Adding shadows to gltf loader function

Questions
1

Im buildig on a project with an unfamiliar gltf loader, and I want to add shadows to it. The loader is set up like this in a separate utils.js:

function loadResource(url) {
    const extension = url.split('.').pop();
    let loader;

    switch (extension) {
        case 'jpg':
            loader = new THREE.ImageLoader();
            break;
        case 'glb':
        case 'gltf':
            loader = new THREE.GLTFLoader();
            break;
        default:
            return Promise.reject(new Error(`unknown resource type [${extension}]`));
    }

    return new Promise((resolve, reject) => {
        const onLoad = (resource) => resolve(resource);
        const onProgress = () => {};
        const onError = (e) => {
            console.error('Failed to load resource: ' + e.target.src);
            reject(e);
        };

        loader.load(url, onLoad, onProgress, onError);
        
    });

and the main.js is using an async:

(async function init() {
    utils.loadResource('model/SPACEBOX.jpg').then((cubeTexture) => {
        const skyBox = new THREE.CubeTexture(utils.sliceCubeTexture(cubeTexture));
        skyBox.needsUpdate = true;
        scene.background = skyBox;
    });

    const [wheelGLTF, chassisGLTF, terrainGLB, baseGLB] = await Promise.all([
        utils.loadResource('model/lwheel.gltf'),
        utils.loadResource('model/car.gltf'),
        utils.loadResource('model/floor.glb'),
        utils.loadResource('model/building.glb'),
    ]);
    
    const terrain = terrainGLB.scene;

    scene.add(terrain);

    const wheel = wheelGLTF.scene;
    const chassis = chassisGLTF.scene;
    const base = baseGLB.scene;
  ///  base.castShadow = true <failed attempt
    scene.add(base)

Loading the models like this seems really good but how do I add a shadow to this kind of setup? Cheers

2

maybe a stupid question, but do you have set an object to receive the casted shadow?
something like terrain.receiveShadow = true;

3

Hey, yes I have set true and cast shadow true on the building.