Incorrect bounding box using the threejs scene

[pesa2000]

Hi Mark, im trying to setup a mesh to put under the bottom of a splat.

The best way to achieve that is to calculate the lower bottom using the bounding box, whatever method i try i cant retrieve the correct coordinates for the box.

Any suggestions?

Thank you in advance

[Patrick-van-Halm-360Fabriek]

We have a solution for this, with the latest update 0.4.5 @mkkellogg introduced the SplatMesh.computeBoundingBox() method. To access this you need to access the viewer. Some psuedo code would be:

const viewer = new GaussianSplats3D.DropInViewer({
  ...
});

viewer.addSplatScene(...);

const bounds = viewer.splatMesh.computeBoundingBox();
const size = bounds.getSize(new THREE.Vector3()); // Y being the full height of the bounds
const center = bounds.getCenter(new THREE.Vector3());

const lowerBottom = new THREE.Vector3(center.x, center.y - (size.y / 2), center.z); // This is the lowest bounds in the center of the object

[pesa2000]

Hi @Patrick-van-Halm-360Fabriek, thank you very much, im actually trying this right now.

const bounds = this.viewer.splatMesh.computeBoundingBox();
const boxHelper = new THREE.Box3Helper(bounds, 0xff0000);
this.scene.add(boxHelper);

Using the code below to render the bounds i get this as a result.

Maybe is it related to the scale of the splat?

[pesa2000]

Update: passing true as the first param helps since is going to apply the same transformations applied to the scene.

The result is still a little bit off.

[Patrick-van-Halm-360Fabriek]

I don't know if the Box3Helper does fully work with the splat Bounds. Maybe @mkkellogg could join in with the specific information about it.