Fmod 2.02.15 snapshot bug (also present in 2.02.17)

Snapshots don’t work in 2.02.15. Well they do, but sometimes they don’t.

I can create all the snapshots I want, but there are certain groups it won’t affect, no matter what I do, while it will affect other groups.

This has happened on 2 different projects that both use 2.02.15. Also on 2.02.17
Has been checked by 3 different sound designers.

Make a new snapshot. Put it on a timeline. Set it to affect a group. Make sure that the sound is not routed to the group you are affecting with you snapshot.
Play the event with the snapshot on the timeline=nothing happens.

Found a solution:

Make a new snapshot. Lets call it “Snapshot_A”. Set the snapshot to affect a group called “Group1”.
Make a new event. Put in a random sound. Make a loop region. Put in the “Snapshot_A” on the timeline. Let’s call the event “SQUARE”. Route this sound to whatever group you want.
Observe that when you are playing “SQUARE”, nothing happens to the channel called “Group1”. (Something should happen, bug because of a bug, nothing happens).

Make a new event. Put in a random sound. Route it to “Group1”. Set a loop region on this event. Let’s call this event “TRIANGLE”.

Now play “TRIANGLE” and " “SQUARE” at the same time and observe that the snapshot is affecting “Group1” correctly

Basically it seems that you have to route audio through the channel that can’t be affected by the snapshot (because of a bug) at the same time as you are running an event that is triggering the snapshot.

EDIT: It is not a solution. As soon as I remove the sound “TRIANGLE” from “Group1”, the snapshot is no longer ducking group1.

Something weird is going on and the project is pretty much unusable as it is.


What you’re observing is expected behavior, and is the result of an optimization on FMOD’s part. If a bus is not active (i.e. there are currently no active event instances routed to it), then snapshots will not affect the bus in question. This should have no effect on audio playing into the bus - if there is audio playing into the bus, then the bus will be active, then snapshots will affect the bus.

What would be a bug is if the bus isn’t affected by the snapshot even when the bus is active. I have not been able to reproduce this on my end, but please test the following on your end:

  1. Create an event “Event 1” with a timeline, place a snapshot instrument on the timeline that triggers a snapshot
  2. Create an event “Event 2”
  3. Route Event 2 into a bus, and make sure Event 1 isn’t routed to the same bus
  4. Set the snapshot to affect the bus
  5. Open both events in the event editor by opening one event, then clicking the “+” tab button above the central event editor window, and opening the other event
  6. Play Event 1

You should observe that the bus that Event 2 is routed into is affected by the snapshot since there is an instance of Event 2 active (but not necessarily playing) in the event editor. If you close Event 2’s tab in the event editor, the snapshot should no longer affect the bus. If this isn’t the observed behavior, please let me know.

Can replicate, so working as intended. Did not know of this optimization feature. Thought it was a bug.

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