simultaneously rendered as separate view using a production/target renderer in 3D. Thereby the user experiences a closer reproduction of a final production and set assets can be reused. Subsequently, a user can arrange scenes on a timeline while maintaining different versions/sequences. The system consists of a tablet and a workstation, which does all application processing and rendering. The tablet is just an interface connected via wireless LAN.
In this paper we introduce a system for tracking persons walking or standing on a large planar surface and for using the acquired data to easily configure position based interactions for virtual studio productions. The tracking component of the system, radarTRACK, is based on a laser scanner device capable of delivering interaction points on a large configurable plane. By using the device on the floor it is possible to use the delivered data to detect feet positions and derive the position and orientation of one or more users in real time. The second component of the system, named OscCalibrator, allows for the easy creation of multidimensional linear mappings between input and output parameters and the routing of OSC messages within a single modular design environment. We demonstrate the use of our system to flexibly create position-based interactions in a virtual studio environment.
This paper presents an approach to integrate non-visual user feedback in today's virtual tv studio productions. Since recent studies showed that systems providing vibro-tactile feedback are not sufficient for replacing the common visual feedback, we developed an audio-based solution using an in ear headphone system, enabling a talent to move, avoid and point to virtual objects in a blue or green box. The system consists of an optical head tracking system, a wireless in ear monitor system and a workstation, which performs all application and audio processing. Using head related transfer functions, the talent gets directional and distance cues. Past research showed, that generating reflections of the sounds and simulating the acoustics of the virtual room helps the listener to conceive the acoustical feedback, we included this technique as well. In a user study with 15 participants the performance of the system was evaluated.
This article presents a new approach of integrating tangible user feedback in todays virtual TV studio productions. We describe a tangible multitouch planning system, enabling multiple users to prepare and customize scene flow and settings. Users can collaboratively view and interact with virtual objects by using a tangible user interface on a shared multitouch surface. The in a 2D setting created TV scenes are simultaneously rendered on an external monitor, using a production/target renderer in 3D. Thereby the user experiences a closer reproduction of a final production. Subsequently, users are able to join together the scenes into one complex plot. Within the developing process, a video prototype of the system shows the user interaction and enables early reviews and evaluations. The requirement analysis is based on expert interviews.
In this paper we describe a prototypical system for live musical performance in a virtual studio environment. The performer stands in front of the studio camera and interacts with an infrared-laser-based multi-touch device. The final TV image shows the performer interacting with a virtual screen which is augmented in front of herself. To overcome the problem of the performer not seeing this virtual screen in reality, we use a special hexagonal grid to facilitate the performer's awareness of this novel Theremin-like virtual musical instrument.
Shadows in computer graphics are an important rendering aspect for spatial objects. For realtime computer applications such as games, it is essential to represent shadows as accurate as possible. Also, various tv stations work with virtual studio systems instead of real studio sets. Especially for those systems, a realistic impression of the rendered and mixed scene is important. One challenge, hence, is the creation of a natural shadow impression. This paper presents the results of an empirical study to compare the performance and quality of different shadow mapping methods. For this test, a prototype studio renderer was developed. A percentage closer filter (pcf) with a number of specific resolutions is used to minimize the aliasing issue. More advanced algorithms which generate smooth shadows like the percentage closer soft shadow (pcss) method as well as the variance shadow maps (vsm) method are analysed. Different open source apis are used to develop the virtual studio renderer, giving the benefit of permanent enhancement. The Ogre 3D graphic engine is used to implement the rendering system, benefiting from various functions and plugins. The transmission of the tracking data is accomplished with the vrpn server/client and the Intersense api. The different shadow algorithms are compared in a virtual studio environment which also casts real shadows and thus gives a chance for a direct comparison throughout the empirical user study. The performance is measured in frames per secon
For this study, an experimental vibrotactile feedback system was developed to help actors with the task of moving their arm to a certain place in a virtual tv studio under live conditions. Our intention is to improve interaction with virtual objects in a virtual set, which are usually not directly visible to the actor, but only on distant displays. Vibrotactile feedback might improve the appearance on tv because an actor is able to look in any desired direction (camera or virtual object) or to read text on a teleprompter while interacting with a virtual object. Visual feedback in a virtual studio lacks spatial relation to the actor, which impedes the adjustment of the desired interaction. The five tactors of the implemented system which are mounted on the tracked arm give additional information like collision, navigation and activation. The user study for the developed system shows that the duration for reaching a certain target is much longer in case no visual feedback is given, but the accuracy is similar. In this study, subjects reported that an activation signal indicating the arrival at the target of a drag & drop task was helpful. In this paper, we discuss the problems we encountered while developing such a vibrotactile display. Keeping these pitfalls in mind could lead to better feedback systems for actors in virtual studio environments.
