spread property
In terms of Neumorphic Shadows, the argument spread is responsible for determining how wide an area the effect covers and how blurry the shadows appear.
The default is defaultSpread, 7.5.
The method buildLinearGradient ignores this property as it corresponds to Shadows, a visual element missing from a LinearGradient. These gradients may be combined with shadows in other situations, where spread will then be considered.
Implementation
final double spread;