Hey. I am new to Recurrent Complex and so far I am not good at this mod. I want to learn how to create my own structures and decided to start with a simple one. I built a small structure, selected it using the "Block Selector", entered the command "/#export", entered "test" in the "Structure ID" field and clicked "Save". (Screenshot 1)

After that, for verification, I manually generate the structure using the command "/#gen test". As you can see in the screenshot, my structure was generated one block lower than it should. (Screenshot 2)

Now I have selected the structure and left the space in one block below it. (Screenshoot 3)

As you can see, now the structure was generated normally, but the problem is that empty space has formed under it. (Screenshoot 4)

Yes, I can place any blocks under my structure to fill the empty space, but is this the only way out? I would like the structure to be generated on a "natural" surface. Is this possible? If so, how to do it?

I've had the same problem with an underground bunker design.

Have you tried using the block : 'Solid(0 ~ Natural floor)' in the air space under your 'test' build and then lower the structure down 1 ie; #export test, Structure Gui comes up, click Generation, Generation Type Gui comes up, click the Edit button next to Natural, Natural Gui comes up, click Placer, Placer Gui comes up, then type 1 in the Baseline field.

This should put you structure (including the new blocks that will replicate the surface in a biome) at the correct position. Took me ages to figure out this.

Hope this helps