Irrlicht Engine

Posted: **Mon Apr 17, 2006 5:18 pm**

Hi,
I am making an FPS game using IrrWizard. I want projectiles to be displayed when a gun is fired.
I have tried looking at the Irrlicht Demo Example since it has a "visible shot" and have tried to incorporate it into the coding which is generated by IrrWizard, but with no success.

I would very grateful if someone can help me on this issue.

thx

Posted: **Mon Apr 17, 2006 5:38 pm**

What specific problems are you having? Any error messages, got any short bits of code that you can show where you've made the changes?

Posted: **Mon Apr 17, 2006 6:08 pm**

I've tried to incorporate the shoot() function(in the CDemo.cpp) from the Irrlicht Demo into GamePlayState.cpp (This is a file generated by IrrWizard).
The thing runs fine but as soon as i fire the game crashes.!

void CGamePlayState::shoot()
{
IrrlichtDevice *device;

scene::ISceneManager* sm = device->getSceneManager();
scene::ICameraSceneNode* camera = sm->getActiveCamera();

if (!camera || !m_Selector)
return;

SParticleImpact imp;
imp.when = 0;

// get line of camera

core::vector3df start = camera->getPosition();
core::vector3df end = (camera->getTarget() - start);
end.normalize();
start += end*5.0f;
end = start + (end * camera->getFarValue());

core::triangle3df triangle;

core::line3d<f32> line(start, end);

// get intersection point with map

if (sm->getSceneCollisionManager()->getCollisionPoint(
line, m_Selector, end, triangle))
{
// collides with wall
core::vector3df out = triangle.getNormal();
out.setLength(0.03f);

imp.when = 1;
imp.outVector = out;
imp.pos = end;
}
else
{
// doesnt collide with wall
end = (camera->getTarget() - start);
end.normalize();
end = start + (end * 1000);
}

// create fire ball
scene::ISceneNode* node = 0;
node = sm->addBillboardSceneNode(0,
core::dimension2d<f32>(25,25), start);

node->setMaterialFlag(video::EMF_LIGHTING, false);
node->setMaterialTexture(0, device->getVideoDriver()->getTexture("media/particle.bmp"));
node->setMaterialType(video::EMT_TRANSPARENT_ADD_COLOR);

f32 length = (f32)(end - start).getLength();
const f32 speed = 0.6f;
u32 time = (u32)(length / speed);

scene::ISceneNodeAnimator* anim = 0;

// set flight line

anim = sm->createFlyStraightAnimator(start, end, time);
node->addAnimator(anim);
anim->drop();

anim = sm->createDeleteAnimator(time);
node->addAnimator(anim);
anim->drop();

if (imp.when)
{
// create impact note
imp.when = device->getTimer()->getTime() + (time - 100);
Impacts.push_back(imp);
}
}

///////////////////////////////////

void CGamePlayState::MouseEvent(CGameManager* pManager)
{

scene::ITriangleSelector* mapSelector;

// left mouse pressed, FIRE!!!
if (pManager->getMouse() == EMIE_LMOUSE_PRESSED_DOWN )
{
if (pManager->getPlayer()->getAmmo() > 0)
{
shoot(); // this is what i have added!
pManager->getPlayer()->setAmmo(pManager->getPlayer()->getAmmo() - 4);
// get the scene node
scene::ISceneNode* node = pManager->getSceneManager()->getSceneCollisionManager()->
getSceneNodeFromCameraBB(pManager->getSceneManager()->getActiveCamera(), ID_ENEMY);

if (node->getID() == ID_ENEMY )
{
// hit an enemy, not a wall
CGameEnemy* enemy = pManager->getEnemyManager()->GetEntityFor(ENTITY_MERC);
enemy->setHealth(enemy->getHealth() - 20);
pManager->createParticleEffect(pManager, getTargetsPosition(pManager), "media/blood.bmp");
} else
pManager->createParticleEffect(pManager, getTargetsPosition(pManager), "media/smoke.bmp");
}
}
// right mouse pressed, RELOAD!!!
if (pManager->getMouse() == EMIE_RMOUSE_PRESSED_DOWN )
{
pManager->getPlayer()->setAmmo(100);
/* if (pManager->getPlayer()->getAmmo() <= 0)
pManager->getPlayer()->setAmmo(100); // 100% full */

}

}

Posted: **Mon Apr 17, 2006 7:08 pm**

What's the error you get?

Posted: **Mon Apr 17, 2006 9:25 pm**

Most of the code in the shoot() function will be redundant as all you are really trying to do is create a FlyStraightAnimator with the correct parameters.

All the parameters you need will be in the calling function, CGamePlayState::MouseEvent().

In your shoot fuction you just need to do the //create fireball and //set flight line bit to start with.

You might want to pass in a pointer to the GameManager, pManager. You can then get a pointer to Irrlicht subsytems like the SceneManager (sm) in the code you have like this :

Code: Select all

    pManager->getSceneManager();

to create a FlyStraightAnimator you can do this:

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  pManager->getSceneManager()->createFlystraightAnimator(camPos,targetPos, 5000);

to get the first parameter, camPos:

Code: Select all

   pManager->getSceneManager()->getActiveCamera()->getPosition()

and the second, the target position, wall or enemy (getTargetsPosition() is a member function of CGamePlayState() by the looks)

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  getTargetsPosition(pManager)

and so on.

