More Realistic HoloLens Spectator View Photos

HoloLens Spectator View - Photoshop - Screen - Darkened

When capturing a Mixed Reality scene through HoloLens Spectator View, the resulting photos and videos look amazing. But how to make them more realistic? The right blending mode in Photoshop helps.

Are Spectator View Photos Real?

Of course, the captured Spectator View photo is in many ways different to what you see in HoloLens. First off, it’s only 2D; in the HoloLens, you’d see a real 3D hologram. In this area, the live HoloLens view is much more impressive.

On the other hand, the actual resolution and field of view of the HoloLens is less than a (potentially) 20 Megapixel+ Unity rendering that shows holograms all around you. But the field of view is difficult and somehow unnecessary to simulate as we’re looking on the scene from a 3rd person perspective. Continue reading “More Realistic HoloLens Spectator View Photos”

How to set up HoloLens Spectator View, Bonus – Troubleshooting

HoloLens Delete Space

Did you follow the blog post series on setting up Spectator View for HoloLens? The following issues frequently occured when testing Spectator View. To make your life easier, make sure you check these troubleshooting tips & tricks:

HoloLens Sharing Offset

Between your two HoloLenses, there can be some offset in the placing of the holograms. In one HoloLens, you can for example position your hologram directly on the table; on the second HoloLens, it’s one meter next to the table. Continue reading “How to set up HoloLens Spectator View, Bonus – Troubleshooting”

How to set up HoloLens Spectator View, Part 7 – Mixed Reality

HoloLens Spectator View - Sample Photo

In the final part of the HoloLens Spectator View series, I’ll add the final tweak to my sample project and show you what kind of photos the Compositor actually saves on your PC. Getting to this point has taken a lot more work than expected (+ a lot more blog posts, too!), but I still feel that the journey was worth it! You can finally get great photos and videos of the mixed reality experience on HoloLens.

Script Execution Order

Sending the updates didn’t work right away, so I searched for other changes that the sample does differently from my app that might be responsible. One such case was the Script Execution Order.

In Unity, the order in which scripts are initialized is arbitrary. When debugging, I found an issue that an instance of a class wasn’t available yet when a script wanted to access it. Continue reading “How to set up HoloLens Spectator View, Part 7 – Mixed Reality”

How to set up HoloLens Spectator View, Part 6 – Custom Messages for Sharing

Spectator View - Custom Messages class instance

To make Spectator View work in our own HoloLens project, we actually have to understand how it’s working, what it is doing and how it is related to the HoloLens Sharing Experience. Turns out that there is a lot to do in our app (including transmitting custom messages) to prepare it for the full Spectator View experience!

Synchronizing Objects: Anchor & SceneManager

The Spectator View is based on the Sharing experience of the HoloToolkit, but it contains its own “fork” of the code. Instead of us having to manually decide & code which objects and interactions to send via network messages (as in the normal Sharing use case), the fork of the Spectator View transmits some data by default to our DSLR-mounted HoloLens.

However, it’s important to understand that if you use Spectator View, you also need to integrate most of the Sharing code. Essentially, a lot of code is duplicated between the two frameworks, with only slight differences in order to give the DSLR-mounted HoloLens a special role, plus the PC running Unity also needs to connect in order to correctly render the scene. Continue reading “How to set up HoloLens Spectator View, Part 6 – Custom Messages for Sharing”

How to set up HoloLens Spectator View, Part 5 – Sharing your Scene

SpectatorViewManager - Prefabs

In the previous part, we’ve re-compiled Spectator View using the latest HoloToolkit sources. At the time of writing, this resulted in a compile error, as the HoloToolkit for Unity has seen a breaking change since Spectator View was released.

In this part, we’ll first fix the Spectator View code, and then set it up correctly in our own Unity scene. Then, we’ll need to check several other things: how to launch the Sharing Service, adding Internet Connectivity and the Holographic Camera prefab.

Fixing the Spectator View Code

From the two choices at the end of part 4, of course, we go with the adventurous road to fix the code 🙂

Turns out that the AddSurfaceObject()  method from the base class SpatialMappingSource  was changed. Instead of directly creating a Surface Object from a mesh, this process was now split up into two parts. There is one method to create the surface object, and another one to add it. Continue reading “How to set up HoloLens Spectator View, Part 5 – Sharing your Scene”

How to set up HoloLens Spectator View, Part 4 – Preparing SpecatorView Packages

Getting Spectator View to run with your own app is obviously the most important step. How to include the required tools – including Sharing – into your app using the latest versions?

More specifically, I’ll add Spectator View to my playground project, which is mainly for placing a hologram in the room (with a few other useful scripts). Currently, this hologram is a nice, life-size skeleton from the Unity asset store.

