Just like the title
I want to make a hol inside a wall

Thnx in advance

You cant, you need to edit the mesh in your 3d program of choice.

Luos is right, SM subtraction isn’t possible in UE4. At least you can merge multiple meshes putting them into the scene, selecting them and clicking on “Merge Actors” into the rightClick Menu.

Thats a nummer

Thnx for the answer

As a follow up to this, what if I wanted to put a door in a wall at a random spot? It’s fine if I leave brushes in, but I don’t want to do that. I have a long wall, and I want the door to spawn at some random position in that wall so that it is different every time. That means I need a random hole.

To achieve this you need a wall mesh with a hole for the door. Then you have to dynamically replace a wall section with the wall and the door (using the same size is better).

So I couldn’t make it truly random. I’d have to split the wall into various segments and randomly replace one? I couldn’t actually just set a random X value from 1-whatever and have it slide along the wall? That’s too bad.

Well, you can always make a wall mesh with a door hole in it and add “shapekeys” (or “morph targets”) for when the door is on either side - then you can just simply randomize the blend between those. Technically you can do that with any side, size, rotation, as long as it’s a single mesh.