Sorry it's only high level help, but I think in this case it's better to step back from the code and think what you want to achieve from it. Then start from a blank and build it up rather than cut and paste a large amount of code and then whittle it back.
________
Avatar: the last airbender forum

Posted: **Tue Apr 18, 2006 12:41 pm**

Thank you area51, I finally got it to work!

But i've got one problem - How do I actually create the fireball? because at the moment i've only got a white cube being fired!

when i put in this piece of code the game crashes when i fire the gun.

Code: Select all

node2->setMaterialTexture(0, m_pDevice->getVideoDriver()->getTexture("media/particle.bmp"));

Ive got rid of the shoot() function and just put the coding in CGamePlayState::MouseEvent().

Here is the CGamePlayState::MouseEvent() so far:

Code: Select all

void CGamePlayState::MouseEvent(CGameManager* pManager)
{
    
		scene::ITriangleSelector* mapSelector;

     // left mouse pressed, FIRE!!!
	if (pManager->getMouse() == EMIE_LMOUSE_PRESSED_DOWN ) 
    {
        if (pManager->getPlayer()->getAmmo() > 0)
        {                   

           pManager->getSceneManager(); 
           core::vector3df camPos =      pManager->getSceneManager()->getActiveCamera()->getPosition(); 
           core::vector3df targetPos = getTargetsPosition(pManager);
            scene::ICameraSceneNode* camera = pManager->getSceneManager()->getActiveCamera();	
            	
           pManager->getSceneManager()->createFlyStraightAnimator(camPos,targetPos, 5000); 
          	   
              
              ///////////////////
           pManager->getPlayer()->setAmmo(pManager->getPlayer()->getAmmo() - 4);
           // get the scene node
           scene::ISceneNode* node = pManager->getSceneManager()->getSceneCollisionManager()->
                 getSceneNodeFromCameraBB(pManager->getSceneManager()->getActiveCamera(), ID_ENEMY);
   
   
   core::triangle3df triangle;
   core::line3d<f32> line(camPos, targetPos);
   	SParticleImpact imp; 
	imp.when = 0;

	// get intersection point with map

	if (pManager->getSceneManager()->getSceneCollisionManager()->getCollisionPoint(
		line, m_Selector, targetPos, triangle))
	{
		// collides with wall
		core::vector3df out = triangle.getNormal();
		out.setLength(0.03f);

		imp.when = 1;
		imp.outVector = out;
		imp.pos = targetPos;
	}
	else
	{
		// doesnt collide with wall
		targetPos = (camera->getTarget() - camPos);
		targetPos.normalize();
		targetPos = camPos + (targetPos * 1000);
	}
   
   scene::ISceneNode* node2 = 0;
	node2 = pManager->getSceneManager()->addBillboardSceneNode(0,
		core::dimension2d<f32>(25,25), camPos);

	node2->setMaterialFlag(video::EMF_LIGHTING, false);

**********************************************************
//This next line is giving me problems. If i put it in then the game crashes on firing, otherwise i get a white cube being fired!
**********************************************************

	This one -> //node2->setMaterialTexture(0, m_pDevice->getVideoDriver()->getTexture("media/particle.bmp"));


	node2->setMaterialType(video::EMT_TRANSPARENT_ADD_COLOR);

   
   	scene::ISceneNodeAnimator* anim = 0;
   	anim = pManager->getSceneManager()->createFlyStraightAnimator(camPos, targetPos, 500);
	node2->addAnimator(anim);	
	anim->drop();

	anim = pManager->getSceneManager()->createDeleteAnimator(500);
	node2->addAnimator(anim);
	anim->drop();

Posted: **Tue Apr 18, 2006 8:05 pm**

I can't see where you've initialised m_pDevice, so use this instead:

Code: Select all

node2->setMaterialTexture(0, pManager->getDevice()->getVideoDriver()->getTexture("media/particle.bmp"));

Also this code below:

Code: Select all

core::triangle3df triangle; 
   core::line3d<f32> line(camPos, targetPos); 
      SParticleImpact imp; 
   imp.when = 0; 

   // get intersection point with map 

   if (pManager->getSceneManager()->getSceneCollisionManager()->getCollisionPoint( 
      line, m_Selector, targetPos, triangle)) 
   { 
      // collides with wall 
      core::vector3df out = triangle.getNormal(); 
      out.setLength(0.03f); 

      imp.when = 1; 
      imp.outVector = out; 
      imp.pos = targetPos; 
   } 
   else 
   { 
      // doesnt collide with wall 
      targetPos = (camera->getTarget() - camPos); 
      targetPos.normalize(); 
      targetPos = camPos + (targetPos * 1000); 
   }

isn't doing that much more than this:

Code: Select all

    core::vector3df targetPos = getTargetsPosition(pManager);

________
Yamaha fj600

Posted: **Wed Apr 19, 2006 12:52 pm**

Thanks area51, youre a star!

it works like a charm!

Irrlicht Engine

shooting!

shooting!

shooting