Projectile System Collison

[bochek]

I am having a little bit of trouble getting my collision system to work on my guns... here is some code it is very self explanitory..


This gets called by the draw loop.

Code: Select all

void checkCollision()
{

    
     if(Bullet)
     {
        if(Character)
        {
            if (characterIsAlive)
            {
                if(Character->getTransformedBoundingBox().intersectsWithBox(Bullet->getTransformedBoundingBox()))
                {
                   Character->setVisible(false);                                                                                          
                   characterIsAlive = false;
             
                }
            }
        }
     }
}

and this is the function that gets called when you shoot

Code: Select all

void shoot(core::vector3df position, core::vector3df rotation, core::vector3df endPosition)
{  
   if(intCount >0)
   {
        BulletMesh = smgr->getMesh("media/Weapons/BFG/bullet/bullet.3ds");
        Bullet = smgr->addAnimatedMeshSceneNode(BulletMesh);
        
        core::vector3df addRotation;
        addRotation = core::vector3df(90,0,0);
        
        core::vector3df end = (endPosition - position);
        end.normalize();
        end = position + (end * camera->getFarValue());
        
    
        
        Bullet ->setScale(core::vector3df(20,20,20));
        Bullet ->setPosition(position);
        Bullet ->setRotation(rotation + addRotation);
        Bullet->setMaterialFlag(video::EMF_LIGHTING, false);
        
        f32 length = (f32)(end - position).getLength();
        const f32 speed = 10.0f;
        u32 time = (u32)(length / speed);
        
        anim = smgr->createFlyStraightAnimator(position, end, time);
        Bullet->addAnimator(anim);	
        anim->drop();
        
        anim = smgr->createDeleteAnimator(time+5);
        Bullet->addAnimator(anim);
        anim->drop();

        
        for(int x = 0; x < 10; x++)
        {
            
            anim = smgr ->createCollisionResponseAnimator(ObjectSelector[x], Bullet, core::vector3df(1,1,1),
            core::vector3df(0,0,0),
            core::vector3df(0,50,0));
            Bullet->addAnimator(anim);
            anim -> drop();
        }
        
            anim = smgr ->createCollisionResponseAnimator(mapSelector, Bullet, core::vector3df(1,1,1),
            core::vector3df(0,0,0),
            core::vector3df(0,0,0));
            Bullet->addAnimator(anim);
            anim -> drop();
            

           
    }
    
}

It only crashes if the first shot misses the character.

Any help would be appreciated

Thanks,
Bochek

[Guest]

BUMP^^

anyone.... school projects due tomorow! need help quick please!

Bochek

[pfo]

Does the delete animator delete the object? If so, then your variable Bullet still points to that location in memory, where the Bullet no longer exists if the delete animator clears it. This is whats causing the crash. When the bullet hits, you are probably deleting it and setting its reference to NULL, like you should, but you need to take into account what happens when the delete animator clears the bullet.

[sudi]

How funny i had the exact same problem with my fps game...actually my code looked alot like yours.....anyways i droped the project cause i couldn't find the error...than i started the bomberman game and its almost done there is just this little network problem....Anyways what i wanted to say is that i learned a better way of doing it.

class CBullet
{
protected:
ISceneNodeAnimator* anim;
ISceneNode* node;
IAnimatedMesh* mesh;
vector3df startposition;

int type;
int range;
int speed;
bool alive;
ISceneManager* smgr;

public:
bool getLife()
{
return alive;
}
CBullet()
{
alive = true;
smgr = device->getSceneManager();
}
CBullet(int mtype, vector3df position, vector3df orientation,int mrange, int mspeed)
{
type = mtype;
range = mrange;
speed = mspeed;
alive = true;
startposition = position;
smgr = device->getSceneManager();

if(mesh = smgr->getMesh("YOUR MODEL"))
{
node = smgr->addAnimatedMeshSceneNode(mesh);
}
if(node)
{
node->setPosition(position);
node->setRotation(orientation);

anim = smgr ->createCollisionResponseAnimator(metaselector, node, core::vector3df(1,1,1),
core::vector3df(0,0,0),
core::vector3df(0,50,0));
node->addAnimator(anim);
anim -> drop();
}
}
void kill()
{
//Don't how the animator is called correctly
if(node)
{
anim = smgr->createDeleteAnimator(1);
node->addAnimator(anim);
anim->drop();
}
alive = false;
}
void render(std::vector *players)
{
node->setPosition(node->getAbsolutePosition()+orientation*speed);
if(node->getAbsolutePosition().getDistanceFrom(startposition) == range || node->getAbsolutePosition().getDistanceFrom(startposition) > range)
{
kill();
}else
{
if(players)
{
for(int i;i<players->size();i++)
{
if(players->Character->getTransformedBoundingBox().intersectsWithBox(node->getTransformedBoundingBox()))
{
switch(type)
{
case 1:
//do something with character
break;
case 2:
//do something with character
break;
case 3:
//do something with character
break;
}
}
}
kill();
}
}
}
};

//needed variables
std::vector<CBullet> bullets;
std::vector<YOUR PLAYERCALSS> players;

int i;
vector<CBullet>::iterator biter;

//in your while loop
while(i<bullets.size()+1)
{
if(bullets.getLife())
{
bullets.render(players);
}
else
{
bullets.erase(biter);
}
biter++;
i++;
}

//when u shoot a bullet !exampel"
bullets.push_back(CBullet(1,vector3df(30,10,6),vector3df(0,90,0),300,50);

I don't know if it works i just made this class up but i hope it does and helps u.
Just a tip only use it for slow and visible objects like rockets. for actual bullets u should use a raycast.