Multi‐Region Area Selections (pre‐mod‐rewrite)

To use multiple sub-regions in one schematic, you need to use the Multi-Region area selection mode, and not the default Simple mode. Also note that this is still called Normal mode instead of Multi-Region in all of current the 1.13+ mod versions as of writing this in November 2023. (The Simple mode is meant for quick single box selections, and it's hard coded to only have one region/selection box.)

Quick overview / required steps

To select areas in the Multi-Region mode, you need to first do three things:

• Switch to the Multi-Region (= Normal) selection mode
• Create a new selection save file, or open an existing selection save file
• Create at least one sub-region, and focus that region if you want to use the "tool item" to move it around

Switching the area selection mode

You switch the selection mode in the middle left of the Litematica main menu. (Or in the Area Editor menu, but that has a limitation that you can't switch from Simple to Multi-Region/Normal mode unless you already have a selection save file open via the Area Selection Browser.)

The Multi-Region mode area selections are saved to their own selection/config files whatever you want to call them. This is so that you don't have to keep modifying and re-doing the sub-region boxes all the time if you need to switch between multiple builds/projects. Instead you can save each selection separately and then open it again later if you for example need to save a modified or fixed version of a schematic.

Creating selections and switching between selections

Before you can start selecting stuff, you need to either create a new selection, or open an existing selection. This is done via the Area Selection Browser menu.

So do one of these:

• Click on New selection to create a new selection save file
  • Give it a descriptive name - the name will be the name of any schematics created from this selection. (The schematic name is shown in the Loaded Schematics menu, and it's also the default name for any Schematic Placements created from that schematic.)
• Click on an existing selection save file on the list to open/focus it.
  • The focused selection will have the white outline, and also the name will be shown at the bottom of the screen.
• Click on From Placement to create a new selection save file based on the currently focused Schematic Placement.
  • This will basically re-create the same area selection that was originally used for creating the schematic, except for the possible Manual Origin option. (TODO: I need to verify the behavior with the origin...)

The Configure button on the area save file entries on the list will open the Area Editor menu for that selection. But in general I don't recommend using that button to open the Area Editor menu, as this way you can be editing an area that is not the currently active/focused area. Instead you should use either the openGuiAreaSettings hotkey (Numpad multiply by default), or the Area Editor button that is in the Litematica main menu. Both of those will always open the Area Editor for the currently active area.

Managing the selection - creating, renaming and removing sub-region boxes

Use the Area Editor menu to create, rename, remove and control sub-regions. The default hotkey to directly open the Area Editor menu is Numpad multiply. You can also click on the Area Editor button in the Litematica main menu.

You can click on a sub-region from the list to focus that region to be controller by the tool item or some of the hotkeys. Click on Rename to give the regions meaningful names. You can then for example easily turn on/off the individual regions in the Schematic Placement settings if you want to build things one section at a time.

Note: Don't enable the Manual Origin option unless you know you are going to need it for something!

It's a common mistake to unknowingly enable the Manual Origin option, but then not actually set it anywhere near the build or the areas you are selecting. Then if you save a schematic, you will have that same relative offset from the placement origin to the sub-regions. The result of this is that when you load a schematic and the placement is created, all you see is the 1x1x1 cyan box for the origin point, as all the sub-regions might be somewhere thousands of blocks away in unloaded chunks. You can go to the placement settings and then to the sub-region settings and manually move the regions near where you are, but obviously this is not what you want to happen.

Using the "tool item" to control the selections

First off be aware of the most common "oopsies" for why the tool item might not be working:

• The tool item functionality is disabled (M + T or Generic -> toolItemEnabled)
• The mod main rendering is disabled (M + R or Visuals -> enableRendering)
• You are not holding the item that is configured as the tool item (Generic -> toolItem), or your item has NBT data on it
  • The "older" mod versions (before the big mod rewrite, which has yet to be released in any of the MC 1.13+ mod versions as of late 2023) do not allow any NBT data on the item. You can check this with the vanilla advanced item tooltips feature (F3 + H) and hovering over the item.
• There is also a separate option (Visuals -> enableAreaSelectionBoxesRendering or Hotkeys -> toggleAreaSelectionBoxesRendering) to turn off area selection rendering

You want to be in the Area Selection tool mode (or one of the other "area based" tool modes) if you want to use the tool to control the selection. You can Middle click with the "tool item" to select either the region boxes as whole or one of their primary/secondary corners to control with the tool. Then you can Left click or Right click to place/move the corners, or Alt + scroll to nudge around the selected element in the direction you are looking at.

Note that you don't need to be super close to the elements you want to select, the max range is somewhere around 200 blocks away.

Also I highly recommend using the Expand corner behavior mode instead of the default Corners. You can switch between those modes with Ctrl + M in the Area Selection mode, or using the Corner Mode button in the Area Editor menu.

In the default Corners mode you Left click to set the primary corner, and Right click to set the secondary corner. (Sneak to set it adjacent the pointed block instead of inside it.) But in most cases you don't have blocks in the exact corners of the build, so then you would need to use temporary blocks and derp pillars. This is just unnecessary...

In the Expand mode you Right click to collapse the selection box to the clicked position, and then you can Left click (perhaps multiple times) to expand the selection box around all the blocks you click on. This way you can always select what you want without using any temporary blocks at all. (Unless you also want to select some air around it... but then you can select a corner and Alt + scroll nudge it.)

There are also some related hotkeys for controlling selection boxes. The most useful of them is probably selectionGrow, which allows you to auto-grow the selection box around a free floating build. So you would just Right click once in the Expand corners mode to set the initial box somewhere in the build, and then use the selectionGrow hotkey to automatically grow the selection box around the entire build. Note that there must not be any adjacent/touching blocks outside the build, and thus the build for example can't be on the ground for this to work. Otherwise the selection will just grow around the entire loaded chunks area around the player. The way this grow feature works, is that it expands the box by one block on each 6 sides, and then it checks if that new expansion shell contains at least one block that is not air, and if it does, then it keeps that expansion. And it repeats the expansion as long as there are at least some blocks in the grown new shell.

Here is a 5 second "tutorial" for saving a schematic using the Expand selection mode and the selectionGrow hotkey ;) https://streamable.com/70pmm