The <needle-engine> web-component comes with a nice collection of built-in attributes that can be used to modify the look and feel of the loaded scene without the need to add or edit the three.js scene directly.
The table below shows a list of the most important ones:

Attribute	Description
Loading
src	Path to one or multiple glTF or glb files. Supported types are string, string[] or a stringified array (, separated)
dracoDecoderPath	URL to the draco decoder
dracoDecoderType	draco decoder type. Options are wasm or js. See three.js documentation
ktx2DecoderPath	URL to the KTX2 decoder
Rendering
skybox-image	URL to a skybox image (background image)
environment-image	optional, URL to a environment image (environment light)
Interaction
autoplay	add or set to true to auto play animations e.g. <needle-engine autoplay
camera-controls	add or set to true to automatically add OrbitControls if no camera controls are found in the scene
auto-rotate	add to enable auto-rotate (only used with camera-controls)
Events
loadstart	Name of the function to call when loading starts. Note that the arguments are (ctx:Context, evt:Event). You can call evt.preventDefault() to hide the default loading overlay
progress	Name of the function to call when loading updates
loadfinished	Name of the function to call when loading finishes
Loading Display	Available options to change how the Needle Engine loading display looks. Use ?debugloadingrendering for easier editing
loading-style	Options are light or dark
loading-background-color	PRO — Change the loading background color (e.g. =#dd5500)
loading-text-color	PRO — Change the loading text color
loading-logo-src	PRO — Change the loading logo image
primary-color	PRO — Change the primary loading color
secondary-color	PRO — Change the secondary loading color
hide-loading-overlay	PRO — Do not show the loading overlay, added in Needle Engine > 3.17.1
Internal
hash	Used internally, is appended to the files being loaded to force an update (e.g. when the browser has cached a glb file). Should not be edited manually.

Examples

<!-- Setting the path to a custom glb to be loaded -->
<needle-engine src="path/to/your.glb"></needle-engine>

<!-- Overriding where the draco decoder is located -->
<needle-engine src="path/to/your.glb" dracoDecoderPath="path/to/draco/folder"></needle-engine>

Setting environment images, playing animation and automatic camera controls. See it live on stackblitz

<needle-engine
      camera-controls
      auto-rotate
      autoplay
      skybox-image="https://dl.polyhaven.org/file/ph-assets/HDRIs/hdr/1k/industrial_sunset_puresky_1k.hdr"
      environment-image="https://dl.polyhaven.org/file/ph-assets/HDRIs/hdr/1k/industrial_sunset_puresky_1k.hdr"
      src="https://raw.githubusercontent.com/KhronosGroup/glTF-Sample-Models/master/2.0/DamagedHelmet/glTF-Embedded/DamagedHelmet.gltf"
      >
      </needle-engine>

Receiving an event when the needle-engine context has finished loading:

<needle-engine loadfinished="onLoadFinished"> </needle-engine>
<script>
    function onLoadFinished() {
        console.log("Needle Engine has finished loading");
    }
</script>

Custom Loading Style (PRO)

You can easily modify how Needle Engine looks by setting the appropriate attributes on the <needle-engine> web component. Please see the table above for details.

See code on github