Inside3D tutorials.

Created By:	Malcolm Lim
eMail:	mlbl@botepidemic.com
Difficulty Scale:	Medium
Web Page:	http://www.botepidemic.com/udm/

Here's a tutorial that will enable the bot model to "yaw" like a real player, i.e : when an enemy is on a higher level on top of the bot, the gun model will point at the enemy instead of just pointing straight forward. This was once a feature that Steven Polge wanted to implement before he went to work for Epic.

Step 1 :
Open up the file ai.qc. Paste this function at the end of the file :

/*
===========
ChangePitch

CN_PATCH

Turns towards self.ideal_pitch at 6 degree
chunks.  Used by Eliminator Bot.

Sets the global variable current_pitch
============
*/

void() ChangePitch =
{
	local float             ideal, move;

	
	current_pitch = self.angles_x;
	ideal = self.ideal_pitch;
	
	// only allow movement to within 54 degrees
	if (ideal > 54)
	  ideal = 54;
	else if (ideal < -54)
	  ideal = -54;

	if (current_pitch == ideal)
		return;
	
	move = ideal - current_pitch;
		
	if (move > 0)
	{
		if (move > 6)
			move = 6;
	}
	else
	{
		if (move < -6 )
			move = -6;
	}

	current_pitch = current_pitch + move;

	self.angles_x = current_pitch;
};

Step 2 :
Open up the file botthink.qc. Go to the function BotPostThink. Put in these code right above that function :

// Code from Eliminator Bot by Cameron Newham
void() checkyaw =
{
  local vector los;
  local vector los_angles;
  local float  o_range;
  local float  missile_factor;
  local vector spotty_squid;  // adds a tiny random for stationary targets

local string st;

  o_range = vlen(self.enemy.origin - self.origin);

  if ((self.weapon == IT_ROCKET_LAUNCHER) ||
      (self.weapon == IT_NAILGUN) ||
      (self.weapon == IT_SUPER_NAILGUN))
    missile_factor = o_range / (1900 + random() * 700);  // add scatter
  else if (self.weapon == IT_GRENADE_LAUNCHER)
    missile_factor = o_range / (1000 + random() * 50);  // add scatter
  else
    missile_factor = 0;  //other weapons are instantaneous

  // apply a small randomiser of the distance is large
  if (o_range > 300)
    spotty_squid = ('9 9 8') * (random() - 0.5);
  else
    spotty_squid = '0 0 0';

    // Face bot towards the specified angles
    los = self.enemy.origin - self.origin + self.enemy.velocity*missile_factor
          + spotty_squid;

    los_angles = vectoangles (los);
    self.ideal_pitch = los_angles_x;
    if (self.ideal_pitch > 180)
      self.ideal_pitch = self.ideal_pitch - 360;  //stupid id mistake

    ChangePitch();
};

Step 3 :
Now all we need to do is make a call to the function so place this piece of code inside the BotPostThink function, below the "local float fraglimit;" :

checkyaw ();

There you go ! You're done , save the files and recompile. You'll only notice the bot model yaw when you're an observer, a good map to see this happen is on maps like dm4, dm6, etc. Have fun !