As we work through these tutorials on the HoloToolkit, I realize that we need a post on how to install the HoloToolkit in your project. While there are many ways to do so, here is my favorite. First, navigate to https://holotoolkit.download. This is a site created and maintained by @withinrafael that creates a Unity Package file each time there is an accepted pull request in the HoloToolkit-Unity project. On the site, the packages are shown with the most recent at the top. You will also see info about what items were included in the latest pull request(s) that triggered the build. Clicking on the package name will cause it to download.
Once you have the package downloaded, you can open your Unity HoloLens project. Once the project is loaded, to import the package, click on the Assets menu, then select Import Package -> Custom Package. This will open a file picker where you can select the package you downloaded earlier. Once you click open, a status bar will show up while it reads the package, and then another window will open that will show all the contents of the package, in this case, the HoloToolkit-Unity items.
You can actually pick and choose what items you wish to import or not this way. This is a handy feature when you are bringing an updated package into an existing project, as this window will show you which files are new, changed, or remain the same.
As a general rule, unless my project is going to implement sharing, I tend to not import that portion of the HoloToolkit. There are some special things needed to make that section compile in your project, and I don’t find it worth the time if I am not doing any sharing in my project.
Once you have the items you want selected, click the import button and the package will load into your project.
If anyone has further questions or comments, please feel free to speak up in the comments section!