The front of the unit houses many of the sensors and related hardware, including the processors, cameras and projection lenses. The visor is tinted; enclosed in the visor piece is a pair of transparent combiner lenses, in which the projected images are displayed in the lower half. The HoloLens must be calibrated to the interpupillary distance (IPD), or accustomed vision of the user.
In combination with bitnamic CONNECT, also available as an app for both HoloLens models, maintenance processes can be significantly accelerated and complex problems on machines can be quickly resolved under expert guidance. How this works in practice, you can read in our article Maintenance and service with Remote Maintenance and Microsoft HoloLens.
Using a few straightforward variables and scripts, any Windows Universal app can be upgraded to support Windows Holographic use. Fundamentally that means setting a default virtual position for the holograms in the room, and requesting current head position from the HoloLens hardware.
Holograms eliminate the need for wood and plastic models. In the next video, an architect puts a model into the space between existing buildings and reviews holograms of the entire block on a meeting room table.
Ductworks and pipes could be visualized before assembly to overview the entire scope and check for collisions. Elements can be layered and reviewed by separate layers, each visualized in a different, distinct color.
One way to incorporate external tracking systems into 3D-AR applications is to affix hardware to the headset to simultaneously track the headset and surgical tools or other objects that will be visualized in the headset. The primary challenge to this approach is that accurate hologram visualization depends on the position and orientation of the headset view origin, which cannot be precisely determined by physically examining the headset. When tracking hardware is attached to the headset, the coordinates of the tracking markers, M, are related to the coordinates of the headset view origin, H, by a rigid transformation with rotation R and translation t:
Shortly thereafter, university artists began working with medical school faculty to create anatomically accurate visuals in 3D. Developers quickly learned the ins-and-outs of how the device worked. These components are not merely hardware and software; they are an entrée to imagining new paradigms for learning and collaboration. Students are now able to explore the wonders of human anatomy via a dynamic journey through the body. This digital model provides an opportunity for robust simulations of living tissues, including physiological and biochemical processes. It will enable them to extract or expand particular organs or systems, view the body from a range of angles, and enable exploration without the fear of making a mistake. As IC Executive Director Erin Henninger explains, the programs are designed "to shift from centuries of dissection and 2D illustrations to a 3D systems-level view, at true human scale."
AR and especially MR systems are poised to become the next computing platform, replacing ailing desktop and laptop hardware, and now even the aging tablet computing hardware. Such systems are mostly untethered for most of them (see HoloLens 1) and require high-end optics for the display engine, combiner optics, and sensors (depth scanner camera, head-tracking cameras to provide 6DOF, accurate eye trackers, and gesture sensors). These are currently the most demanding headsets in terms of hardware, especially optical hardware, and are the basis of this review paper.
Next, we point out the differences between the various coupler elements and waveguide combiner architecture used in such products. We will also review new coupler technologies that have not yet been applied to enterprise or consumer products. While the basic 2D EPE expansion technique might be straightforward, we will discuss alternative techniques that can allow a larger FOV to be processed by both in-coupler and out-couplers (either as surface gratings or volume holograms). Finally, we will review the mastering and mass replication techniques of such waveguide combiners to allow scaling and consumer cost levels.
Increasing the index swing can optimize the efficiency and/or angular and spectral bandwidths of the hologram. However, this is difficult to achieve with most available materials and might also produce parasitic effects such as haze. Increasing the thickness of the hologram is another option, especially when sharp angular or spectral bandwidths are desired, such as in telecom spectral and angular filters. This is not the case for an AR combiner, where both spectral and bandwidths need to be wide (to process a wide FOV over a wide spectral band such as LEDs). However, a thicker hologram layer also allows for phase multiplexing over many different holograms, one on top of another, allowing for multiple Bragg conditions to operate in concert to build a wide synthetic spectral and/or angular bandwidth, as modeled by the Kogelnik theory . This is the technique used by Akonia, Inc. (a US start-up in Colorado, formerly InPhase Inc., which was originally funded and focused to produce high-density holographic page data-storage media, ruled by the same basic holographic phase-multiplexing principles ).
