How to "cut" with a building into the ground

I need to “cut” with my building into the ground, as there are stairs in the
underground level etc. When I just place the model, the normal ground will
flow through my building. How can I “exclude” the earth ground from going into
my model? I tried with using terraforming, but with that its not possible to
cut it “hard” enough - I cannot get a convincing transition using
terraforming. The resolution is too low.

To make it more clear, here an
example picture. The normal ground level will be on “ground level” and the
“deeper than ground level” should still be visible. If it makes any
difference, I’m using blender for creating my models. Many thanks in advance!

Hi. A simple answer - you can’t. This has been asked for many months, but
apparently either this can not be done or this has an extremely low priority.
limitation/402622/2> You have to do this somehow with the slopes.

Thank you very much. I think the links are pointing to a closed section if the
forums as I cannot access it. Buy your answer helped but it is sad that it is
not possible.

Here is the basic idea:

The terrain system and the is
sdk is fully capable of cutting perfect holes into the ground…but not
everywhere you want! Lets get deeper and dig some more (Ahahah), enable
wireframe mode via the dev bar
the terraforming rectangle (of course with falloff 1) is born to be aligned
with the World tiles grid What the tool does is setting a defined altitude
(height) for each point of the grid, those point are equally spaced based on
the resolution of the mesh (ore some other quirks, i have to do some deeper
research!) The rule is that you can move each point of the world mesh only in
Z direction (height), and you can’t of course add points, therefore…
As soon as you rotate the
rectangle, the “issue” occurs, But it is not an issue, it is by design, and
VERY unlikely to be solved, the only way to “solve” it is to increase the
terrain mesh resolution, smaller grid, less jagged edges
The solution? Dig a bigger
hole, then fill the gaps! You can create every kind of mesh in blender with
any kind of texture, if you want your planes to drive onto your mesh give it a
road/collision material Hope this helps!

Hello, Thanks @mamudesign for bringing more useful information! Unfortunately,
as stated by @DrzewieckiDesign and yourself above, we currently have no
bandwith to improve that, and I don’t think it will be possible this year.

I think what @mamudesign is what’s always been done in FS to create complex
“ground”. Build the ground you want with an object, and fill a bigger hole in
the landscape with that object.

it would be awesome when every polygon point can be edit in terraforming mode.