Reversing the angles of an entity

[DusterdooSmock]

Alright, is there a way to reverse the angles of an entity?
IE: projectile flies at a wall, when it hits the wall, its direction is reversed and it fies back towards where it came from?

[Spike]

newvel = oldvel - (normal * ((oldvel*normal) * 2));

will reflect a direction/velocity vector by a normal.
you can bounce an angle by using makevectors/vectoangles to convert that angle into a regular vector and back, though you'd need extensions to retain the roll.

[necros]

Spike's entirely code is correct. however, if you want to literally bounce "back towards where it came from", then that's simply a matter of inverting the .velocity vector. (ie: self.velocity = self.velocity * -1).

[DusterdooSmock]

Alright, thanks guys.

[Cobalt]

Yes, & the darkplaces bouncemissile is suppose to pretty much do this too. After I tested it, it does work but you still need to add in some -velocity_z on your own (in the entitys touch pointer) if its a projectile such as nails....else they bounce forever with a small chance of ever stopping. Another check to see if they are in water, slime or lava too...I decided to make them a movetype_toss if they are now in a liquid....lava burns em up......

[DusterdooSmock]

Ok, now I would like to expand upon this a little bit...



Lets say the projectile flies at wall "A" from location 1.
How would I alter the angles of the projectile so that after it hits wall "A", it flies towards wall "B", and then when it hits wall "B", it changes its angles again so that it flies towards location 2?
And, vice versa; if the projectile flew at wall "B" from location 2, it would alter its angles so that it flies at wall "A", then when it hits wall "A", it alters its angles again so that it flies towards location 1.
Sort of like a "ricochet" effect...

[r00k]

ent.movetype |= MOVETYPE_BOUNCE ?

[DusterdooSmock]

ent.movetype |= MOVETYPE_BOUNCE ?

But that won't alter the angles so that the projectile flies in the path that I described...

[Nahuel]

ent.movetype |= MOVETYPE_BOUNCE ?

But that won't alter the angles so that the projectile flies in the path that I described...

if you look in old mods you will find the "pulse rifle"

Code: Select all

// Modified for the Ultimate Weapons Mod by Andy Brennan.
// =======================================================================


// rebound the pulse spike
void() pulse_rebound =
{
   // want the spike to hurt owner now, use maker field to keep
   // track of whose spike it is

   if (self.state == 0)  // if it hasn't bounced yet
   {
      self.owner = world;
      self.state = 1;
   }

   self.velocity = normalize(self.velocity) * 1000;
   self.movetype = MOVETYPE_FLYMISSILE;
   self.angles = vectoangles(self.velocity);
   self.think = SUB_Remove;
   self.nextthink = self.ltime;
};

void() pulse_touch =
{
   local float rand;

   if (other.solid == SOLID_TRIGGER)
      return; // trigger field, do nothing

   if (pointcontents(self.origin) == CONTENT_SKY)
   {
      remove(self);
      return;
   }

   if (self.velocity == '0 0 0')
   {
      remove (self);
      return;
   }

   if (other.takedamage)
   {
// ==========================================================             
// BLOOD FIX
// ==========================================================             
            spawn_touchblood (15);
      else
      {
         // play a ricochet sound
         rand = random() * 100;
         if (rand < 33)
            sound (self, CHAN_AUTO, "ric_1.wav", 1, ATTN_NORM);
         else if (rand < 66)
            sound (self, CHAN_AUTO, "ric_2.wav", 1, ATTN_NORM);
         else
            sound (self, CHAN_AUTO, "ric_3.wav", 1, ATTN_NORM);

         WriteByte (MSG_BROADCAST, SVC_TEMPENTITY);
         WriteByte (MSG_BROADCAST, TE_SUPERSPIKE);
         WriteCoord (MSG_BROADCAST, self.origin_x);
         WriteCoord (MSG_BROADCAST, self.origin_y);
         WriteCoord (MSG_BROADCAST, self.origin_z);

         // rebound
         self.movetype = MOVETYPE_BOUNCE;
         self.think = pulse_rebound;
         self.ltime = self.nextthink;
         self.nextthink = time + 0.1;
         return;
      }
      rand = 15 + random() * 10;
      T_Damage (other, self, self.maker, rand);
      remove (self);
      return;
   }
   else
   {
      // play a ricochet sound
      rand = random() * 100;
      if (rand < 33)
         sound (self, CHAN_AUTO, "ric_1.wav", 1, ATTN_NORM);
      else if (rand < 66)
         sound (self, CHAN_AUTO, "ric_2.wav", 1, ATTN_NORM);
      else
         sound (self, CHAN_AUTO, "ric_3.wav", 1, ATTN_NORM);

      WriteByte (MSG_BROADCAST, SVC_TEMPENTITY);
      WriteByte (MSG_BROADCAST, TE_SUPERSPIKE);
      WriteCoord (MSG_BROADCAST, self.origin_x);
      WriteCoord (MSG_BROADCAST, self.origin_y);
      WriteCoord (MSG_BROADCAST, self.origin_z);

      // rebound
      self.movetype = MOVETYPE_BOUNCE;
      self.think = pulse_rebound;
      self.ltime = self.nextthink;
      self.nextthink = time + 0.1;
      return;
   }
};

void(float ox) W_FirePulseSpikes =
{
   local vector dir;
   local entity pulse;
   
   
   makevectors (self.v_angle);
   sound (self, CHAN_WEAPON, "pulse_1.wav", 1, ATTN_NORM);
   self.ammo_nails = self.ammo_nails - 2;
   self.currentammo = self.ammo_nails = self.ammo_nails - 2;

   self.punchangle_x = -2;

   dir = aim (self, 1000);

   pulse = spawn ();
   pulse.owner = self;
   pulse.maker = self;
   pulse.classname = "pulse";
   pulse.movetype = MOVETYPE_FLYMISSILE;
   pulse.solid = SOLID_BBOX;

   // use the state field to determine if it has bounced yet
   pulse.state = 0;
   
   pulse.angles = vectoangles(dir);
   pulse.velocity = dir * 1000;
   
   pulse.touch = pulse_touch;
   pulse.think = SUB_Remove;
   pulse.nextthink = time + 3;   // time limit
   
   setmodel (pulse, "progs/nail.mdl");
   setsize (pulse, VEC_ORIGIN, VEC_ORIGIN);               


};


[DusterdooSmock]

I'll give it a shot. Thanks.

EDIT:
It works like what I needed. Thank you.