How do I reference OpenVR in my project?

1

Currently, I’m trying to create a VR environment in MonoGame and so I need an API to interface with the headset. I decided to use OpenVR since it works best with Valve headsets like mine. However, I haven’t used any APIs before so I don’t know anything about how to reference them.
The OpenVR documentation is very unhelpful for beginners since the only instructions it gives are initialization instructions that assume that you already have the API attached to your project. I’ve looked online to find instructions on how to reference an API but almost every single tutorial is about how to create one, very unhelpful. The little information I did find on referencing APIs in C# projects led me to the “add project reference” dialogue. However, I managed to run into another roadblock as, upon attempting to add the API’s dll file as a reference, Visual Studio gives an error stating “reference is invalid or unsupported”.
Clearly, there are more steps involved in referencing OpenVR in a C# project that I’m unaware of, but I have no way of learning them. I’ve gone through every readme file in this entire API several times and am no closer to understanding any part of it. No one on the OpenVR or VRdev subreddits, the OpenVR GitHub, or Stackoverflow has responded to my posts in over 2 weeks, leading me to believe that either no one knows how to reference this API in a C# project or my understanding of the issue is so far off the mark that no one can figure out what in the world I’m talking about. so to be clear this is my goal:

I want to reference the OpenVR API in my MonoGame project.

This is the current roadblock:
I cannot figure out how to add the reference. When I try to reference the dll file, Visual Studio gives me the error “reference is invalid or unsupported”. There are no clear instructions in the OpenVR documentation nor elsewhere online on how to reference the API.

This issue is infuriating as I’ve been completely stonewalled on this project and I haven’t even gotten to write any code yet. I feel as though I’ve exhausted every available resource to fix this issue; not even my college professors can tell me what I need to do. I know that what I’m trying to do is possible, there are references (vague and unclear as they may be) in the OpenVR documentation to C# methods, and others here on the MonoGame forums have shared VR projects that are compatible with OpenVR platforms, but I just don’t know how to get there from where I am. If anyone has any info on how to reference this API in a C# project or why the normal route isn’t working it would be greatly appreciated.

2

OpenVR is an unmanaged C++ library and cannot be directly referenced in dotNet project.

You will need to run a C++ to CSharp generator to use in a dotNet project or search for a project on github that has already created the CSharp interface.

3

Thanks for the advice. I found a project on GitHub that allows me to interface with the API in C#. It was primarily designed to allow easy development of OVR overlays but allows access to the other APIs as well. This means I’ve finally moved on to figuring out how to display things in the headset (yay!), an equally baffling task.

It seems that rather than being able to tell an application to open inside steamVR or render inside one of the eye cameras, I have to submit a texture to each eye camera every frame (the texture presumably being the 3D scene projected onto a 2D plane). So unfortunately, this won’t be as simple as telling some 3D cameras in MonoGame to send their views to the 2 eye screens. I need to somehow turn the MonoGame rendering output into a texture inside a struct of type Texture_t from the OpenVR namespace and send that texture to the compositor.

In any case, that’s just the next challenge. You have allowed me to at least start this project, so thank you.