whats up with the sound entry in addMaterialMapping?

#1 I think this is already obsolete. See art/terrains/Test/materials.cs for a pretty cool explanation about what you should use.

#2 mm, I see nothing about sound there...

#3 It's in the template project - from
art/terrains/Test/materials.cs:

new Material( TerrainSoft )
{
   FootstepSoundId = 0;       // Soft footstep sound defined on player datablock.
   ImpactSoundId = 0;         // Soft impact sound.
   ShowDust = false;          // Don't show dust particles (footpuffs, hover trails, etc.)
   ShowFootprints = true;     // But show footprints.
};

new Material( TerrainDirtGrass : TerrainSoft )
{
   MapTo = "dirt_grass";
};

This specifies to play sound 0 when we step on this material (in this case dirt_grass). But what is sound 0?

from player.cs (DefaultPlayerData), we see the sounds defined:

FootSoftSound        = FootLightSoftSound;
   FootHardSound        = FootLightHardSound;
   FootMetalSound       = FootLightMetalSound;
   FootSnowSound        = FootLightSnowSound;
   FootShallowSound     = FootLightShallowSplashSound;
   FootWadingSound      = FootLightWadingSound;
   FootUnderwaterSound  = FootLightUnderwaterSound;

But we need to look in player.h to see what is sound 0:

enum Sounds {
      FootSoft,
      FootHard,
      FootMetal,
      FootSnow,
      FootShallowSplash,
      FootWading,
      FootUnderWater,
      FootBubbles,
      MoveBubbles,
      WaterBreath,
      ImpactSoft,
      ImpactHard,
      ImpactMetal,
      ImpactSnow,
      ImpactWaterEasy,
      ImpactWaterMedium,
      ImpactWaterHard,
      ExitWater,
      MaxSounds
   };
   SFXProfile* sound[MaxSounds];

So in this case, sound 0 is FootSoft sound, which is defined as FootLightSoftSound in the datablock. And the definition for that is (in the same file):

datablock SFXProfile(FootLightSoftSound)
{
   filename    = "art/sound/footstep_soft";
   description = AudioClosest3d;
   preload = true;
};

So, whenever the player steps on dirt_grass, we should hear the footstep_soft sound.

#4 Edit: Jaimi beat me to it :)

// This is an example of how to map terrain blend tiles to material
// instances within Torque.  None of these materials will be used
// for rendering, but they will be used by the collision detection
// code and thus play their part in defining interaction behavior
// when coming into contact with these materials.

new Material( TerrainSoft )
{
   FootstepSoundId = 0;       // Soft footstep sound defined on player datablock.
   ImpactSoundId = 0;         // Soft impact sound.
   ShowDust = false;          // Don't show dust particles (footpuffs, hover trails, etc.)
   ShowFootprints = true;     // But show footprints.
};
new Material( TerrainHard )
{
   FootstepSoundId = 1;       // Hard footstep sound defined on player datablock.
   ImpactSoundId = 1;         // Hard impact sound.
   ShowDust = true;           // Show dust particles.
   ShowFootprints = true;     // And show footprints.
};

// If you want custom sound effects for footstep and impact sounds,
// use the 'customFootstepSound' and 'customImpactSound' material properties
// that allow referencing SFXProfiles and will override the Id-based definitions.

// ...

new Material( TerrainDirtGrass : TerrainSoft )
{
   MapTo = "dirt_grass";
};

new Material( TerrainRocks : TerrainHard )
{
   MapTo = "rocks1";
   
   // Choose a grey-ish particle color for the dust emitters.
   EffectColor[ 0 ] = "0.5 0.5 0.5 1.0";
   EffectColor[ 1 ] = "1.0 1.0 1.0 0.0";
};

So you will need to define the sounds themselves on the player datablock, and set this if the given material (which maps to the same texture as the diffuse of your terrain material) will trigger the player's different footstep or impact sounds, most notably:

FootSoftSound        = FootLightSoftSound;
   FootHardSound        = FootLightHardSound;
   FootMetalSound       = FootLightMetalSound;
   FootSnowSound        = FootLightSnowSound;
   FootShallowSound     = FootLightShallowSplashSound;
   FootWadingSound      = FootLightWadingSound;
   FootUnderwaterSound  = FootLightUnderwaterSound;

