Advanced

The five capabilities in this chapter sit on top of the basic edit loop. You can author a usable tile without ever touching them — but they are what turn a slow, repetitive workflow into a fast one.

• Selection — pick a region of voxels for bulk operations
• Transform — move, rotate, scale, flip, and mirror selections
• Symmetry — auto-mirror every edit in real time
• Procedural Shader — generate voxels from a GDScript expression
• Spawn Points — place metadata for the host game

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Selection

Press S or click the Select button to enter Select mode. The sub-tools area changes to show four selection methods. Pick one, build a selection by clicking in the viewport, and the Transform bar (right of the viewport) lights up.

Selected voxels are drawn with a cyan wireframe overlay.

The four selection sub-tools

	Tool	Behaviour
	Face (Magic)	Click a voxel — flood-selects all voxels reachable along the exposed face you clicked. Stops at any face that’s hidden behind another voxel. The right tool for “select this whole wall surface but not the wall behind it”
	Rect (Box)	Click two corners of a 3D box. Everything inside the box — air or solid — is selected
	Brush	Click and drag with a circular brush; voxels under the brush join the selection. Brush size is set in the context bar (1–16)
	Object	Click any voxel — selects the entire 6-connected blob it belongs to. The right tool for “grab this whole connected piece”

Adjusting an existing selection

Action	How
Add to selection	Hold Shift while clicking with any selection sub-tool
Remove from selection	Hold Alt while clicking with any selection sub-tool — works as a “selection eyedropper”
Replace selection	Click without modifiers — the new selection replaces the old one
Clear selection	Esc with no other action in progress
Select all	Ctrl+A — selects every non-air voxel in the tile

Selection-with-filters

In the context bar you’ll find three filter buttons that constrain Face / Object selections to voxels with matching attributes:

Filter	Effect
Geo	(Default) Any 6-connected voxel counts as part of the blob
Material	Only voxels with the same base material type (stone, water, …) join the selection
Color	Only voxels with the same palette index join the selection

For Brush mode, the Brush Size spinner sets the circle radius (1–16).

What you can do with a selection

Once you have a selection, the Edit menu and the Transform bar offer a long list of operations. The Edit menu shortcuts:

Operation	Shortcut	Effect
Copy	Ctrl+C	Copy selected voxels to the clipboard
Cut	Ctrl+X	Copy + delete
Paste	Ctrl+V	Enters paste mode — see below
Delete	Del	Remove selected voxels
Select All	Ctrl+A	Select every non-air voxel

Paste mode

After Ctrl+V, the clipboard’s voxels appear as a floating preview that follows the cursor. The voxels are not yet committed.

Action	Effect
Move mouse	The preview follows
Click	Commit the paste at the current preview location
Esc	Cancel — the preview is discarded

The paste anchors to the same face logic as Add — it lands on the voxel face you click, or on Y = 0 if you click empty space.

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Transform

When a selection exists, the Transform bar runs vertically along the right edge of the viewport. Buttons activate gizmos in the viewport — drag the gizmo handles to perform the transform interactively.

	Button	Behaviour
	Move	Three axis arrows + three plane handles + a centre handle. Drag an arrow for axis-locked movement; drag a plane handle for two-axis movement; drag the centre for free movement
	Rotate	Three coloured rings (red = X, green = Y, blue = Z). Drag a ring to rotate around its axis. Hold Shift to snap to 45° increments
	Scale	Cube handles at corners and edges. Drag a corner for uniform scale; drag an edge handle to stretch along one axis
	Flip	Pop-up menu with X / Y / Z. Mirrors the selection within its current bounding box. Doesn’t change position
	Mirror	Pop-up menu with X / Y / Z. Duplicates the selection and flips the duplicate. Original stays. Result is symmetric around the selection centre
	Hollow	Removes interior voxels from the selection. Only voxels with at least one exposed face survive
	Flood	Fills enclosed air pockets inside the selection’s bounding box with the active palette colour

Confirming and cancelling

A transform is not committed the moment you stop dragging. The viewport stays in a pending-transform state — you can keep adjusting until you commit.