The coming years will be an exciting time for MR hardware. A full ecosystem to allow for commodity mass production and lower costs of waveguide grating combiners is growing worldwide, comprising high-index ultraflat glass wafer manufacturers, high-index resin material developers, process equipment developers, NIL equipment developers, and also dedicated software design tools developers allow finally this technology to emerge as a viable option for the upcoming consumer MR and smart glass market.
When first putting on the headset, the system performs an eye-tracking calibration. The system produces a series of firework-like holograms in the periphery of the field of view that the user follows with their eyes. The process takes a short time to complete and requires no additional effort on the part of the wearer.
The efficiency of software also extends to the hardware. While the dynamism of spatial sound is best maintained and experienced over headphones, the HoloLens team needed to steer clear of any occlusions to keep the mixed reality effects intact. "We quickly realized that the user would like to hear the environment around them in addition to the sound from the holograms," says Håkon Strande, senior program manager at Microsoft. "So we needed something that was outside the ear but close enough to make sure the sound reached the ear at a certain level of loudness."
Augmented reality (AR), the extension of the real physical world with holographic objects provides numerous ways to influence how people perceive and interact with geographic space. Such holographic elements may for example improve orientation, navigation, and the mental representations of space generated through interaction with the environment. As AR hardware is still in an early development stage, scientific investigations of the effects of holographic elements on spatial knowledge and perception are fundamental for the development of user-oriented AR applications. However, accurate and replicable positioning of holograms in real world space, a highly relevant precondition for standardized scientific experiments on spatial cognition, is still an issue to be resolved. In this paper, we specify technical causes for this limitation. Subsequently, we describe the development of a Unity-based AR interface capable of adding, selecting, placing and removing holograms. The capability to quickly reposition holograms compensates for the lack of hologram stability and enables the implementation of AR-based geospatial experiments and applications. To facilitate the implementation of other task-oriented AR interfaces, code examples are provided and commented.
As both the Microsoft HoloLens and the HTC Vive Pro are capable of tracking head movements, they make it possible to create an impression of permanent presence of holographic geospatial objects. Even if the user walks around in a defined area, commonly indoor area, holograms remain and adopt to the user location and viewing perspective. This permanent and adaptable holographic projection may lead to visualization approaches that bring additional advantages for the cognitive processing of the geospatial area experienced.
The mode of user input is determined by the used AR hardware. The HTC Vive Pro uses hand controllers that send a ray similar to a laser pointer. The user can use this ray to aim at a Button of the holographic interface and to interact with it by clicking on a trigger button on the hand controller (see Fig. 5). The Microsoft HoloLens uses an invisible ray that is casted forward from the front of the headset. When the invisible ray hits a hologram, a circular cursor is displayed at the hit point. To aim at a Button, the user needs to turn the headset towards the Button. In other words, the Button needs to be in the center of the field of view. The user can then interact with it using the air tap gesture, which includes lifting and then bending the index finger (see Fig. 5).
Furthermore, we illustrated which technical characteristics of current AR devices are in conflict with the identified requirements. Especially the stability of holograms was argued to be affected by tracking issues of current AR headsets. As a workaround, we described the development process of an AR interface capable of adding, removing and placing holograms precisely in real world space. This interfaces allows to perform standardized scientific experiments using AR hardware by correcting false hologram positions manually. To reduce interference with experimental visual stimuli, visibility of the AR interface can be reduced to a minimum when it is currently not required. However, our proposed solution addresses only some limitations of current AR devices. The most crucial limitation, the incapability to use current AR devices in large scale and outdoor environments, still remains. As long as highly accurate and reliable tracking cannot be provided by AR hardware (e.g., realized by a combination of inside-out and satellite tracking), the use of AR devices will be limited to spatially confined environments. 2b1af7f3a8