Collision with complex models

First of all, forgive me if my question is too basic, because I'm starting with Unity and I still do not know some things.

The thing is, I'd like to know how to add an efficient collision to objects more complex than squares or cylindrical. An example might be a fountain like this:



As you can see, the collision shouldn't be on the same distance at the top as at the bottom.

Is there any way to implement an efficient collision with complex objects?

 

Quite simply you'll be using Mesh Colliders. You will want to take your highly detailed model and make a much simpler version of it to use as the "physics model".

There are some tips to be found all over regarding great methods of tackling this. This one that I replied to was more recent, and does cover what you're asking about.

 

I currently work with 2D projects at Unity, and I think I'll continue this way until I learn a little more, because many of these concepts are totally unknown to me. I don't know anything about modeling, or about 3D animations, for example.

 

Best way I found to learn new concepts is to think of the simplest implementation you can and just go for it using tutorials online.
Blender is actually a pretty easy modeller to get into, it's free, and Unity can directly import Blender's native file format.