How to make sunken things

[Krio]

It's a LOD thing, isn't it?

So if I want to make sunken park example, i do it normally and then drop below Z axis. Then just agjust LODs too underground or what? Tutorial would be nice 

[jeronij]

You only need underground LODs if you plan traffic pass trough the model. If this is not the case, a simple plane at z=0 will be a good LOD for an underground model.

[Krio]

Thank you