FMOD Occlusion

Hi,
We are currently developing a game in Unreal engine with FMOD plugin integration and FMOD Studio GUI for handling all audio in the game.
We managed to implement sound occlusion with line tracing, but we are not quite satisfied with the results, as we wanted a more realistic feel of it (the sound to be heard if you are near enough, although there is an obstacle between the player and sound). As I understood there is FMOD::Geometry low-level class that should do exactly this, but it only works with low-level sounds, not FMOD Studio events. Furthermore, it supposed to be enabled to work with FMOD Studio events from the version 1.09 !? Are there any updates on this topic? Is there any tutorial or example how to set up our occlusion with this class?

Secondly, we tried to implement Steam Audio with FMOD Studio and Unreal, and we managed to install the plugin int FMOD Studio, but we cannot find the way to make it work with the events played from the engine (there is no sound at all, UNreal and FMOD console show no error). IS this even possible? Is there any tutorial as we didn’t manage to find any?

INFO: Unreal Engine 4.17.3, FMOD Studio 1.10.01

Thank you for your help
Best, Dino

The LowLevel Geometry only works with the LowLevel, not Studio.

UE4’s system is a more deluxe solution, that even comes built in to the engine ready to go.

There are a couple ways we have setup the integration to use Occlusion.
The first is using the User Property of an event. By adding “Occlusion:1” to the User properties of an event, you can then drive the Occlusion in UE4 using the FMODAudioComponent settings.

The second way is to use a parameter named “Occlusion”, the introduction of presets in 1.10 makes this much easier to use, which allows you to use FMOD Studio to control the parameter effects.

https://fmod.com/resources/documentation-api?page=content/generated/engine_ue4/occlusion.html#/

We have plans to overhaul and improve this system in the future.
Along the lines of: using specific parameters (eg. OcclusionVolume, OcclusionLPF) on events to pass the information directly to Studio instead of the current system.

As for Steam Audio, make sure you have added the plugin dll to the correct Pltaform Binary folder in the FMOD UE4 plugin, then add the name to the list of plugins in the Editor settings.
https://fmod.com/resources/documentation-api?page=content/generated/engine_ue4/plugins.html#/

1 Like

Hi,
Thank you for helping me out, I was missing the plugin dll in the Platform Binary folder.
Now my events are playing but when I try to enable occlusion (whatever option except occlusion-off) in the Steam audio spatializer in the effects of the event the sound is completely off? What am I missing?

Best, Dino

Also can you provide me some guidelines, tutorials or links for FMOD::Geometry class usage as I cannot find any!?

Using the Unity-FMOD-Steam-Audio plugin as a reference, it looks like there is a lot more to it than just a small dll to include. That dll will allow you to use the sounds created in FMOD Studio using the plugin, but to get occlusion to work requires a lot more work. In the Unity plugin they basically created their own raycasting system.

We don’t actually develop the plugin, that is up to Valve. I’m not sure if they are working on a plugin for UE4 or not, you would be best off putting that question to them yourself.

https://valvesoftware.github.io/steam-audio/downloads.html
The geometry mentioned in the Steam docs is not the FMOD::Geometry.

We don’t have any tutorials for using the Geometry at the moment, we only really have the class docs:
https://fmod.com/resources/documentation-api?page=content/generated/common/lowlevel_introduction.html#3d-polygon-based-geometry-occlusion
https://fmod.com/resources/documentation-api?page=content/generated/FMOD_Geometry_AddPolygon.html#/

Thanks for your time you help me a lot.