   FootBubblesSound     = FootLightBubblesSound;
   movingBubblesSound   = ArmorMoveBubblesSound;
   waterBreathSound     = WaterBreathMaleSound;

   impactSoftSound      = ImpactLightSoftSound;
   impactHardSound      = ImpactLightHardSound;
   impactMetalSound     = ImpactLightMetalSound;
   impactSnowSound      = ImpactLightSnowSound;

   impactWaterEasy      = ImpactLightWaterEasySound;
   impactWaterMedium    = ImpactLightWaterMediumSound;
   impactWaterHard      = ImpactLightWaterHardSound;

Here comes the obscure part. Checking player.cpp:

addField("FootSoftSound",       TypeSFXProfilePtr, Offset(sound[FootSoft],          PlayerData));
   addField("FootHardSound",       TypeSFXProfilePtr, Offset(sound[FootHard],          PlayerData));
   addField("FootMetalSound",      TypeSFXProfilePtr, Offset(sound[FootMetal],         PlayerData));
   addField("FootSnowSound",       TypeSFXProfilePtr, Offset(sound[FootSnow],          PlayerData));
   addField("FootShallowSound",    TypeSFXProfilePtr, Offset(sound[FootShallowSplash], PlayerData));
   addField("FootWadingSound",     TypeSFXProfilePtr, Offset(sound[FootWading],        PlayerData));
   addField("FootUnderwaterSound", TypeSFXProfilePtr, Offset(sound[FootUnderWater],    PlayerData));
   addField("FootBubblesSound",    TypeSFXProfilePtr, Offset(sound[FootBubbles],       PlayerData));
   addField("movingBubblesSound",   TypeSFXProfilePtr, Offset(sound[MoveBubbles],        PlayerData));
   addField("waterBreathSound",     TypeSFXProfilePtr, Offset(sound[WaterBreath],        PlayerData));

and player.h:

/// Zounds!
   enum Sounds {
      FootSoft,
      FootHard,
      FootMetal,
      FootSnow,
      FootShallowSplash,
      FootWading,
      FootUnderWater,
      FootBubbles,
      MoveBubbles,
      WaterBreath,
      ImpactSoft,
      ImpactHard,
      ImpactMetal,
      ImpactSnow,
      ImpactWaterEasy,
      ImpactWaterMedium,
      ImpactWaterHard,
      ExitWater,
      MaxSounds
   };

What that points to is that FootSoftSound will have an id of 0, FootHardSound 1, FootMetalSound 2, and so on..

If you wanted to have a metal thread plate material, you could set it up like this:

FootstepSoundId = 2;       // Footstep on metal sound
   ImpactSoundId = 12;        // Impact on metal sound (yes, it doesn't start from 0, its in the same enum)
   ShowDust = false;          // no puffs on a metal thread plate
   ShowFootprints = false;    // nor footprints

I hope that clears stuff up a bit. ;)

#5 lovely, thanks guys, that clears it up nicely.

#6 Somehow that explanatory faux material file got put into the "art/terrains/envpack" directory in the FPS Kit.... hmm, I should have caught that before now ;D

I'm almost certain that you wouldn't include the water sounds when you setup your materials, only the four (hard, soft, metal, snow (0, 1, 2, 3)) footstep sounds and/or the "impact" sounds. Water should be handling it's sounds separately -- unless that's changed too.

#7
BTW, you really don't need to fiddle with the number-based sound identification from Player if you don't want to. I just kept this because it was already in there and it made sense to support it.

However, there is also the "customFootstepSound" and "customImpactSound" properties on materials. These reference SFXProfiles directly and will take precedence over the ID-based versions.

On the other hand, after figuring out what number does what, it may be easier to just go with it.

Also, the initial confusion around addMaterialMapping was because this function name was simply reused in TGEA for something completely different. addMaterialMapping() in TGEA/T3D has nothing to do with addMaterialMapping() in TGE.

Water sound effects are also handled in the player code but are not based on materials since there isn't really a collision going on there. It's a bunch of tests for water coverage.