 # Trouble getting the true bounds of a nested scene graph

While working with giant maps (Rotating world map data into flat plane) I have a 3 deep set of Transform nodes wrapping a set of meshes. I need to know the exact bounds of the meshes contents so I can “wrap” all the map tiles with a border object (think 3d version of a 9-slice image).

Tried to do it with https://www.babylonjs-playground.com/#9JG4AA#1 but the bounds is too large. Sure this has to do with the rotation and scaling. But I need the water tight bounds.

Tried

``````    let xformMin = mapMax;
let xformMax = mapMin;

mapMeshes.forEach((m, i) => {
const mat4 = m
.computeWorldMatrix(true)
.clone()
.invert();
const bb = m.getBoundingInfo().boundingBox;

const newMin = Vector3.TransformCoordinates(bb.minimumWorld, mat4);
xformMin.minimizeInPlace(newMin);
const newMax = Vector3.TransformCoordinates(bb.maximumWorld, mat4);
xformMax.maximizeInPlace(newMax);

console.log(i, newMax.subtract(newMin));
});
console.log(xformMin, xformMax, xformMax.subtract(xformMin));
``````

With similar results.

The meshes are a combination of Mesh and InstanceMesh. Is there a way to “bake” down a set of transform of the verts on a hierarchy and get the accurate bounds?

Maybe you want to use `transformNode.getHierarchyBoundingVectors()` ?

Yep tried that too, why I include the playground example https://www.babylonjs-playground.com/#9JG4AA#1

oh sorry I misread Then I’m not sure what you call “accurate” bounds? This ones are pretty accurate but they are axis aligned. Maybe you want object bounding boxes?