Key	Effect
Enter	Commit the pending transform
Esc	Cancel — voxels snap back to their original position
Arrow keys	Nudge the selection one voxel at a time on the X / Z axes. Shift+arrow nudges on Y

This commit-then-keep-editing model makes precision fixes easy: hit Move, drag roughly to the right area, then nudge into place with arrow keys before committing.

Selection menu transforms (no gizmo)

For one-shot transforms the Selection menu offers direct commands without going through the gizmo:

Command	What it does
Rotate X / Y / Z	90° rotation around the selection centre on the chosen axis
Flip X / Y / Z	Mirror within the selection bounds
Mirror X / Y / Z	Duplicate-and-flip — keeps the original
Scale 0.5× / 0.75× / 2× / 3× / 4×	Resample the selection
Hollow	Remove interior voxels
Flood Interior	Fill enclosed air
Dilate	Grow the selection outward by 1 voxel
Erode	Shrink the selection inward by 1 voxel

These commit immediately — there’s no gizmo phase.

Dilate + Erode are the easiest way to clean up rough geometry. Erode→Dilate strips off thin protrusions; Dilate→Erode fills small holes.

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Symmetry

Symmetry runs your edits through one or more mirror planes in real time. Place a single voxel on the left side of the tile with X-symmetry on, and a matching voxel appears on the right.

The three axis planes

Three buttons sit just below the main mode buttons on the left sidebar:

Button	Plane	What it mirrors
X	YZ at tile centre X	Left ↔ right
Y	XZ at tile centre Y	Top ↔ bottom
Z	XY at tile centre Z	Front ↔ back

Toggle each independently — multiple can be active at once. With X + Z both on, every edit is replicated four times (origin + X mirror + Z mirror + both).

The active planes are drawn as translucent coloured rectangles in the viewport: red for X, green for Y, blue for Z.

Custom mirror planes

The three axis planes pivot at the tile centre, which isn’t always where you want symmetry. Custom mirror planes let you pivot anywhere.

Two buttons handle custom planes:

Button	Effect
Place	Enters placement mode — click a face to drop a mirror plane at that face’s position, with the face normal as the mirror axis
Clear	Removes all custom mirror planes

The right panel shows a list of all placed custom planes; Remove Selected in that list removes a single one. Custom planes appear in the viewport as translucent yellow rectangles.

Custom planes apply to: Add, Subtract, Paint, Fill, Extrude, Select, and Paste. They do not apply to procedural shader output (which generates from a closed expression).

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Procedural Shader

The procedural shader tool generates voxels by evaluating a GDScript expression at every position in a chosen region. Open it via the sidebar Shader button (Add mode), or via Edit → Procedural Shader…

How it works

1. Click two corners of a Box-shaped region in the viewport
2. The shader dialog opens — pick a preset, or write a custom expression
3. Click Apply — the region is filled according to the expression

Each voxel position runs through your expression. The expression’s output is a voxel ID (palette index) — return 0 for air, any positive integer to place that palette entry.

Variables available in your expression

Variable	Type	Meaning
x, y, z	int	Voxel position in tile space
current	int	The voxel ID currently at this position
sx, sy, sz	int	Region size on each axis
cx, cy, cz	float	Region centre coordinates
nx, ny, nz	float	Position normalized to 0..1 across the region
ox, oy, oz	int	Region origin (corner with smallest coords)
vid	int	The active palette entry’s voxel ID — useful as the default fill colour
PI, TAU	float	Math constants

You can call any GDScript math function — sin, cos, sqrt, abs, min, max, clamp, floor, ceil, round, pow, fmod, randf_range, noise.get_noise_3d, …

Built-in presets

Twelve presets cover the common shapes:

Preset	Generates
Sphere	Solid sphere filling the region
Hollow Sphere	Sphere shell, 1 voxel thick
Cylinder (Y)	Vertical cylinder spanning the region’s height
Torus (Y)	Donut ring around the Y axis
Arch	Half-torus arch sitting on the floor
Dome	Upper hemisphere
Noise Terrain	Hilly terrain — sine + cosine waves on X and Z
Pyramid	Stepped pyramid
Cone (Y)	Tapering upward to a point
Stairs (Z)	Ascending staircase along Z
Spiral (Y)	Helical column
Checkerboard	3D checkerboard pattern
Clear	Sets every voxel in the region to air

Each preset is a starting point — pick one, then edit the expression to taste.

