The 2.5D kits

The kits filed under 3D are pseudo-3D. There is no 3D engine underneath — they use the same 2D renderer as everything else, with techniques that were invented precisely because 3D hardware did not exist yet. They are fast, they run everywhere, and they are far easier to reason about than a real scene graph.

Raycasting — First-Person Maze, Blank 2.5D

The world is a grid. For every vertical column of pixels on screen, a ray is cast until it hits a wall; the distance decides how tall to draw that column. Near walls are tall, far walls are short, and that alone produces perspective. This is how Wolfenstein 3D worked.

Behaviour: raycastRenderer
  resolution    320    internal width; lower is faster and blockier
  fov           66     field of view in degrees
  viewDistance  20     how many cells before it fades out
  ceiling/floor        colours above and below the horizon

Movement uses firstPersonController, which resolves each axis separately — so walking diagonally into a wall slides you along it instead of sticking.

Mode-7 — Kart Racer, Rail Shooter, Endless Runner

A flat top-down image is sampled one screen row at a time. Each row stands for a fixed distance ahead of the camera, and rows nearer the horizon sample a wider span of the map. The result is a ground plane in perspective. The SNES did this in hardware.

Behaviour: mode7Renderer
  track          which texture to project
  wrap           true = tiles forever (runner, shooter)
                 false = a finite map (the kart circuit)
  cameraHeight   how high the camera sits
  focalLength    with cameraHeight, sets how fast the ground recedes
  horizon        0..1, where the horizon sits on screen
  drawDistance   beyond this, ground fades into haze
  billboardTag   which tag gets drawn as approaching sprites

Billboards

Other karts, enemies and obstacles are ordinary 2D sprites scaled by distance. They are drawn by a separate proxy image, so the entity itself stays where its AI put it in the top-down world — the projection never moves the real thing.

Retuning them

Because the karts still drive around a normal top-down world, everything you know about the 2D racer applies: the same handling values, the same lap logic, the same AI. Only the camera differs. Select the renderer entity and change its settings in the inspector.