So I can take a Scene capture cube, render it to a material with the texture hooked with the reflection vector and place the material on the mirror mesh, However, how can I create a blueprint to create a scaling based on player distance.
I know how I could calculate the distance every frame between my player and the mirror. I can i create in effect in the mirror to scale (only in the render) the items in the environment?
If you use 4.12 or later we now have Planar Reflection actors that are useful for mirrors.
You can read about them here: Planar Reflections in Unreal Engine | Unreal Engine 5.1 Documentation
UE4 has support for real-time Planar Reflection that can give more accurate looking reflections than Screen Space Reflections (SSR) provide but come with a higher rendering cost. This higher rendering cost is due to how Planar Reflection works, as Planar Reflection actually renders the level again from the direction of the reflection.
This was what I was going to suggest - render the same object twice with the second one flipped according to the angle. I am glad to see that the engine now has something built-in to do that for us at a lower level (likely a much more optimized solution as well).
That works great! Thanks!