There's Urho3D (https://urho3d.github.io) which seems to be mostly a clone of OGRE. I don't know if any of the same people work on it.
Xamarin have a C# wrapper for it, UrhoSharp (https://developer.xamarin.com/guides/cross-platform/urho/). I'm working with it now and I like it a lot better than Unity so far; but I strongly prefer to work in code rather than doing everything in Unity's IDE.
Urho is so much much more than Ogre3D and it's definitely not a clone of Ogre3D. It's full game engine with a lot of features - audio, physics, navigation, ... while Ogre is basically just rendering library. And Urho's rendering is not closer to Ogre than any other rendering solution out there. The only thing they seem to have in common is that people are slowly losing interest in them, which is unfortunate.
Xamarin have a C# wrapper for it, UrhoSharp (https://developer.xamarin.com/guides/cross-platform/urho/). I'm working with it now and I like it a lot better than Unity so far; but I strongly prefer to work in code rather than doing everything in Unity's IDE.