Make Your Own Soundscapes

http://naturesoundsfor.me/

This isn't necessarily 3d related, but film/animation related in general. This site is a sound generator where you can mix and match different sounds found in nature, and personalize your own audio file to use however you want. I know from experience that sometimes you don't have time or the means to record every sound that you need, and sites like freesound.org don't always have exactly what you want. Hope this comes in handy!