Spatial UI
Also said as World-space UI, Spatial interface
Interface placed in the game's 3D space that the character can't see: an outline round an enemy, a glowing trail on the ground. It exists in the space but not in the story.
It puts information where you're already looking, so you don't have to glance at a corner. Used everywhere, it covers the world you built with scribbles.
Say it
“Remove the objective text from the corner. Project it on the wall of the room it refers to, in the same font, and let the camera find it.”
Where you’ve seen it
Splinter Cell: Conviction projects its objectives as words onto the walls of the level. Fable III lays a glowing trail on the ground to your objective.
Not to be confused with diegetic ui
A trail on the ground that nobody in the story can see is spatial. If the characters could point to it, it would be diegetic.