Curves 201: Lesson 3
Circular Hole in the Floor/Ceiling
What if you want a hole in the ceiling or floor? Well luckily for you, it's not any more complicated than a dome or corridor, so this lesson should be a breeze!
First, because we want the hole to go somewhere, create another room below the first with a short "hallway" (although it will be a vertical hallway) between the two. For this tutorial, I simply duplicated the top room (curves and all), patched up the walls, and put it on the underside. You don't necessarily need to do this, but feel free to if you think you're up to the challenge. (: As long as you have a small "hallway" in between the two, you can add your circular hole:
Next, draw a brush so that it fills one fourth of the hole, from top to bottom. Convert it into a bevel and add an inverted endcap like you did for the dome. Duplicate your completed corner, Z rotate it, and put it in the next corner. Repeat for the remaining two corners.
That's it! Compile, and your hole is complete.