Set Frequency Channelgroups & Slowmo effect

Hi. I struggle to understand what exactly are channelgroups. My goal is to achieve a slowmo effect affecting the playback rate of certain bus or vca within fmod, scaling it on the Unity playback rate. I saw that there is a setFrequency function but I don’t understand how to assign it to the buses I want to control. It seems like I have to create a channelgroup but I don’t know how I can assign the desired bus to this channel group, because I dont really understand what are channelgroup. Can someone shed light on these concepts ?

A channel group is a group of channels which is similar to a bus, with channels being the various low level inputs that make up events and other buses. Usually it’s a bit too complicated to try and manipulate a buses channel group directly like this. Instead I would recommend utilizing snapshots and the bus’ pitch property to perform this. It would simply require you to start and stop a snapshot in the same manner you do an event.

You can see an example of this happening by looking at the Examples project provided with your FMOD Studio installation and checking the “Slow-Motion” snapshot and the SFX bus in the mixer.

You can read more about snapshots in our documentation:

https://www.fmod.com/resources/documentation-studio?version=2.02&page=mixing.html#snapshots-and-the-tracks-view

1 Like

Hi Richard. Thank you for your answer. I was afraid that the pitch being limited to -24 st wouldn’t allow me to get the effet slow enough but it wasn’t the case and I ended up with a good result. Could you give some example of situation where you would need to manipulate low level channel ?

There are certain functionalities that are available for ChannelGroups that aren’t available for buses. You can see a list of all available functions for ChannelGroups here:

https://www.fmod.com/resources/documentation-api?version=2.02&page=core-api-channelgroup.html

It is hard to give an example of needing to use a ChannelGroup over a bus, but I suppose a usage might be to get callbacks that aren’t available with buses.

1 Like