How to get the bounding sphere for a whole scene in three.js? I may try to get the bounding sphere for each object and compute the resulting union of them, but I think there may be a more straight forward method.
There are different methods to get a boundingSphere of multiple objects dynamically. You can get first the bounding box of all of them, and then create a sphere of that bounding box... here is a sample fiddle I have shaped on boundingSphere of a boundingBox.
Basically you put all the geometries into a Group
, you get the Box3
of the group, and then you do getBoundingSphere
from the Box3 and position at the center. Code in the fiddle would be this.
let g = new THREE.Group();
scene.add(g);
for (let i = 0; i < 5; i++) {
// geometry
var geometry = new THREE.BoxGeometry(20, 20, 20);
// material
var material = new THREE.MeshToonMaterial({
color: 0xff0000,
opacity: 0.7,
});
// mesh
mesh = new THREE.Mesh(geometry, material);
mesh.position.set(100 * Math.random(), 100 * Math.random(), 100 * Math.random());
g.add(mesh);
}
//g.updateWorldMatrix(true);
var gridHelper = new THREE.GridHelper(400, 40, 0x0000ff, 0x808080);
gridHelper.position.y = 0;
gridHelper.position.x = 0;
scene.add(gridHelper);
let bbox = new THREE.Box3().setFromObject(g);
let helper = new THREE.Box3Helper(bbox, new THREE.Color(0, 255, 0));
scene.add(helper);
const center = new THREE.Vector3();
bbox.getCenter(center);
let bsphere = bbox.getBoundingSphere(new THREE.Sphere(center));
let m = new THREE.MeshStandardMaterial({
color: 0xffffff,
opacity: 0.3,
transparent: true
});
var geometry = new THREE.SphereGeometry(bsphere.radius, 32, 32);
let sMesh = new THREE.Mesh(geometry, m);
scene.add(sMesh);
sMesh.position.copy(center);
EDITED: If you want to include in the boundingSphere for the scene including the lights (which could get you a huge sphere), just start from let bbox = new THREE.Box3().setFromObject(scene)