arScale property
Controls the scaling behavior in AR mode. Set to "fixed" to disable scaling of the model, which sets it to always be at 100% scale. Defaults to "auto" which allows the model to be resized by pinch.
You many use the ArScale enum to set this attribute.
<model-viewer>
official document: https://modelviewer.dev/docs/#entrydocs-augmentedreality-attributes-arScale
Implementation
final ArScale? arScale;