Good morning guys.
I know my question sounds a bit strange, so I will try to explain which is my problem and what I need.
I worked a lot on a my own engine for rendering 2.5D with 3D objects on pre-rendered screens (such old Alone in the dark, resident evil etc…)
I tried with a lot of solution, the last one consists using pre-rendered backgrounds+pre-rendered grayscale depth mask to fill z-buffer.
Last solution was very interesting, and worked well for object near cam, but unfortunately I discovered that for far objects the z-buffer precision was not so good.
In my opinion best solution for mid-grounds (so 2D pictures that can be rendered in front or behind 3D objects) would be using planes or boxes with perspective, but with a flat texture, rendered exactly as-is, without any transformation applied.
How is it possible to do it?
In attachment a simple example with my own engine to clarify better my intention.
Thanks a lot and best regards
Ray