Block Grep

Highlights every occurrence of a block pattern near you.

Patterns can be 1D, 2D or 3D, and you can search for shapes and groups of different
blocks, including wildcard (?)

Usage

The easiest way to configure the mod is using the GUI settings screen. This can
be started with the command /blockgrep config, or you can go to
Options → Controls → Key Binds → Block Grep and assign “Open pattern settings” a key.

On Fabric, if you have Mod Menu installed, it’ll appear in the mod menu list.

In the settings screen you can create new patterns and configure their rendering
settings.

Commands

You can configure the mod entirely using commands if you wish.

/blockgrep pattern [symmetry] <spec>   add a shape of any dimensions
/blockgrep box <x> <y> <z> <blocks>    add a uniform box
/blockgrep list                        show the saved patterns
/blockgrep toggle <n>                  turn one on or off
/blockgrep only <n>                    enable one, disable the rest
/blockgrep all on|off                  every pattern at once
/blockgrep name <n> <text>             rename one
/blockgrep remove <n>                  delete one
/blockgrep radius <blocks>             4–128, default 32
/blockgrep limit <count>               default 512
/blockgrep config                      open the settings screen
/blockgrep status
/blockgrep off

Pattern syntax

Patterns are made of cell predicates, each of which tries to match a block:

| Form | Meaning |
|—|—|
| mud | that block (namespace defaults to minecraft) |
| mud,dirt | Either mud or dirt |
| mud,dirt,grass_block | Either mud or dirt or a grass block |
| #minecraft:trapdoors | any block with that tag, ie. any trapdoor in this example |
| ? | any block, including air |
| !air | anything the rest does not match |

These are combined into larger patterns using , | and ||. So,

| Form | Meaning |
|—|—|
| mud mud | Two mud blocks beside each other (east-to-west) |
| mud \| mud | Two mud blocks beside each other (north-to-south) |
| mud mud \| mud mud | Four mud blocks in a 2×2 square |
| mud,dirt mud,dirt \| mud,dirt mud,dirt | Four blocks of mud-or-dirt in a 2×2 square |
| stone stone \| stone stone \|\| mud mud \| mud mud | A 2x2x2 cube with stone on the bottom layer and mud on the top layer |

Examples

• A 2×2 square of mud and/or dirt:
• /blockgrep box 2 1 2 mud,dirt, or
• /blockgrep pattern mud,dirt mud,dirt | mud,dirt mud,dirt

• A grass block above another grass block:
• /blockgrep pattern grass_block || grass_block

• A 2×2 of mud, with anything (or nothing) above it:
• /blockgrep pattern mud mud | mud mud || ? ? | ? ?

• Any 2×2 of logs, of any wood type:
• /blockgrep pattern #logs #logs | #logs #logs

Dimensioned form

A pattern can also be given as explicit dimensions followed by x·y·z cells, in
x then z then y order:

/blockgrep pattern 2 2 2 mud mud mud mud #logs ? ? #logs

Symmetry

By default a pattern is matched at all four compass orientations. An optional
symmetry spec before the pattern changes that. It is up to three axis letters —
lowercase to allow rotation about that axis, uppercase or absent to pin it — with
h and v to allow horizontal and vertical mirroring.

/blockgrep pattern XYZ   mud ? | ? mud     only as written        (1)
/blockgrep pattern y     mud ? | ? mud     four compass turns     (4, the default)
/blockgrep pattern yh    mud ? | ? mud     ...plus horizontal flips  (8)
/blockgrep pattern yv    mud ? | ? mud     ...plus a top-to-bottom flip (8)
/blockgrep pattern yvh   mud ? | ? mud     both mirror families   (16)
/blockgrep pattern xyz   mud ? | ? mud     all 24 rotations of the cube
/blockgrep pattern xyzvh mud ? | ? mud    all 48, reflections included

Mirror planes can also be named individually after a +, by the axis normal to
each: +x is the east-west flip, +y the top-to-bottom one, +z north-south.
So yh is exactly y+xz, and yv is y+y.

Three things are worth knowing:

• Rotations about two different axes generate rotations about the third, so xy, yz, xz and xyz all mean the same 24 orientations.
• Reflections are not implied by rotations. An L-shape and its mirror image are different shapes however you turn them, which is why h and v exist.
• Mirrors are only interchangeable because of rotation. With the four turns of y in hand, +x and +z name the same eight orientations; with no rotation at all they are genuinely different flips, and XYZ+xz gives four orientations because composing the two mirrors produces a 180° turn.

Symmetric shapes are deduplicated, so each occurrence is reported once however
many orientations were searched.

Cheating

**Note: this mod _can_ be used as an ore-finder so it should be considered a
bit cheaty.** Removing X-ray mode for a “lite” non-cheaty version was considered,
but you’d still be able to look for, say, valuable ore below a grass_block or
stone, highlighting that less-valuable block, so while removing X-ray mode
would limit bulk cheating, it wouldn’t make it a fair non-cheaty mod to use.