Project Dalian v0.5.9-alpha

Project Dalian v0.5.9-alpha

Multiplayer netcode overhaul — snapshot interpolation + input replication

Symptoms in v0.5.8: second player still moved very slowly (host could lap them); remote soldiers looked orange/tan, small in the distance, with guns sticking out of shoulders and deformed arms.

Root cause: v0.5.8 added velocity and vehicle replication but still used exponential position smoothing (wrong model for fast movement). Remote facing used velocity instead of look yaw; team colour tints distorted appearance.

Fixes (industry-standard listen-server netcode):

Phase 1 — Movement sync

• Snapshot interpolation (Gaffer model): 64-entry timestamped ring buffer per player; render ~100 ms in the past by lerping two known snapshots
• Dead reckoning for short gaps (pos + vel × age, capped at 250 ms)
• Hard snap if render position drifts >2 m from authoritative state
• Immediate relay: host rebroadcasts on every client MSG_STATE / MSG_INPUT (not only host frame)
• Fixed 60 Hz snapshot timer decoupled from host render FPS

Phase 2 — Visual fixes

• Measured velocity from position delta each send (not just desired_velocity)
• Remote facing = look yaw (matches local third-person; fixes gun-through-shoulder)
• Neutral soldier tint (no orange/blue team wash on remotes)
• Interpolated anim_time from snapshot buffer

Phase 3 — Input replication foundation

• New NetInput + MSG_INPUT wire message (seq, move, yaw/pitch, buttons)
• Sent every frame alongside state; stored server-side per player
• Wire format v3 adds input_seq (backward compatible with v2)

Both players must use this build.

Includes all v0.5.8 fixes

• Vehicle transform replication, spawn-locked unoccupied vehicles
• v0.5.7 viewport fix, v0.5.6 UI/kill feed polish