Generate a Minecraft dropper struct...

Generate a Minecraft dropper structure: a very tall, deep vertical open shaft (falling straight down), themed as a futuristic sci-fi city seen from above while falling through it. Include obstacles resembling floating skyscrapers/buildings of varying heights and widths, plus a few elongated "flying car" shaped obstacles, all positioned as static obstacles inside the shaft. The shaft must remain a hollow, open vertical column overall — obstacles should stick out from the walls or float inside, but must never fully block any horizontal cross-section. At every height level, there must always be at least one clear vertical path with no obstruction, so a falling player can always find a way through without touching anything. The bottom of the shaft should be a flat open floor (no need for wa