three
Version:
JavaScript 3D library
104 lines (67 loc) • 3 kB
JavaScript
( function () {
function createMeshesFromInstancedMesh( instancedMesh ) {
const group = new THREE.Group();
const count = instancedMesh.count;
const geometry = instancedMesh.geometry;
const material = instancedMesh.material;
for ( let i = 0; i < count; i ++ ) {
const mesh = new THREE.Mesh( geometry, material );
instancedMesh.getMatrixAt( i, mesh.matrix );
mesh.matrix.decompose( mesh.position, mesh.quaternion, mesh.scale );
group.add( mesh );
}
group.copy( instancedMesh );
group.updateMatrixWorld(); // ensure correct world matrices of meshes
return group;
}
function createMeshesFromMultiMaterialMesh( mesh ) {
if ( Array.isArray( mesh.material ) === false ) {
console.warn( 'THREE.SceneUtils.createMeshesFromMultiMaterialMesh(): The given mesh has no multiple materials.' );
return mesh;
}
const object = new THREE.Group();
object.copy( mesh ); // merge groups (which automatically sorts them)
const geometry = THREE.mergeGroups( mesh.geometry );
const index = geometry.index;
const groups = geometry.groups;
const attributeNames = Object.keys( geometry.attributes ); // create a mesh for each group by extracting the buffer data into a new geometry
for ( let i = 0; i < groups.length; i ++ ) {
const group = groups[ i ];
const start = group.start;
const end = start + group.count;
const newGeometry = new THREE.BufferGeometry();
const newMaterial = mesh.material[ group.materialIndex ]; // process all buffer attributes
for ( let j = 0; j < attributeNames.length; j ++ ) {
const name = attributeNames[ j ];
const attribute = geometry.attributes[ name ];
const itemSize = attribute.itemSize;
const newLength = group.count * itemSize;
const type = attribute.array.constructor;
const newArray = new type( newLength );
const newAttribute = new THREE.BufferAttribute( newArray, itemSize );
for ( let k = start, n = 0; k < end; k ++, n ++ ) {
const ind = index.getX( k );
if ( itemSize >= 1 ) newAttribute.setX( n, attribute.getX( ind ) );
if ( itemSize >= 2 ) newAttribute.setY( n, attribute.getY( ind ) );
if ( itemSize >= 3 ) newAttribute.setZ( n, attribute.getZ( ind ) );
if ( itemSize >= 4 ) newAttribute.setW( n, attribute.getW( ind ) );
}
newGeometry.setAttribute( name, newAttribute );
}
const newMesh = new THREE.Mesh( newGeometry, newMaterial );
object.add( newMesh );
}
return object;
}
function createMultiMaterialObject( geometry, materials ) {
const group = new THREE.Group();
for ( let i = 0, l = materials.length; i < l; i ++ ) {
group.add( new THREE.Mesh( geometry, materials[ i ] ) );
}
return group;
}
THREE.SceneUtils = {};
THREE.SceneUtils.createMeshesFromInstancedMesh = createMeshesFromInstancedMesh;
THREE.SceneUtils.createMeshesFromMultiMaterialMesh = createMeshesFromMultiMaterialMesh;
THREE.SceneUtils.createMultiMaterialObject = createMultiMaterialObject;
} )();