Shade part of an object?

Unity Engine
1

For instance, A cube:

  • Perfect solution: I would like to show a % of the object from the bottom, with the rest being transparent. This can be static, so in other words once the scene is built, I do not need to change the object. Can this be done?
  • Workable solution: Just show the bottom plane of the cube, with the rest being transparent. Can this be done?

I am not even sure if I am looking in the right place (i.e. shaders), so any help at this stage would be appreciated.

NOTE: For my purposes, the cube us essential, I can not use 6 planes. I am currently, out of control, going down the rabbit hole at the moment, looking at stuff like culling, clipping, etc. So if you can even tell me I am looking in the wrong places, that would be helpful at this stage.

2

I think this video helps me accomplish my perfect solution. With no need of the scripting part as my effect will be static. I’ll let you know how it goes.