ArUcoDetectionHoloLens-Unity

ArUco marker tracking made available for use in Unity through IL2CPP Windows Runtime support for the HoloLens 1 (x86) and HoloLens 2 (ARM).

Incorporates:

• HoloLensForCV sample from Microsoft, at personal branch
• ArUco marker detection in OpenCV

Requirements

• Tested with Unity 2018.4 LTS and Unity 2019.4 LTS
• Visual Studio 2017/2019
• Minimum RS4, tested with OS Build 17763.678
• Printed (or on screen) ArUco markers. Markers can be readily generated using the following tool

ArUco Detection Sample

1. Git clone repo. From the main project directory, clone submodules with:

git submodule update --init

2. Copy precompiled dlls and HoloLensForCV.winmd file from the Prebuilt->x86/ARM folder to the Assets->Plugins->x86/ARM folder. Due to the naming convention of dlls and winmd files, only one configuration (x86 OR ARM) can be run in Unity at a time.

Optional: build project from source

• Open HoloLensForCV sample in VS2017/VS2019 and install the OpenCV.HoloLens.3411 NuGet package to HoloLensForCV project. In Nuget package manager console type:

Install-Package ..\OpenCV.HoloLens.3411.0.0.nupkg -ProjectName HoloLensForCV

• Build the HoloLensForCV project (x86 OR ARM, Debug or Release)
• Copy all output files from HoloLensForCV output path (dlls and HoloLensForCV.winmd) to the Assets->Plugins->x86/ARM folder of the ArUcoDetectionHoloLensUnity project

3. Open ArUcoDetectionHoloLensUnity Unity project and build using IL2CPP, ensure that unsafe code is allowed under Unity Player Settings->Other Settings
4. Open VS solution, build then deploy to device
5. When looking at an aruco marker from the correct ArUco dictionary: this sample uses the 6x6 (50, 100, 250, 500) dictionary by default, a virtual cube, which is scaled to the size of the ArUco marker, should appear on top of the marker

Using other research mode sensor streams - HoloLens 1 only...

To enable the use of HoloLens research mode streams in Unity, additional permissions are required for the project. Navigate to Unity project build folder and modify the Package.appxmanifest file to include:

• Restricted capabilities package:

<Package 
  xmlns:mp="http://schemas.microsoft.com/appx/2014/phone/manifest" 
  xmlns:uap="http://schemas.microsoft.com/appx/manifest/uap/windows10" 
  xmlns:uap2="http://schemas.microsoft.com/appx/manifest/uap/windows10/2" 
  xmlns:uap3="http://schemas.microsoft.com/appx/manifest/uap/windows10/3" 
  xmlns:uap4="http://schemas.microsoft.com/appx/manifest/uap/windows10/4" 
  xmlns:iot="http://schemas.microsoft.com/appx/manifest/iot/windows10" 
  xmlns:mobile="http://schemas.microsoft.com/appx/manifest/mobile/windows10" 
  xmlns:rescap="http://schemas.microsoft.com/appx/manifest/foundation/windows10/restrictedcapabilities" 
  IgnorableNamespaces="uap uap2 uap3 uap4 mp mobile iot rescap" 
  xmlns="http://schemas.microsoft.com/appx/manifest/foundation/windows10"> 

• Modified capabilities with with new package:

  <Capabilities>
    <rescap:Capability Name="perceptionSensorsExperimental" />
    <Capability Name="internetClient" />
    <Capability Name="internetClientServer" />
    <Capability Name="privateNetworkClientServer" />
    <uap2:Capability Name="spatialPerception" />
    <DeviceCapability Name="webcam" />
  </Capabilities>

Now, modifying the selected sensor for streaming in Unity (for depth and infrared streams, more processing of input frames will likely be required to visualize) different streams can be selected. ArUco marker tracking is currently only supported using the photo-video camera of the HoloLens 1 and HoloLens 2.