Scene
The Scene section is everything that is not the product: how it is lit, what is behind it, how the customer moves the camera, and what they look at while the model loads.
It makes more difference than people expect. The same model can look like a catalogue photograph or like a grey lump depending on nothing but the lighting and background.
The scene is already fitted for you
You do not need to set this up from nothing. When you load the first model into a new project, Composer measures it and configures the scene around it: the camera position, target and clipping planes, two directional lights with shadows, the skybox, and the background. The settings it picks are tuned for the size of your model and for performance, and for most products the result is good immediately.
This happens once, only while the scene has nothing configured yet. As soon as anything in this section has been set, Composer stops touching it, because from that point on the settings are yours.
Re-fitting later
There is a button called Fit scene to model at the top of the section, and it runs that same calculation again on demand.
It is worth pressing when the scene has changed size substantially: you have added several more models, or a much larger or much smaller one, or removed the model everything was framed around. Camera distance, shadow coverage and clipping are all derived from the overall size of what is loaded, so a scene that has grown a lot is usually framed for the product it no longer contains.
Fit scene to model replaces the camera settings, deletes and rebuilds the directional lights, and resets the skybox and the background type. Anything you tuned in those four areas is gone, and there is no undo.
If you have spent time on your lighting or on camera limits and you are happy with them, do not press it. Adjust the camera by hand instead, and add a light rather than re-fitting. If you want to try it anyway, take a project file from Files first so you can come back.
Camera
The camera orbits around a point, which is the natural way to look at a product. You set where it starts and what it points at, and you can limit how far the customer may orbit, tilt or zoom.
Limits are worth setting. Without them a customer can end up underneath the product or so far away it is a speck, and neither shows off what you make. Constraining the camera to the angles the product looks good from is one of the cheapest improvements you can make.
Clicking into the camera position or target fields brings up handles in the 3D view so you can drag the camera into place rather than typing numbers.
Lighting
Directional lights behave like the sun, casting parallel light from an angle. You add as many as you need, and set the direction, colour, intensity and whether each one casts shadows.
Two or three lights is usually right. One strong light gives shape, a weaker one from another angle stops the shadow side going black, and a third from behind can lift the product away from the background.
As with the camera, focusing a light's direction field gives you a handle in the 3D view. Dragging it is the fast way to work, because you can see what the light does as you move it.
Background
Four kinds. A solid colour on every plan, and linear gradient, radial gradient and image on Standard and Pro.
A plain background in a colour close to your store's is usually the right choice, since it keeps attention on the product. Gradients help when a product is the same tone as a flat background and disappears into it.
Skybox
The skybox is what the product reflects. Even when you cannot see it, it decides whether metal looks like metal and whether gloss looks like gloss, so it matters most for polished, chrome or glass products.
You can pick one of the built-in environments or supply your own as an .hdr or .env file. There is a converter built in: give it an .hdr and it produces the .env format, which is smaller and loads faster. Use the converter rather than shipping raw .hdr files to your customers.
Hide skybox keeps the reflections while showing your chosen background instead of the environment image, which is usually what you want on a product page.
Environment intensity controls how strongly it lights the scene, and blur softens reflections, which makes a hard environment look less distracting.
Loading screen
Your customer sees this before they see the product, so it is worth two minutes.
You can set a logo, a progress bar, and a line of text with its colour and size. Putting your own logo here makes the wait feel like part of your store rather than a blank pause.
Keep in mind that the best loading screen is a short one. If yours is on screen long enough to read, the model is probably too heavy. See What to Expect.
Rendering engine
A choice between WebGL and WebGPU.
WebGL is the default and runs everywhere. WebGPU is newer and faster on the browsers and devices that support it. If you are unsure, leave it on WebGL, since compatibility matters more than frame rate on a product page.
Switching between them rebuilds the 3D view, which takes a moment. That is expected and your settings are kept.
Beneath it is a right-handed coordinate system toggle. Leave it as it is unless a model comes in mirrored or rotated in a way nothing else explains.
Parameter bindings
These connect a customer's choice directly to a number in the scene.
Say you have a slider for width. A binding can drive the actual scale of a model from that slider, so the product physically stretches as they drag, without any script involved. You can bind to a whole model, to a single part inside a glTF file, or to a light.
This is the simplest way to make a product respond continuously rather than in fixed steps, and it covers a lot of ground before you need Scripting.
Scene rotation
A slow automatic turn of everything in the scene. Good for a hero product that should look alive while a customer reads the page, and easy to overdo. If your configurator has many options to click through, a moving product can make it harder to use.