3 ms·

Ah, convolution reverb. We've had it for a long time in DSP. Basically what you do is pop a balloon (create an "impulse" -- you can also clap your hands or use

Ah, convolution reverb. We've had it for a long time in DSP. Basically what you do is pop a balloon (create an "impulse" -- you can also clap your hands or use an electric arc) and record the echo. This gives you what's called the "impulse response" of the space. Reverb is really just thousands of echoes, and echoes are just the original sound delayed back to you. So what you can do is use the impulse response in a FIR filter, convolve it with the original signal, and you've recreated the same reverb with a different sound. This technique has been quite accessible to audio engineers (and mechanical engineers) for a few decades now. But you really only go out and sample impulse responses when you really need a very accurate model of the reverb. In most cases someone will just use a precanned impulse response.

willis936 6y ago
This is one area where hardware accelerated ray-tracing has me excited. I like the idea of walking sound sources to the observer. Unlike light, you need to account for the speed of sound through mediums, which adds an extra layer of cool imo. You also don't need to update at the audio sample rate, since most objects will not be moving very fast (unless you want trans sonic simulations, which would be exotic and cool). Forget all of the little hacks. Sound processing is cheap. In 2020 it is unnecessary to select from a set of pre-baked filters and applying them to some predefined volume (ie this room is echoey, this room is absorbant, etc.) This is one area where software has regressed then stagnated [0]. It doesn't make any sense, other than it wasn't prioritized. I think it's only a matter of time before engines go back and finally complete the audio simulation problem. 0. https://www.youtube.com/watch?v=cS_Fbueh7F4 https://www.youtube.com/watch?v=cS_Fbueh7F4
- bkanber 6y ago
  I suppose it's a matter of acceptable approximations and cost. If only 2% of players have a high quality surround sound system, and only half of those have a good ear, then you really only have 1% of users who can tell the difference between raytraced audio and the heuristic "hacks" that sound engineers have spent decades developing. So I don't know if audio raytracing will become mainstream in games anytime soon. But I also suppose that if one engine does it, others will follow suit. Same thing with this Unreal 5 demo. Most users would not be able to tell the difference between rendering 16B vs 8B triangles per frame.
  - willis936 6y ago
    You don't need a high quality sound system or a good ear to tell the difference though. You just need a pair of headphones and to be a human with hearing. Evolution has been at work for eons. Every human born is a powerful audio processing machine. I can't give you a rigorous proof or hand you a double blind test to try for yourself, so you'll have to accept an impasse or start going down a rabbit hole consisting of studies on pre-baked ray-traced FIR filters of known geometries and the audibility of group delay. I am convinced every human can hear the difference. Computation is cheap. There's no reason not to solve the problem.
    - bkanber 6y ago
      You should submit a patch to Godot, then! Force Unreal and others to implement it too.

willis936 6y ago

This is one area where hardware accelerated ray-tracing has me excited. I like the idea of walking sound sources to the observer. Unlike light, you need to account for the speed of sound through mediums, which adds an extra layer of cool imo. You also don't need to update at the audio sample rate, since most objects will not be moving very fast (unless you want trans sonic simulations, which would be exotic and cool). Forget all of the little hacks. Sound processing is cheap. In 2020 it is unnecessary to select from a set of pre-baked filters and applying them to some predefined volume (ie this room is echoey, this room is absorbant, etc.) This is one area where software has regressed then stagnated [0]. It doesn't make any sense, other than it wasn't prioritized. I think it's only a matter of time before engines go back and finally complete the audio simulation problem. 0. https://www.youtube.com/watch?v=cS_Fbueh7F4 https://www.youtube.com/watch?v=cS_Fbueh7F4

bkanber 6y ago
I suppose it's a matter of acceptable approximations and cost. If only 2% of players have a high quality surround sound system, and only half of those have a good ear, then you really only have 1% of users who can tell the difference between raytraced audio and the heuristic "hacks" that sound engineers have spent decades developing. So I don't know if audio raytracing will become mainstream in games anytime soon. But I also suppose that if one engine does it, others will follow suit. Same thing with this Unreal 5 demo. Most users would not be able to tell the difference between rendering 16B vs 8B triangles per frame.
- willis936 6y ago
  You don't need a high quality sound system or a good ear to tell the difference though. You just need a pair of headphones and to be a human with hearing. Evolution has been at work for eons. Every human born is a powerful audio processing machine. I can't give you a rigorous proof or hand you a double blind test to try for yourself, so you'll have to accept an impasse or start going down a rabbit hole consisting of studies on pre-baked ray-traced FIR filters of known geometries and the audibility of group delay. I am convinced every human can hear the difference. Computation is cheap. There's no reason not to solve the problem.
  - bkanber 6y ago
    You should submit a patch to Godot, then! Force Unreal and others to implement it too.