Good time of day, in the creation of the next game collided with the need to display the 3D model in the HUD (more precisely in the inventory). It is based on an example of Skyrim.
Q: how it make in UE4, or how in general realize this?
As far as i know, it is only possible to fake this.
There are UMG components for this. I guess something like Viewport.
The issue here is, that UE4 has no render layer infront of the HUD. It will always draw above the ingame scene (that’s why you can’t add a weapon mesh to a shooter character like in Counter Strike, which is just a HUD Fake for the player).
If i understood that correctly, you would need to render the model in an empty space and get it into UMG with this Viewport thing (or was it SceneCapture :X?)
But maybe this gives you enough information to search a bit, because this was asked several times already.
Im making a game, in that game, there’s a legendary item, and its shown as a Cutscene(matine) in a different level, its not rxactly as you want, but i think you can do a Matinee showing a mesh that changes of model depending of the selected item 