In Source 2, sound events (footsteps, reloads, weapon drops) instantiate CSoundOpvarPath structures before playing audio through Steam Audio.

By reading the recent sound events ring buffer from soundsystem.dll:

1. Extract 3D position (x, y, z) and event string (player.footstep.concrete).
2. Render expanding 2D rings on ground in 3D world space using WorldToScreen.
3. Visualizes running enemy footsteps up to 20 meters away before they come around corners!

Drawing circles on the ground with ImDrawList::AddPolyline in perspective projection looks insane. Great release.

Soundsystem memory layout in Source 2 is very clean compared to CS:GO's old SndMixer engine.