Before going further, I would highly recommend to read these articles first:
In this article, you will learn how to export Unity project to Visual Studio. Once your Hologram is complete, so project is ready to be exported to Visual Studio and then to your HoloLens.
Follow these steps to export Unity to Visual Studio.
Performance Setting
Select Edit tab >> Project Setting >> Quality
Select Fastest in Default drop down from QualitySettings.
Build Settings
Select File >> Build Settings
Select Windows Store in the Platform list
Set SDK to Universal 10
Set Build Type to D3D
Specify the export for Windows Holographic
From the Build Settings... window, open Player Settings...
Select the Settings for Windows Store tab
Expand the Other Settings group
In the Rendering section, check the Virtual Reality Supported checkbox to add a new Virtual Reality Devices list and confirm "Windows Holographic" is listed as a supported device.
Export the Visual Studio solution
Now your Unity project has all the settings applied to be properly exported as a Visual Studio solution for a HoloLens app.
Return to the Build Settings window.
Click Add Open Scenes to add the scene
Check Unity C# Projects
Click Build
Click New Folder and name the folder "App".
With the App folder selected, click the Select Folder button.
When Unity is done building, a Windows File Explorer window will appear.
Open the App folder in File Explorer.
Open the generated Visual Studio solution (TestHolograms.sln in this example)
Conclusion
In this article, you have learnt how to export Unity to Visual Studio. If you have any question and comments, then post a comment in C# Corner comments section.