  Globally-constrained classical fields provide a unexplored framework for
modeling quantum phenomena, including apparent particle-like behavior. By
allowing controllable constraints on unknown past fields, these models are
retrocausal but not retro-signaling, respecting the conventional block universe
viewpoint of classical spacetime. Several example models are developed that
resolve the most essential problems with using classical electromagnetic fields
to explain single-photon phenomena. These models share some similarities with
Stochastic Electrodynamics, but without the infinite background energy problem,
and with a clear path to explaining entanglement phenomena. Intriguingly, the
average intermediate field intensities share a surprising connection with
quantum "weak values", even in the single-photon limit. This new class of
models is hoped to guide further research into spacetime-based accounts of weak
values, entanglement, and other quantum phenomena.