Example: a column with arrowslit windows

# A solid cylinder of stone (vid 1) with horizontal slit windows every 10 voxels.
var dx = x - cx
var dz = z - cz
var r = sqrt(dx * dx + dz * dz)
var radius = min(sx, sz) * 0.4
var slit = (y % 10 == 5) and (abs(dx) > radius * 0.6)
return 0 if slit or r > radius else vid

Errors

If your expression has a syntax error or runtime exception, the dialog shows a red error label with the exception message. The region is not modified — you can fix the expression and click Apply again.

The procedural tool ignores symmetry planes — it generates from a closed expression rather than running per-edit. If you need symmetry on a procedural shape, mirror the result after it’s generated using the Selection menu.

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Spawn Points

Spawn points are non-geometric metadata anchored to specific voxel positions. The host game reads them at world-load time to place enemies, items, particles, and so on.

Press K or click the Spawns button on the left sidebar. The sub-tools area shows the registered spawn types, grouped by category.

Built-in types

Type	Category	Used for
Spawn Point	Player	Generic player spawn marker
Enemy Spawn	Combat	Enemy placement (with enemy_id property)
Item Spawn	Loot	Pickup item placement
Weapon Spawn	Loot	Weapon pickup placement
Loot Chest	Loot	Container with loot table reference
Puzzle Point	Puzzle	Puzzle trigger / element
Secret Point	Puzzle	Hidden area marker
Trigger	Logic	Generic trigger zone
Waypoint	Navigation	Pathfinding waypoint
Particle Effect	Visual	Scene-emitted particle (configurable scene path)
Shader Plane	Visual	Custom surface shader (configurable shader path, double-sided flag, surface offset, inset)

The spawn-type registry is extensible — your game-side code can register additional types, which will appear in this list automatically.

Placing a spawn point

1. Press K to enter Spawns mode
2. Click the type you want in the sub-tools area
3. Click a voxel in the viewport
4. The metadata edit dialog opens, pre-populated with the type and the clicked position

The metadata edit dialog

The dialog has four sections:

Section	Fields
Position	Read-only X / Y / Z (set by the click)
Type	Dropdown to switch type after the fact
Properties	Free-form key/value pairs. Add Property appends a new row
Type-specific controls	Only shown for Particle Effect and Shader Plane types — see below

Particle Effect controls

Field	Type	Effect
Scene path	path picker	The .tscn file emitting the particles
Auto Start	checkbox	Start emitting on world load
One Shot	checkbox	Emit a single burst then stop

Shader Plane controls

Field	Type	Effect
Shader path	path picker	The .gdshader file applied to the plane
Surface offset	float	Distance the plane sits from the voxel surface
Inset	float	How far inside the voxel volume the plane lives
Double Sided	checkbox	Render both sides of the plane

Editing or deleting an existing spawn point

In Spawns mode, hovering over a previously-placed spawn highlights it in cyan. Click it to reopen the metadata edit dialog. The dialog shows a Delete Point button at the bottom — clicking it removes the spawn.

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Remote sync (briefly)

The Remote menu connects the editor to an asset-sync server for collaborative work:

Command	Effect
Browse Remote Assets…	Open a browser to download tiles / palettes from the server
Push Current Tile	Upload the active tile
Push Current Palette	Upload the active palette
Sync Settings…	Configure server URL and credentials

The status bar’s Remote: Connected / Disconnected indicator shows the live state. Remote sync is optional — the editor works offline.

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Next

The final page is the Reference — every keyboard shortcut and menu command in one place.