Currently, ModalRoutes created using showDialog or showGeneralDialog do not allow full customization of the underlying ModalBarrier.

It’s only possible to change the background color, however I’d like full control over the animated widget in order to build my own. For example, a customer requested to apply Gaussian blur to the barrier.

The current solution involves creating the barrier myself and not using the neat routing system.

So the same way that showGeneralRoute has a PageBuilder Parameter, it could gain a BarrierBuilder.