Actors in virtual studio productions are faced with the challenge that they have to interact with invisible virtual objects because these elements are rendered separately and combined with the real image later in the production process. Virtual sets typically use static virtual elements or animated objects with predefined behavior so that actors can practice their performance and errors can be corrected in the post production. With the demand for inexpensive live recording and interactive TV productions, virtual objects will be dynamically rendered at arbitrary positions that cannot be predicted by the actor. Perceptive aids have to be employed to support a natural interaction with these objects. In our work we study the effect of haptic feedback for a simple form of interaction. Actors are equipped with a custom built haptic belt and get vibrotactile feedback during a small navigational task (path following). We present a prototype of a wireless vibrotactile feedback device and a small framework for evaluating haptic feedback in a virtual set environment. Results from an initial pilot study indicate that vibrotactile feedback is a suitable non-visual aid for interaction that is at least comparable to audio-visual alternatives used in virtual set productions.
Two high dynamic range HDR environments maps based on video streams from fish-eye lens cameras are used for generating virtual lights in a virtual set renderer. The task of realistic virtual light setup of scenes using captured environment maps might be eased as well as visual quality improves. We discuss the light setting problem for virtual studio tv productions which have mixed scenes of real objects, actors, virtual objects and virtual backgrounds. Benefits of hdr interactive light control are that the real light in the studio does not have to be remodeled and the artistic impression by using the light in the studio is also captured. An analysis of system requirements identifies technical challenges. We discuss the properties of a prototype system including test production.
High dynamic range environments maps based on still images or video streams are used for computer animation or interactive systems. The task of realistic light setup of scenes using captured environment maps might be eased as well as the visual quality improves. In this article, we discuss the light setting problem for virtual studio (tv) layout and system become more complex to handle this new feature of studio light capturing. The analysis of system requirements identifies the technical challenges.
Virtual set environments for broadcasting become more sophisticated as well as the visual quality improves. Realtime interaction and production-specific visualization implemented through plugin mechanism enhance the existing systems like the 3DK. This work presents the integration of the Intersense IS-900 SCT camera tracking and 3D interaction into the 3DK virtual studio environment. The main goal of this work is the design of a virtual studio environment for post productions, which includes video output as well as media streaming formats such as MPEG-4. The systems allows high quality offline rendering during post production and 3D interaction by the moderator during the recording.
Virtual set environments for broadcasting become more sophisticated as well as the visual quality improves. Realtime interaction and production-specific visualization implemented through plugin mechanism enhance the existing systems like the virtual studio software 3DK. This work presents an algorithm which can dynamically manage textures of high resolution by prefetching them depending on their requirement in memory and map them on a procedural mesh in realtime. The main goal application of this work is the virtual representation of a flight over a landscape as part of weather reports in virtual studios and the interaction by the moderator.
Virtual sets have evolved from computer-generated, prerendered 2D backgrounds to realtime, responsive 3D computer graphics and are nowadays standard repertoire of broadcasting divisions. The graphics, which are combined with real video feed becoming moresophisticated, real looking and more responsive. We will look at the recent developments and suggest further developments like integration of spatial audio into the studio production and generating interactive media streams. Educational institutes recognize the demands of the rising media industry and established new courses on media technology like the Duesseldorf University of Applied Sciences.