trigger footsteps on embedded object

yvanvds · 09-05-2013 09:33 PM

Hello agian.

I'm working on footsteps now. Basically I play a sound file when animateStepOccured is called, so that part is easy. But to decide on the type of sound, i look at the material below the user. Also very easy:

PHP Code:

Game::World.hmMaterial(p.xz())->user_type; 

I even found some code to play a different sound when the character walks through shallow water.

But what I cannot find out: if the character walks on an object, like a bridge or a wall, how to find out the material type?

That kind of objects is typically embedded in the terrain. Having custom classes for every building, bridge and other object just because I want to know what kind of footstep to play doesn't seem like the right solution. On the other hand, playing a 'wooden' footstep if on a bridge and a more 'soggy' one when walking below it seems not too far fetched, or does it?

So far i tried:
1. doing a physics ray below the character. But I don't get the objects that are imbedded with the terrain, is that correct?
2. Going through all embedded objects in the current Area and see if there is a Cuts(posBelowActor, embeddedObjectShape). I never get a hit though. I tried the same with terrain_objs instead of embed_objs, but still no hits.

I have included the code for 2. below, for reference. Still, I'd think an easy method to find out the material you walk on, even if it is a terrain object, could be useful for about any game. I hope i've just overlooked something.

Regards,

yvan

PHP Code:

void character::character::animateStepOccured() {
  Vec p = pos();
  p.y = Game::World.hmHeight(p.xz());
  Int type = MUT_DEFAULT;
  if(Game::World.waterUnder(p)) {
    // this means we're just below water level, but still walking
    type = MUT_WATER;
  } else {
    
    p = ctrl.actor.pos();
    p.y -= ctrl.radius() + 0.05;
    if(p.y < Game::World.hmHeight(p.xz(), true)) {
      // get material from the terrain we're walking on
      type = Game::World.hmMaterial(p.xz())->user_type;
    } else {
      // char is somewhere above terrain, but walking
      // so check for object right below character
      Int type = MUT_VOID;   
      Game::Area * area = Game::World.areaActive(Game::World.worldToArea(pos().xz()));
      if (area != NULL) {
        REPA(area->data()->embed_objs) {
          if(Cuts(p, area->data()->embed_objs[i].actor.shape(false))) {
            const MeshPtr m = area->data()->embed_objs[i].mesh();
            REPAD(j, m->parts) {
              if (Equal(m->parts[j].name, "material")) {
                type =  m->parts[j].material()->user_type;
                break;
              }
            }
            break;
          }
        }
      }
    }
    switch(type) {
      case MUT_WATER: {
        _stepsWater[Random(7)].play().pos(YSEVec(T.pos())).speed(RandomF(0.95, 1.05));
        break;
      }  
      case MUT_STONE:
      case MUT_ROAD: {
        _stepsStone[Random(5)].play().pos(YSEVec(T.pos())).speed(RandomF(0.95, 1.05));
        break;
      }
      case MUT_PLANT: {
        _stepsGrass[Random(5)].play().pos(YSEVec(T.pos())).speed(RandomF(0.95, 1.05));
        break;
      }
      case MUT_METAL: {
        _stepsMetal[Random(4)].play().pos(YSEVec(T.pos())).speed(RandomF(0.95, 1.05));
        break;
      }
      case MUT_WOOD: {
        _stepsWood[Random(4)].play().pos(YSEVec(T.pos())).speed(RandomF(0.95, 1.05));
        break;
      }
      case MUT_SNOW:
      case MUT_ICE: {
        _stepsSnow[Random(5)].play().pos(YSEVec(T.pos())).speed(RandomF(0.95, 1.05));
        break;
      }
      case MUT_VOID: break;
      default: {
        _stepsWoodland[Random(8)].play().pos(YSEVec(T.pos())).speed(RandomF(0.95, 1.05));
        break;
      }
    }
  }
} 

yvanvds · 09-06-2013 10:10 PM

So it works like this:

PHP Code:

void character::character::animateStepOccured() {
  Vec p = pos();
  p.y = Game::World.hmHeight(p.xz());
  Int type = MUT_DEFAULT;
  if(Game::World.waterUnder(p)) {
    // this means we're just below water level, but still walking
    type = MUT_WATER;
  } else { 
    p = ctrl.actor.pos();
    p.y -= ctrl.radius() + 0.01;
    if(p.y < Game::World.hmHeight(p.xz(), true)) {
      // get material from the terrain we're walking on
      type = Game::World.hmMaterial(p.xz())->user_type;
    } else {
      // char is somewhere above terrain, but walking
      // first, check if the previous found object is still below
      if(Inside(p, previousObject)) {
        type = lastType;
      } else {
        // see if we're on another object
        type = MUT_WOOD; // default is wood   
        Game::Area * area = Game::World.areaActive(Game::World.worldToArea(pos().xz()));
        if (area != NULL) {
          REPA(area->data()->embed_objs) {
            if (area->data()->embed_objs[i].phys == NULL) continue;
            previousObject = area->data()->embed_objs[i].phys->box;
            if(Inside(p, previousObject)) {
              const MeshPtr m = area->data()->embed_objs[i].mesh();
              if(m->parts.elms() == 1) {
                type = m->parts[0].material()->user_type;
                lastType = type;
              } else {
                REPAD(j, m->parts) {
                  if (Equal(m->parts[j].name, "step")) {
                    type =  m->parts[j].material()->user_type;
                    lastType = type;
                    break;
                  }
                }
              }
              break;
            }
          }
        }
      }
    }
    switch(type) {
      case MUT_WATER: {
      // now play footstep sound according to material 

If you're using EE2.0 i think you have use terrain_objs instead of embed_objs.

There's still one problem left to solve: if an object is too big, it will not be included in embed_objs. Instead mesh and physics are loaded into the area meshgroup and physbody objects. I have not figured out how they relate to each other.

Cheers,

yvan

Pixel Perfect · 09-21-2013 08:29 AM

Thanks again yvanvds. I'm just getting round to coding sound support for the first time and this is a useful illustration. wink

I'm starting with lip synced NPC speech (tied into my animation module) but overall sound support including footsteps will be next.

yvanvds · 09-21-2013 11:48 AM

Good luck with that!

You'll be amazed how much a few sounds contribute to the overal feel of your game world. After walking around in a silent world for more than a year, i was impressed by the difference after adding environment sounds and footsteps.

Pixel Perfect · 09-21-2013 11:56 AM

Agreed, I added a lot when developing with my previous game engine and it really does breath life into a game and noticeably adds to the feeling of immersion.

gdalex · 09-21-2013 04:17 PM

This seems awesome. I'll try that quickly, thanks for sharing, Yvands smile

Related question: how did you implement local sounds in your game ?
For example the sound of a forge when you approach a blacksmith's house ?

trigger footsteps on embedded object
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