How to restrict the camera to an entity’s bounding box?

In order to set boundaries to the user navigation (for instance, staying inside a room), you can restrict the camera’s position to a bounding box.

The idea is:

get the Bounding Box (ie: AABB) of the bounding entity (eg: the scene_ref to the room).
on each frame, check if the camera is within the bounding box
if the camera is outside, travel towards the center of the bounding box until the camera is within the bounds.

export const boundCameraToEntity = async (entityId: string) => {
    const entity = (await SDK3DVerse.engineAPI.findEntitiesByEUID(entityId))[0];

    if (!entity) {
        console.error("Entity not found");
        return;
    }

    const viewport = SDK3DVerse.engineAPI.cameraAPI.getViewports()[0];
    const local_aabb = entity.getComponent("local_aabb");
    const { min, max, center } = SDK3DVerse.utils.computeAABB(local_aabb, entity.getGlobalMatrix());

    let isTraveling = false;

    SDK3DVerse.notifier.on("onFramePreRender", async () => {
        const globalTransform = viewport.getTransform();
        const position = globalTransform.position;

        let isOutsideAABB = false;

        for (let i = 0; i < 3; i++) {
            if (position[i] < min[i] || position[i] > max[i]) {
                isOutsideAABB = true;
            }
        }

        if (isOutsideAABB && !isTraveling) {
            isTraveling = true;
            SDK3DVerse.disableInputs();
            viewport.travel(center, globalTransform.orientation, 10);
        } else if (!isOutsideAABB && isTraveling) {
            viewport.stopTravel();
            SDK3DVerse.enableInputs();
            isTraveling = false;
        }
    });
};

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