---
title: "3D Geometry Builders"
package: "@phaser-ae/geometry-3d"
tier: Free
version: 3.0.0-4
released: 2026-10-14
updated: 2026-10-20
description: "A mesh-modelling toolkit in code: primitives, lathes, sweeps, vessels, leaves, deformers, scattering, coating, plane slicing, polyhedral dice and CSG booleans."
url: https://phaser.io/packs/geometry-3d
site: Phaser - https://phaser.io
---

# 3D Geometry Builders

A mesh-modelling toolkit as pure functions: primitives, lathes, sweeps, vessels, leaves, deformers, scattering,
coating, plane slicing, numbered dice and CSG. You make the shape in code, register it once, and from then on it is an
ordinary mesh your game instances.

## What it does

Every builder returns a triangle soup: a flat array of vertices, each with a position, a normal and a uv. Curved
surfaces carry smooth normals, so they light as real 3D rather than faceted. You register a soup with
`game.world3d.defineMesh(name, verts)`, or compose the pack and `define` a builder by name so `world3d.mesh(name, opts)`
and `spawn({ mesh: name })` build it on first use. The 3D world makes its own meshes from these functions, and the
procedural model specs of `model-3d` build their forms from them.

There are two families. The primitives are unit-sized and scaled at spawn: boxes and rounded boxes, spheres,
cylinders, cones, capsules, tori, torus knots, wedges, planes, panels, discs, rings and the platonic solids, each with
its own segment counts, radii and an `arc` to cut a wedge out of anything round. The smooth forms are built at a real
size in metres, so a bend or a wall keeps its proportions: a lathe from a profile, a section swept along a path, a
hollow vessel with a fill level, a leaf with fold, curl and twist. Deformers squash, lobe, taper, twist, add noise and
bend; scatter helpers place copies over a surface, along a spiral, round a ring or packed in a volume; and a coat lays
icing, snow or slime over a surface with waves and drips.

For cutting, `sliceByPlane` cuts a closed mesh exactly and closes the cut face, holes and all, for a sliced fruit or a
cutaway. CSG gives union, subtract and intersect, with normals and uvs interpolated along the cut, so a drilled dimple
lights as a concave bowl. It is bake-time geometry: build the shape at load, register it, and no boolean runs during
play.

## Features

- **Twenty named primitives** — `box`, `roundedBox`, `sphere`, `cylinder`, `cone`, `capsule`, `torus`, `torusKnot`,
  `wedge`, `plane`, `quad`, `panel`, `disc`, `ring`, four platonic solids and more, each with its own settings.
- **Outline builders** — lathe, tube, shape and extrude, with ear-clipping for flat outlines.
- **Smooth forms** — `latheForm`, `sweepForm` (round, n-sided, star or custom sections, caps, twist, beads),
  `vesselForm` with contents and `leafForm`.
- **Deformers** — squash, lobes, taper, twist, noise and bend along a soup's height.
- **Scattering** — evenly over a surface, in rows by uv, along a spiral or a line, round a ring or packed in a sphere,
  cone, box, cylinder or bunch, then merged into one soup.
- **Coating** — a layer of given thickness over a surface, with waves, drips and a skirt where it ends.
- **Plane slicing** — an exact cut with the section closed from its own loops.
- **Polyhedral dice** — d4, d6, d8, d10, d12 and d20, chamfered, with each face's number in its uv.
- **CSG** — union, subtract and intersect, plus a fast `merge` for solids that do not touch.

## Good for

- **3D games with no art pipeline**, where furniture, props and pickups are built from rounded boxes, discs and
  lathes.
- **Board and dice games**, with real numbered dice and pieces turned on a lathe.
- **Food and cooking games** — sliced fruit, iced cakes with drips, glasses of juice filled to a level.
- **Stylised nature** — leaves, stems swept along curves and berries scattered in a bunch.
- **Architecture and level props** — windows cut out of walls, notches and engraving with CSG.
- **Packs and tools that generate meshes**, which can stand on the same builders.

## Make it yours

Every primitive takes its own optional settings, and `world3d.mesh` caches one mesh per option set, so a 12-sided
cylinder and a 64-sided one are two meshes and the same options are one. Your own builders join the catalogue with
`define`. Smooth forms come back at a real size, and `toUnitBox` fits one into a unit box when one mesh should serve
many sizes.

Two quite different uses: a dice game that registers `dieSoup(20, { chamfer: 0.04 })` once and textures the faces by
their uv numbers; and a dessert-shop game that lathes a cake, coats it with dripping icing, scatters sprinkles over the
top and slices it open with a plane, the cut face closed.

## A quick look

A lathed vase that serves every size, and a chamfered d20:

```ts
import { latheForm, toUnitBox, dieSoup } from '@phaser-ae/geometry-3d';
const vase = latheForm([[0, 0], [0.12, 0.02], [0.18, 0.2], [0.08, 0.38], [0.1, 0.42]], { around: 32 });
game.world3d.defineMesh('vase', toUnitBox(vase));        // one mesh for vases of any size
game.world3d.defineMesh('d20', dieSoup(20, { chamfer: 0.04 }));
```

## Works with

- `world-3d` — registers the soups as meshes and builds its own from these functions.
- `model-3d` — procedural models (a banana, a glass of juice, a character) as specs built on these forms; usually the
  easier route for a whole object.
- `core-3d` — includes this pack, so most 3D games have it already.
- `procgen` — the source of the Perlin noise the deformers and `gradientNoise` use.
- `model-files-3d` — for models made in a modelling program rather than in code.

## Good to know

- Builders return triangle soups, not indexed geometry: simple and fast to upload, but a sphere has more vertices
  than an indexed one would.
- `earClip` handles simple polygons, not holes or self-intersection; `sliceByPlane` closes holed sections itself.
- CSG is the classic BSP algorithm: right for clean, closed tools against a body, not a CAD kernel for
  self-intersecting meshes. Merge the tools and subtract once; many separate subtracts are slow.
- It is bake-time work: build at load, never per frame.

---

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