Also source effects are computed before occlusion/verb/HRTF plugins (and spatialization speakermapping).
Pre 4.18, the source effects are done post-distance-attenuation, but in 4.18, I seperated out volume attenuation due to all other things, and volume due to distance attenuation and run the audio through their source effects pre-distance attenuation. This is way more intuitive and should help you with your occlusion work.
These are all great videos and features man and I’m super impressed with the work. Making me proud. :')
As for the practical aspect of this, in my experience, in real games, ray traces can end up being very expensive CPU-wise. If you want to ship this in a game, you’ll want to think of ways of pruning out traces and doing simple versions for some audio, more-complex versions for others, etc. Like a priority/LOD system based on distance or sound priority. I kept my UE4 native occlusion solution to be as bare-bones as possible on purpose to keep the expense low. I also did it on an “Epic Friday” off-schedule and didn’t have a lot of time to put in a ton of work on features and bells n whistles.