Ambient sound radii and room brush sizes

R Soul on 26/5/2013 at 14:50

Not for the first time, I had a problem where an ambient sound was being cut off as I stepped from its room brush to an adjoining one. In the past I would just make the first room brush bigger, so the sound would fade out normally before I got to the boundary. I had a similar problem today, and I decided to see if could work out the cause. It turns out to be quite simple.

For an ambient sound to be able to travel from one room brush to another, it has to be able to reach the centre of either of them, or both.

My roombrushes were quite tall, but fairly narrow in order to match the terrain. That moved the centre too far from the sound while placing a room brush boundary well within the ambient sound's radius. So, small radii and large room brushes are not a great combination. You could use a large radius with the NoSharpCurve flag, or keep room brushes small enough for the sound to reach the centre.

It's fortunate that it doesn't seem to affect other schemas, such as collisions, noisemaker sounds, or AI speech.

LarryG on 26/5/2013 at 15:28

Great detective work! Knowing this will help a lot.

Notesthes on 26/5/2013 at 18:20

Regarding ambient sound radii: I do not understand, what kind of radius is used. Is the radius a sphere? A cube?
If anyone knows that, I would like to know this. If I know, how this radius is meant, I can plan better and do not have to experiment each time.

Quote Posted by R Soul

So, small radii and large room brushes are not a great combination.

But I can use one small Ambient Sound within a large roombrush without caring about the centres, if I only want to have the Ambient Sound within this one roombrush, or not? But what if I want to have a small area at the border of two roombrushes? Do I have to create an extra roombrush for a good sound? (Sorry, I really have no experience with this.)

john9818a on 26/11/2014 at 06:57

Quote Posted by R Soul

It's fortunate that it doesn't seem to affect other schemas, such as collisions, noisemaker sounds, or AI speech.

Those other schemas can be heard a great distance away. If you have ever played with headphones you should notice how far away they can be heard even if ever so quiet. :)

Random_Taffer on 26/11/2014 at 12:58

Great find! I always have the trouble with this and now I know why.

DrK on 26/11/2014 at 15:34

Nice find, that'll come handy. Even though I managed to find a way around this issue I still have a few ambients being cut off from one room to another. I never expected the center of roombrushes to be this important for sound propagation.

Comes to think of it, when I build the room database sometimes the monolog tells me some of the roombrushes have their center into a solid brush or something, and yet I made sure to have all their center located in an air brush. It seems kinda random too, sometimes it builds fine, sometimes I have a massive list of yellow lines appearing in monolog. Now, sound propagation works perfectly fine so far, but should I be worried about this at some point ?

R Soul on 26/11/2014 at 17:09

There's another error to watch out for. When to room brushes intersect, the centre of that intersection must not be in solid.

Exaple of an L shaped room with three solid pillars:

Inline Image:

http://i912.photobucket.com/albums/ac326/rsoulinternet/Dromed/intersection_zps539d8a86.gif

You can split the roombrushes or you can cheat by moving/resizing them to shift the intersection:

Inline Image:

http://i912.photobucket.com/albums/ac326/rsoulinternet/Dromed/intersection2_zpse940f453.gif
(Left roombrush moved south and depth increased).
(edit: Corrected image link)

By zooming in you can see that the intersection is just outside the cylinder:

Inline Image:

http://i912.photobucket.com/albums/ac326/rsoulinternet/Dromed/intersection3_zps8a9d444e.gif

I remember reading an official Dromed document saying it's not necessarily an error (hence the 'warning' in monolog), but you should check that you really want that intersection. I think it's best to eliminate them so you don't get into the habit of ignoring all warnings.

DrK on 26/11/2014 at 23:19

Hmm thanks, I guess that's the problem I have.
Architecture in my FM is way too complex for me to solve this. I'm pretty sure if I fix an intersection here, another one will appear there. So as long as it works, I'll keep it that way. Thanks for the info though ;)

Caradavin on 26/11/2014 at 23:32

I needed this bit of info - thanks!

Xorak on 29/11/2014 at 03:14

Thankyou. I have always wondered what that meant. I went back to some of my older missions and was able to start clearing some of those warnings just to test it out. Nice to know going forward. Keep that monolog looking clean and tight.