How to change window style for hwnd ?

  1. Disable floor
  2. Use that texture in material. Not directly in a widget.
  3. Set Material Domain to “User Interface” and Blend Mode to “Masked”
  4. Attach RGBA output of texture to material’s Opacity Mask input.

This will masks all black color.
But be careful. Your model’s material shouldn’t contain any black color in it.

This is my test view. (It is cube with DefaultColorCalibration texture of Unreal. It has some blacks in it)

this is masking. If there wasn’t any black in model’s material, we could see a better 3d-ish view)

//
Or you can put your model to correct relative location based on camera in player character.
And you can change it’s location with only changing its X-Y axis.

I think creating another window is overkill for that.