How to install Infer.NET to Unity 2018.3

Question

I have a fresh Unity project and following the instructions in Using .NET 4.x in Unity, i've downloaded Microsoft.ML.Probabilistic.Compiler NuGet package from the gallery and copied the DLL to Assets/Plugins. After this Unity outputs an error message

Assembly 'Assets/Plugins/Microsoft.ML.Probabilistic.Compiler.dll' will not be loaded due to errors: Unable to resolve reference 'Microsoft.ML.Probabilistic'. Is the assembly missing or incompatible with the current platform?

I downloaded and copied the missing DLL and every following missing DLL dependency

Microsoft.ML.Probabilistic.dll
System.CodeDom.dll
Microsoft.CodeAnalysis.CSharp.dll
Microsoft.CodeAnalysis.dll
System.Collections.Immutable.dll
System.Reflection.Metadata.dll

Unity showed no more errors after adding the System.Reflection.Metadata.dll.

When i add

using Microsoft.ML.Probabilistic;
using Microsoft.ML.Probabilistic.Compiler;

to a script, the project builds fine in both Unity and Visual Studio Community, but when i attempt to use the libraries, namely the Microsoft.ML.Probabilistic.Compiler.Variable<T> class

using UnityEngine;
using Microsoft.ML.Probabilistic;
using Microsoft.ML.Probabilistic.Compiler;

public class Main : MonoBehaviour {
    void Start () {
        Variable<bool> firstCoin = Variable.Bernoulli (0.5);
    }
}

both Unity and Visual Studio fail with

Assets/Scripts/Main.cs(7,3): error CS0246: The type or namespace name 'Variable<>' could not be found (are you missing a using directive or an assembly reference?)

and

Assets/Scripts/Main.cs(7,30): error CS0103: The name 'Variable' does not exist in the current context

Adding -r:Microsoft.ML.Probabilistic.Compiler.dll to Assets/mcs.rsp file generates an error

Microsoft (R) Visual C# Compiler version 2.9.1.65535 (9d34608e) Copyright (C) Microsoft Corporation. All rights reserved.

error CS0006: Metadata file 'Microsoft.ML.Probabilistic.Compiler.dll' could not be found

The project configuration is

Unity 2018.3.10f1
Visual Studio for Mac Community
Build Settings/Platform: iOS
Player Settings/Scripting Runtime Version: .NET 4.x Equivalent

it makes no difference whether i set

Player Settings/Api Compatibility Level: .NET 4.x

or

Player Settings/Api Compatibility Level: .NET Standard 2.0

Other settings are left to their defaults.

I haven't added the DLLs to the vs-project in Visual Studio as the guide says

Visual Studio regenerates .csproj and .sln files for Unity projects each time they're opened. As a result, you cannot add assembly references directly in Visual Studio because they'll be lost upon reopening the project. Instead, a special text file named mcs.rsp must be used:

Create a new text file named mcs.rsp in your Unity project's root Assets directory.

On the first line in the empty text file, enter: -r:System.Net.Http.dll and then save the file. You can replace "System.Net.Http.dll" with any included assembly that might be missing a reference.

Restart the Unity editor.

Nothing is done in Visual Studio. As the Microsoft guide says it would get overwritten and lost anyway. — Matti Jokipii, May 07 '19 at 10:28

score 1 · Accepted Answer · answered May 17 '19 at 13:22

Variable<bool> Isn't part of either Probabilistic or Probabilistic.Compiler

Instead you need to include using Microsoft.ML.Probabilistic.Models;, of which Variable<T> is part.

using UnityEngine;
using Microsoft.ML.Probabilistic.Models;//we need Probabilistic.Models

public class SomeScript : MonoBehaviour
{
    void Start()
    {
        Variable<bool> firstCoin = Variable.Bernoulli(0.5);
    }
}

Tested this with unity 2018.3 and 2019.1, both with .net 4.x runtime, and it builds fine (Although on Windows, it shouldn't make a difference).

... and copied the DLL to Assets/Plugins. After this Unity outputs an error message

I personally didn't have to do this to get it to work. I downloaded the package from NuGet straight into the default directory (project/Packages/) using Install-Package Microsoft.ML.Probabilistic.Compiler -Version 0.3.1810.501. It also didn't require me to download any additional DLL's.

Yes, yes, that's it! Thank you so much! Unfortunately Infer.NET model builder doesn't work with IL2CPP AOT compiler on iOS. ATM i see this impossible. Nonetheless your answer solved the problem i thought i had with the installation and Infer.NET does work in the Unity editor. — Matti Jokipii, May 18 '19 at 08:51

How to install Infer.NET to Unity 2018.3

1 Answers1