We have 3D objects being rendered to the UI via SceneCaptureComponent2D’s and are running into issues where everything is rendered with very low quality textures.
In our scenario, we have a small rig setup really far away from the gameplay area, which contains a small lighting rig and a few static meshes to render onto the UI. Because the static meshes are really far away, they are being rendered by the SceneCaptureComponent2D with their textures on the lowest resolution mip.
Moving the rig right next to the player camera causes these textures to update to the correct mip levels.