Interface BoundDecoder

Transforms a 2D boundary field into a 3D scalar field. Converts boundary information into an implicit scalar field.

This is the core transformation step that turns a boundary description into a holographic volume.

The returned scalar field follows an implicit surface convention:

• value > 0 : inside the object
• value = 0 : on the implicit surface
• value < 0 : outside the object

Must generate a zero crossing inside the sampled volume,

- for the intended bondary field target.

All decoder implementations must satisfy this convention.