Switching Sounds for Fake Occlusion
Ambient and Procedural Sound Design
Beginning this little lesson at the waterfall again, we are looking at how the sound travels when we walk from outside of a cave and into it. Right now, there is sound bleeding from the waterfall into the cave far too much. I start with finding a box trigger and dragging that to the entrance of the cave. I adjust it to cover the entire entrance of the cave, so it guarantees that the player will walk through the trigger at any given angle. Following this, I go into the level editor and create an overlap node for the trigger box. Then I select the three sound actors I want to be faded out, and create reference nodes for each of these. I drag from one of the reference nodes, and find fade out in the search bar. I enter how much time I want to have the sounds fade out, and then connect the other two sounds to that same fade out node. All things considered, this is fairly simple. I always like how things are very intuitive in the editors and a lot of it is drag and drop. This is super helpful, especially as I continue to learn!
Now time to add the fade in for these sounds if we walk out of the cave! I drag from the audio component node and search for the fade in node. I connect all three audio components to the target in the fade in as well. I set the fade in duration and now I have to make sure the trigger box can accommodate both the fade in and fade out. We can do this by using a flip flop node! I attach both the fade out and the fade in to this flip flop node. Easy enough! Then this will toggle between the fade in and fade out, depending on if the player is walking in or out of the cave.
Then I moved onto the wind sound that is present inside the cave. It was initially set to auto activate but we want to make sure that this sound doesn’t bleed outside of the cave either. There is a spot where we can deselect this auto activation. I then go into the level editor again, and repeat the same process with the fade in node and fade out node. Though this time, I connect the fade in node to the fade out node for the outside sounds. Then I do the same process vice versa for the opposite. As the outside noise fades out, the cave noise fades in. The same goes for when I’m walking out of the cave! There are so many small details that we don’t normally think of but are necessary to take into consideration when designing sound for games!! Fascinating!
Finally, we want to make sure that not every character triggers this sound sequence. We only want the player character to be the one that triggers this sequence. In the level editor, I created a player character reference node. I then connected this and ‘other actor’ in the trigger box node to an equals node. This signifies that we are referring to this player character in connection to this trigger box. I created a branch node that connected to this equals node and the trigger box. I connected the ‘true’ section into the flip flop node. The ‘false’ node connects to nothing. Since we only want the player character to trigger this sequence, if the character that enters the cave does not satisfy the rule of being a player character, the sequence will not trigger.
