three-projected-material

Three.js Material which lets you do Texture Projection on a 3d Model.

Installation

After having installed three.js, install it from npm with:

npm install three-projected-material

yarn add three-projected-material

You can also use it from the CDN, just make sure to use the three.js import map:

<script type="importmap">
  {
    "imports": {
      "three": "https://unpkg.com/three/build/three.module.js"
    }
  }
</script>
<script type="module">
  import ProjectedMaterial from 'https://unpkg.com/three-projected-material/build/ProjectedMaterial.module.js'
  // ...
</script>

Getting started

You can import it like this

import ProjectedMaterial from 'three-projected-material'

or, if you're using CommonJS

const ProjectedMaterial = require('three-projected-material').default

Then, you can use it like this:

const geometry = new THREE.BoxGeometry(1, 1, 1)
const material = new ProjectedMaterial({
  camera, // the camera that acts as a projector
  texture, // the texture being projected
  textureScale: 0.8, // scale down the texture a bit
  textureOffset: new THREE.Vector2(0.1, 0.1), // you can translate the texture if you want
  cover: true, // enable background-size: cover behaviour, by default it's like background-size: contain
  color: '#ccc', // the color of the object if it's not projected on
  roughness: 0.3, // you can pass any other option that belongs to MeshPhysicalMaterial
})
const box = new THREE.Mesh(geometry, material)
webgl.scene.add(box)

// move the mesh any way you want!
box.rotation.y = -Math.PI / 4

// and when you're ready project the texture on the box!
material.project(box)

ProjectedMaterial also supports instanced meshes via three.js' InstancedMesh, and even multiple projections. Check out the examples below for a detailed guide!

Examples

API Reference

new ProjectedMaterial({ camera, texture, ...others })

Create a new material to later use for a mesh.

Option	Default	Description
`camera`		The PerspectiveCamera the texture will be projected from.
`texture`		The Texture being projected.
`textureScale`	1	Make the texture bigger or smaller.
`textureOffset`	`new THREE.Vector2()`	Offset the texture in a x or y direction. The unit system goes from 0 to 1, from the bottom left corner to the top right corner of the projector camera frustum.
`cover`	false	Wheter the texture should act like `background-size: cover` on the projector frustum. By default it works like `background-size: contain`.
`backgroundOpacity`	1	The opacity of the part of the mesh which is not covered by the projected texture. You can set this to 0 if you don't want the non-projected part of the mesh to be shown.
`...options`		Other options you pass to any three.js material like `color`, `opacity`, `envMap` and so on. The material is built from a MeshPhysicalMaterial, so you can pass any property of that material and of its parent MeshStandardMaterial.

These properties are exposed as properties of the material, so you can change them later.

For example, to update the material texture and change its scale:

material.texture = newTexture
material.textureScale = 0.8

material.project(mesh)

Project the texture from the camera on the mesh. With this method we "take a snaphot" of the current mesh and camera position in space. The After calling this method, you can move the mesh or the camera freely.

Option	Description
`mesh`	The mesh that has a `ProjectedMaterial` as material.

allocateProjectionData(geometry, instancesCount)

Allocate the data that will be used when projecting on an InstancedMesh. Use this on the geometry that will be used in pair with a ProjectedMaterial when initializing InstancedMesh.

This needs to be called before .projectInstanceAt().

Option	Description
`geometry`	The geometry that will be passed to the `InstancedMesh`.
`instancesCount`	The number of instances, the same that will be passed to the `InstancedMesh`.

material.projectInstanceAt(index, instancedMesh, matrix)

Do the projection for an InstancedMesh. Don't forget to call updateMatrix() like you do before calling InstancedMesh.setMatrixAt().

To do projection an an instanced mesh, the geometry needs to be prepared with allocateProjectionData() beforehand.

dummy.updateMatrix()
projectInstanceAt(i, instancedMesh, dummy.matrix)

Link to the full example about instancing.

Option	Description
`index`	The index of the instanced element to project.
`instancedMesh`	The InstancedMesh with a projected material.
`matrix`	The `matrix` of the dummy you used to position the instanced mesh element. Be sure to call `.updateMatrix()` beforehand.

marcofugaro/three-projected-material