HoloToolkit-Unity & Holographic Academy

The Holographic Academy course 240 explains how to set up your project to include Shared Holograms. It’s a good idea to work through the tutorial, as it will show you some of the basics of what is needed for Spectator View.

However, as with most of the Academy tutorials, it’s quite old. The HoloToolkit has evolved since then, and the demos often have little resemblance to what your project would look like if you start from scratch.

Therefore, for your own project, first clone the HoloToolkit-Unity GitHub repository to your local PC. Open the project in Unity and export the Assets folder to a new package according to the instructions.

Once this is finished, import your newly made, fresh HoloToolkit-Unity package into your own Unity project. Alternatively, you can of course use one of the pre-packaged HoloToolkit-Unity releases, which is slightly older, but is usually a good compromise. Continue reading “How to set up HoloLens Spectator View, Part 4 – Preparing SpecatorView Packages”

How to set up HoloLens Spectator View, Part 3 – First Real-Life Test

HoloLens Spectator View allows capturing high quality photos including the mixed reality contents as seen by other HoloLens users. To test the complete system setup, the next step is running the supplied sample app in Unity.

Based on my previous two blog posts, calibration of the HoloLens in relation to the DSLR camera has been successfully completed. If you need to complete these steps, check out Part 1 and Part 2 first.

Spectator View Calibration Data

The calibration app saved its calculated data file to your Documents\CalibrationFiles  folder. Copy the CalibrationData.txt  file to the Assets -folder of the Sample project that is part of the HoloLens Companion Kit / Spectator View GitHub repository.

The following screenshot shows the contents of the CalibrationFiles  directory, where the app saved both the screenshots of the Canon EOS camera, as well as from the HoloLens. The txt file in the directory is the data file you actually need for your app.

Continue reading “How to set up HoloLens Spectator View, Part 3 – First Real-Life Test”

HoloLens: Adding Fallback Input Handlers for Positioning Out-of-Sight Objects

The TapToPlace  script of the HoloToolkit is a great and simple way to place and anchor holograms in the real world. However, it can be problematic if the hologram is placed out of reach / view from a previous session in another room and you can not tap the hologram to place it closer to you once again.

A good solution is to create another “reset” gesture that triggers object placement even if you don’t directly tap the hologram. An easy way to achieve this is the tap-and-hold gesture, which is one of the standard events the Input Manager of the HoloToolkit can send.

To handle interaction events that don’t target a particular hologram, the current HoloToolkit uses Fallback Input Handlers. However, this functionality isn’t very well documented anywhere. This guide explains how to write a custom fallback input handler.

Continue reading “HoloLens: Adding Fallback Input Handlers for Positioning Out-of-Sight Objects”

How to set up HoloLens Spectator View, Part 2 – Camera Configuration & Calibration

The next step to getting the HoloLens Spectator View to run is the calibration. This needs to be done once after mounting the HoloLens to the DSLR camera. The output is a calibration info file that lists how the position, field of view and other parameters differ between the HoloLens and the DSLR.

Step 4: Camera Setup

By default, the Canon EOS 5D Mark III outputs some information on top of the live HDMI video, including a big white focus rectangle. That needs to be deactivated in order to get a full-screen, clear image.

Switch the camera to movie mode, and in the camera settings menu, page “SHOOT5: Movie”, set “HDMI output + LCD” to “Mirroring”.

Continue reading “How to set up HoloLens Spectator View, Part 2 – Camera Configuration & Calibration”

How to set up HoloLens Spectator View, Part 1 – 3D Printing, Tools and SDKs

We’re developing several HoloLens apps at the St. Pölten University of Applied Sciences, for example in the area of Healthcare and Radiology, as well as for Smart Engineering. For better demonstrations, the HoloLens Spectator View is crucial: it allows taking 3rd person photos and videos of people using the HoloLens app. That helps in understanding the overall scene setup and the interactions between users and the otherwise invisible holograms.

Step 1: 3D Printing the HoloLens Mount

Microsoft has released 3D printing files for the HoloLens mount, which allows fastening the HoloLens on a digital camera. They recommend using Aluminium for better stability. However, we do not have such a metal-based 3D printer, and using an external company would cost several hundred Euros. Therefore, we decided to go with the standard plastic 3D printing instead.

One issue with the current design is that it’s a bit too large for most 3D printers – the mount is a little bit larger than A4. Luckily, our old 3D printer was able to produce the correct size (3DTouch by Bits from Bytes). Continue reading “How to set up HoloLens Spectator View, Part 1 – 3D Printing, Tools and SDKs”