SKILL.md
$28
const mesh = new Mesh({
geometry,
texture,
roundPixels: false,
});
app.stage.addChild(mesh);
Every `Mesh` subclass takes a single options object. The base `Mesh` requires a `geometry`; subclasses (`MeshSimple`, `MeshPlane`, `MeshRope`, `PerspectiveMesh`) build the geometry internally and require a `texture` instead. See each variant's reference for the full field list.
## Variants
| Variant | Use when | Trade-offs | Reference |
| ----------------- | ----------------------------------------------------- | ------------------------------------------------------- | ---------------------------------------------------------------- |
| `Mesh` | Full control, custom geometry, custom shaders | You build the `MeshGeometry` yourself | [references/mesh.md](references/mesh.md) |
| `MeshSimple` | Quick textured shapes with per-frame vertex animation | Thin wrapper; auto-updates the vertex buffer | [references/mesh-simple.md](references/mesh-simple.md) |
| `MeshPlane` | Subdivided textured rectangle for distortion effects | Fixed topology; `verticesX`/`verticesY` control density | [references/mesh-plane.md](references/mesh-plane.md) |
| `MeshRope` | Texture following a polyline path | Bent at each point; needs many points for smooth curves | [references/mesh-rope.md](references/mesh-rope.md) |
| `PerspectiveMesh` | 2D plane with perspective corners | Not true 3D; UV-level perspective correction only | [references/mesh-perspective.md](references/mesh-perspective.md) |
## When to use what
- **"I need a textured quad"** → `Sprite` (see `pixijs-scene-sprite`), not a mesh. Meshes are for cases Sprite can't express.
- **"I need to deform a textured rectangle"** → `MeshPlane`. Set `verticesX`/`verticesY` for the desired smoothness.
- **"I need a rope or trail that follows points"** → `MeshRope`. Control thickness with `width`; use `textureScale: 0` to stretch or `> 0` to repeat.
- **"I need a tilted 2D card or floor"** → `PerspectiveMesh`. Pass four corner positions; not real 3D but good enough for 2.5D effects.
- **"I need per-frame animated vertices with a simple shape"** → `MeshSimple`. It handles the buffer-update dance for you.
- **"I need a custom shader or unusual geometry"** → Base `Mesh` with a hand-built `MeshGeometry`. See `pixijs-custom-rendering` for shader authoring.
- **"I need true 3D rendering"** → Use a dedicated 3D library. `PerspectiveMesh` simulates perspective at the UV level but has no depth buffer.
## Quick concepts
### MeshGeometry owns the vertex data
`MeshGeometry` holds the `positions`, `uvs`, `indices`, and `topology`. You can share one geometry across multiple `Mesh` instances; positions are reference-counted.
### Batching
A mesh batches (combines with other draw calls) only if it uses `MeshGeometry`, has no custom shader, no depth or culling state, and the `'auto'` rule (`batchMode = 'auto'` and ≤100 vertices). Custom shaders always render independently.
### Topology is on the geometry, not the mesh
`new MeshGeometry({ topology: 'triangle-strip' })`; topology is a geometry property. The default is `'triangle-list'`; set it explicitly if your data is organized differently.
### Extra knobs
- `new MeshGeometry({ shrinkBuffersToFit: true })` — trims GPU buffer storage to the actual vertex count on creation. Use it when feeding large, one-shot geometries.
- `Mesh.containsPoint(point)` — topology-aware hit test that walks the triangles. Works with any `MeshGeometry`, including custom layouts.
- `new Mesh({ geometry, state })` — pass a `State` object to control blend, depth, and culling. Batching is disabled automatically if depth or culling flags are set. Defaults to `State.for2d()` when omitted.
## Common Mistakes
### [HIGH] Using old `SimpleMesh` / `SimplePlane` / `SimpleRope` names
Wrong:
import { SimpleRope } from "pixi.js";
const rope = new SimpleRope(texture, points);
Correct:
import { MeshRope } from "pixi.js";
const rope = new MeshRope({ texture, points });
Renamed in v8: `SimpleMesh` → `MeshSimple`, `SimplePlane` → `MeshPlane`, `SimpleRope` → `MeshRope`. All switched to options-object constructors.
### [HIGH] Positional constructor args for MeshGeometry
Wrong:
const geom = new MeshGeometry(vertices, uvs, indices);
Correct:
const geom = new MeshGeometry({
positions: vertices,
uvs,
indices,
topology: "triangle-list",
});
v8 uses an options object. Note the property is `positions`, not `vertices`; the `vertices` name is only used by `MeshSimple`.
### [MEDIUM] Adding children to a mesh
Wrong:
mesh.addChild(otherMesh);
Correct:
const group = new Container();
group.addChild(mesh, otherMesh);