Audio materials let you set objects to a specific material type so that reverberation (sound waves bouncing off those objects) are treated differently. For example, singing in the shower is quite echoey compared to singing in other rooms, in part because most bathrooms have tile, metal, and other very reflective surfaces that have different properties than a living room with reflection-dampening rugs.
Material type also affects footstep sounds, as heard in this video graciously shared by creator Nobby, which shows his "FOXIS Island" (a work in progress as of April 20, 2017). Notice how he's set different objects to different audio materials, so as his avatar walks over them, the sound changes to mimic what you'd expect on grass, wood, or tile.
List of audio materials
As of the March 2, 2017 release, there are varied preset material types that model their real-world, physical counterparts. This is the order in which the materials appear in the UI, and we intend to continue expanding and organizing this list:
- silent - Use this if you want no avatar footsteps to be heard when walking over an object. No reverb.
- generic - A generic "wood" footstep sound. Normal reverb.
- wood - Sounds like wood. Long reverb.
- bushes - Relatively long rustling with overlapping release tails. No reverb.
- brick - Hard, gritty surface sound. Long reverb.
- concrete - Hard, gritty surface sound. Long reverb.
- plaster - Hard, gritty surface sound. Medium reverb.
- rock -Hard, gritty surface sound. Short reverb.
- ceramic - Hard, clean surface sound. Long, harsh reverb.
- glass - Hard, clean surface sound. Long, harsh reverb.
- metal - Hard, clean surface sound. Short reverb.
- carpet - Sounds similar to stepping on a box of crisp rice cereal. No reverb.
- gravel - Sounds like stepping on gravel. No reverb.
- water - Makes appropriate splashing noises. Useful to enhance the illusion of walking in a liquid.
- dirt - Sounds like stepping on dirt. Medium reverb.
- grass - Crisp, gentle crunchy sounds. No reverb.
- sand - Sounds like stepping on sand. No reverb.
Some types share the same footstep foley yet have different reverb properties, while others have their own unique footstep sounds. For example, even though "gravel", "dirt", and "sand" are all made of small bits of earth in the physical world, they have distinct sonic identities. You don't need to be literal about matching a material name to what the walkable surface is meant to be — go with what sounds right. For example, "dirt" might be used for a grassy field.
The two extremes are "carpet" and "ceramic". Here's a comparison of those two. (note that as of R7, the "Compute Scene Reverb off" example is not accurate, because reverb has been removed from non-baked experiences):
These examples were created by placing an avatar in first-person view, in front of an audio emitter inside of a big box set to the different audio materials. Note that due to the variability of Sansar spawn points and avatar navigation, this isn't an exact A/B comparison, but it should effectively show you the difference.
You can also hear the comparison files in their entirety. The recorded audio is Sansar's raw output, no compression or further processing has been applied:
- Audio Materials Comparison - Carpet.wav
- Audio Materials Comparison - Ceramic.wav
- Audio Materials Comparison - Source.wav - upload this into Sansar for your own testing!
Setting audio material for an object
Make sure Compute Scene Reverb (casually known as bake reverb), which is at the bottom of the Scene Settings, is on in your experience.
- Click an object.
- Click the Properties button.
- Next to AudioMaterial, click the dropdown menu and choose a material.
As the old adage goes, if it sounds good, it is good — so please experiment and let us know what you've created!
As with other Sansar audio features where spatial audio can be a key contributor to immersion, we recommend you test your own experience with a good pair of headphones, and, if possible, in VR mode.