Adding objects into level

I'm building a small level which has a golf course.
Up until now, I'm creating the level in one blender file and importing it in Unity.
But, as I begin to need some things to be separate gameobjects I'm having difficulties in deciding how to proceed.
Here you can see the golf course and the hole is where the axis is located.


The hole gameobject:


In this case, I see two options and as I'm a noob-level-builder I would like to hear from more experienced people on what's better:

• Cut a hole in the level mesh (in Blender) to place the hole gameobject in Unity.
• Merge the hole mesh into the level (in Blender) and in Unity add an empty object at that position with the needed scripts/colliders/etc
• ?

 

The way I did this for my golf courses is to use the Blender3D boolean modifier to cut out the holes in Blender. That way the golf course surface can be all one contiguous mesh.

See the enclosed .blend file for a golf course with two boolean-cut "live" holes in it, one by a straight cylinder and one by a bevelled cylinder.

Note that I put separate materials on each object (golf course, straight cutter, bevelled cutter), and that I unwrapped all objects fully (just a simple smart unwrap), and finally: I put ALL THREE materials on the course itself, such that when the boolean tool cuts it out, it "paints" the other materials inside the holes.

You can do it all with one material too, but at least the above kinda gives you some flexibility. I colored the materials in Blender but I always reassign new materials in Unity so I can control it more precisely, adjust the shader, etc.

Also, after importing it into Unity3D, you have to disable the cutters, as they will be solid geometry that is no longer needed. I leave them in the Blender file so you can move them around (in blender) and adjust the precise position of your holes.

Try to avoid renaming the blender object names AFTER you first name them and Unity reimports them, since they will become fresh objects to Unity and your prefabs will get all conflustercated.

I leave it to you to import the objects, put colliders on it, stick sensors (triggers or what have you) and so on.

Note also I made the golf course itself not flat but rather a volume. If you make it flat then the Boolean tool might not cut quite the way you expect it. I also hide the cutters in the .blend file too so you can see them by quick render in Blender.

Here is a quick render from Blender:

 

Thanks @Kurt-Dekker! I'll take a look at the blend file.
Yesterday I started doing something like you say, using the knife to cut a hole in the mesh and joining the "holes" to the terrain. And then in Unity adding some colliders and triggers to detect the ball.

 

ProBuilder is something I have on my wanting-to-try list, maybe it's time to do it. Thanks @gabrielw_unity!