The front and back occlusion relationship of multiple objects in a top-down perspective game

Not sure what you are “solving” here, but this is how layering works:

Three (3) primary ways that Unity draws / stacks / sorts / layers / overlays stuff:

In short, as far as the Standard Rendering Pipeline,

  1. The default 3D Renderers draw stuff according to Z depth - distance from camera.

  2. SpriteRenderers draw according to their Sorting Layer and Sorting Depth properties

  3. UI Canvas Renderers draw in linear transform sequence, like a stack of papers

If you find that you need to mix and match items using these different ways of rendering, and have them appear in ways they are not initially designed for, you need to:

  • identify what you are using
  • search online for the combination of things you are doing and how to to achieve what you want.

There may be more than one solution to try.

For instance, you may even use multiple co-located cameras (along with different Layers and LayerMasks drawn to different-depth Cameras) to more-explicitly control apparent draw ordering.

Additional reading in the official docs:

And SortingGroups can also be extremely helpful in certain circumstances:

Other rendering pipelines may have other ways of layering (HDRP and URP). Go see the latest docs for details.

There’s lots of third party open source packages available as well, such as this:

Beyond that, here is How to report your problem productively in the Unity3D forums:

This is the bare minimum of information to report:

  • what you want
  • what you tried
  • what you expected to happen
  • what actually happened, log output, variable values, and especially any errors you see
  • links to actual Unity3D documentation you used to cross-check your work (CRITICAL!!!)

The purpose of YOU providing links is to make our job easier, while simultaneously showing us that you actually put effort into the process. If you haven’t put effort into finding the documentation, why should we bother putting effort into replying?

If you post code, only post the relevant code and always use the format button above. Do not post photographs of code.