How to work with modular assets in unity?

Question

3D

I'm a total newbie and I've run into this problem. There are floor, wall, ceiling prefabs, etc. .
How to place them in the editor so that they fit perfectly? Help me please.

Answer 1

Refractor 2004 , there is also "vertex snapping" while holding down the V key. you can "dock" one corner to another) though this is more for cubes .. but still.
Vertex Snap if anything at the end of the documentation about how to position objects)
they didn’t even try to look in English.
https://docs.unity3d.com/Manual/PositioningGameObj...

Answer 2

And what exactly is the problem?
You have at least the coordinates and dimensions - you can calculate everything mathematically where someone should be.
If the assets are yours, you can add anchor points to them - anchor points, and align them in the unit.
In general, your suffering is very incomprehensible.