In previous demo (lesson about spot lights) there was a stair and you saw that our code that covers collisions against the terrain is good enough to our avatar goes up in the stair. Why?

Because the avatar sends rays continualy to redefine his position in the Y axis. Look at the figure. At moment 2 the point of contact changes up. So: the avatar jumps to a new position. Realy the avatar does not collide against the floor. His position is recalculed every loop-timestep to be just "flying" over the floor. Very funny :-)

But realy important in this lesson is that we will make a total review of all we have seeing in out tutorial until now, presenting the complete code of an standard/basic application. Is the 3dD Basic Kit, a group of code that you can use like a first step in all projects. Because we have in the kit:

• the creation of an avatar;
• how to move him;
• the instalation of the camera in the avatar's eyes;
• control of his collision against the terrain;
• control of his collision against walls; and general collision;

It's usual that, if you are making a 1st person world, you will need this things in your project.

The general schema of the 3dD Basic Kit is:

1 - We have first of all a SETUPSCRIPT where we declare the world and call two sub-scripts: avatarobj and cameraobj:

global myworld
global avatarobj, cameraobj 
on preparemovie me
 setupobjects
end

on setupobjects
 clearglobals 
 member("world").resetworld()
 myworld = member("world")
  
 avatarobj = new(member("avatarobj").script)
  
 cameraobj = new(member("cameraobj").script) 
  
end 

In the AVATAROBJ sub-script we define:

• the main loop (control) that is called by the timestep script -in the frame where is the world;
• the translation and rotation of the avatar using arrow keys;
• the collision of avatar against the terrain using the seekfloor method;
• the colision of the avatar against walls and other objects

 
property fwvect
property upvect  

property distanceforward 
property steer  
property ang, xvect,avatarheight  
global myworld 

on new me
  upvect = vector(0, 1,0)
  fwvect = vector(0,0,1)
  distanceforward = 0
  steer = 0
  myworld.model("avatar").visibility = #none
    
  --for collision
  xvect = vector(1,0,0)
  ang = 0 
  avatarheight = 40 
  --
  
  --for wall collision
  myworld.model("avatar").addmodifier(#collision)
  myworld.model("avatar").collision.enabled = true
  myworld.model("avatar").collision.resolve = true
  myworld.model("avatar").collision.mode = #mesh 

  myworld.model("logo").addmodifier(#collision)
  myworld.model("logo").collision.enabled = true
  myworld.model("logo").collision.resolve = true 
  myworld.model("logo").collision.mode = #mesh 
  return me
  
end


 
on control me
  
 
  --avatar movements
  if keypressed(126) then   
    acc = 0.025
  else
    acc = 0
  end if 
  
  if keypressed(123) then   
    turn = 2
    
  else
    if keypressed(124) then   
      turn = -2
      
    else
      turn = 0
    end if
  end if 
  
  distanceforward = distanceforward + acc - 0.015
  
  if distanceforward < 0 then distanceforward = 0  
  if keypressed(125) then  distanceforward = - 0.8
  if distanceforward > 0.8 then distanceforward = 0.8
  
  --rotation of the avatar
  steer = (steer + turn)*0.8
  if steer < -5.0 then steer = -5.0
  if steer > 5.0 then steer = 5.0  
  myworld.model("avatar").transform.rotate(myworld.model("avatar").worldposition, upvect, steer)
  
  --translation of the avatar 
  rotator = transform()
  rotator.rotate(vector(0,0,0), upvect, steer) 
  fwvect = rotator*fwvect
  movement = ( fwvect*distanceforward )
  myworld.model("avatar").translate(movement ,#world)
  
   
  -- puting the avatar in the floor using data returned by seekfloor method 
  floordetails = seekfloor("avatar", "land", "world", avatarheight, upvect) 
  
  ang = 0
  
  if floordetails[1] = 0 then
    myworld.model("avatar").translate(-movement ,#world)
  else
     
  if floordetails[2] <> 0 then
     xvect = floordetails[2]
     ang = floordetails[3] 
    end if
  end if  
  
  myworld.model("avatar").transform.rotate(myworld.model("avatar").worldposition, xvect, ang)
  
end

--seekfloor method
on seekfloor modelname, floorname, worldname, modelheight, directionvector
  flag = 0
  tiltangle = 0
  tiltvector = 0
  
  alist = myworld.modelsUnderRay(myworld.model(modelname).worldposition - directionvector*100  ,directionvector,5, #detailed)  
  
   repeat with i = 1 to count(alist)
   
    if alist[i].model.name contains floorname  then
      a = alist[i].isectposition
      av = vector(0,(-myworld.model(modelname).worldposition.y + alist[i].isectposition.y +modelheight ), 0)
      myworld.model(modelname).translate(av, #world)
      ay = -directionvector
      tiltangle = -ay.anglebetween(alist[i].isectnormal)
      tiltvector = alist[i].isectnormal.perpendicularto(ay)
      flag = 1
      
      exit repeat     
    end if
  end repeat
  
  return [flag, tiltvector, tiltangle]  
end

In the sub-script CAMERAOBJ we define:

• an auxiliar object (aux) to glue the camera to the avatar;
• another main loop - called also by timestep - to translation of the camera like the avatar.

property mycam   
property aux  
property cameraoffset  

global avatarobj,myworld

on new me
  
  aux = myworld.newmodel("aux")
  mycam = myworld.camera[1]
  
  aux.visibility = #none
  mycam.projectionangle = 75 -- read about this properties in previous lesson
  cameraoffset = [0.0001, -0.0003]
 
  return me  
end

on control me 
   
  aux.transform.interpolateto(myworld.model("avatar").getworldtransform(),  100.0)
  camvect = (avatarobj.upvect*cameraoffset[1]+ avatarobj.fwvect*cameraoffset[2])
  aux.translate(camvect, #world)
  
   aux.pointat(myworld.model("avatar").worldposition ) 
  lag = 100
   mycam.transform.interpolateto(aux.getworldtransform(), lag)  
end

In the TIMESTEP script installed in the frame where the world is

• we create the loop and we call the controls methods every loop-timestep;
• we execute other actions started by triggers.

global avatarobj, cameraobj, myworld, trigger
 
on prepareframe me
  control avatarobj
  control cameraobj
    
end 

on exitFrame me
  go the frame

end

To start an action trigerred we have sometimes the Macromedia standard behaviors: by example:

• one trigger behavior that detects the click ;
• one action behavior that jumps the movie to the marker whose name is trigger where we have an script that sets some flag.

We will talk about this soon.

The script TRIGGER (there are not included in the kit) could be:

global avatarobj

on exitFrame me
  avatarobj.flagd=1
  go to "play"
  
end

You need to understand very well this group of scripts that are the "soul" of the inteligence of all the 1st person worlds that you will make.

DOWNLOAD OF THE 3dD BASIC KIT

The 3dD Basic Kit is the basic scenery where you can make the exercices of our tutorial.

We have a basic 3ds max world: kitb.max that is only a floor with an auxiliary sphere to be used to put the spot-light to iluminate the logo.

The Director world is: kitb.dir. It has the four scripts that we are talking about:

• setupscript
• avatarobj
• cameraobj and
• timestep

Normaly you will put YOUR code in the avatarobj script using one of the two methods: new - for one-time execution code or control - for code inside the timestep-loop.

In our lessons we will use the 3dD Basic Kit like a pre-requirement for the exercices and make references to it.

To download the files right-click the links, saving the target in your PC:

This is the 3dD Basic Kit world - it's a real Director world. You can walk and go up-stairs:

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