Source 2 exposes baked spatial audio
Valve’s Source 2 update reveals Steam Audio baking with probe grids, baked reverb parameters (ray/bounce counts, IR duration), occlusion and clustering — tech that maps directly onto advanced spatial audio workflows like Dolby Atmos. (x.com) That means custom-map designers can now control baked ambisonics and reverb in ways that will translate to immersive game audio mixes and home-theater demos. (x.com)
The Steam Audio repository contains a baked_reflection_data schema and matching baker code (reflection_baker.cpp), showing baked reflection data is serialized and stored by the SDK. (github.com) Steam Audio's release notes for SDK 4.7.0 added new API objects (IPLEnergyField, IPLImpulseResponse, IPLReconstructor) and functions that let callers convert raw simulation results into impulse responses and directly extract baked data. (github.com) Unity integration docs expose the same probe-based workflow used in the repo: Steam Audio requires creating sound probes and probe batches, and provides Reverb Data Point, Baked Listener and Baked Source components for precomputing reflections and reverb at probe positions. (github.com) Header and plugin files in the codebase include explicit fields for impulse-response duration and Ambisonic order (e.g., duration and ambisonic-order members in phonon/phonon.h and the IPLImpulseResponse API), indicating baked assets store IR length and ambisonic channel data. (github.com) Recent Steam Audio releases add editor-level baking controls and middleware integrations—release notes list menu options to “bake all pathing, reverb, etc. in the current scene” and a Wwise plugin for pipeline integration—giving map makers UI-driven bake tooling and export paths. (github.com) Source 2’s Workshop Tools already ship with precompute pipelines for lighting (VRAD/VRAD3 and lightprobe volumes) and Hammer 5.x is included in Workshop Tools DLC across Source 2 games, establishing the same editor context where probe-based audio baking could be surfaced to mappers. (developer.valvesoftware.com)
