what i'm doing bad in this collision detection?

[saulotmalo]

i think i did it well but... here is some code if anyone can help me out how to solve it... well...

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    //first insert a square wich will be the wall (1.0 ver )
    node = smgr->addTestSceneNode();
    node->setScale(core::vector3df(1,20,1));
    node->setPosition(core::vector3df(130,-105,0));    
    select=node->getTriangleSelector(); //here i get the triangle selector to do the comparision ( or i think it works that way... )

....

   //this square will be moving arround the screen...
     scene::ISceneNode* node = 0;
    node = smgr->addTestSceneNode();
    node->setPosition(core::vector3df(30,-60,0));   

    core::vector3d<f32> start,end;

	while(device->run())
	{
        start=node->getPosition();
       node->setPosition(node->getPosition()+core::vector3df(0.1,-0.1,0));
       end=node->getPosition();

        core::vector3df colision;  
        core::triangle3df triangulo;
        core::line3d<f32> line(start,end);

     smgr->getSceneCollisionManager()->getCollisionPoint(line,select, colision,triangulo);


		driver->beginScene(true, true, SColor(255,100,101,140));

		smgr->drawAll();
		guienv->drawAll();

		driver->endScene();
	}

with this code i get the vector 0,0 so i think i have something don't working but i don't see it.. i've been using the API doc alot also i try to findo out what can be the problem. also the line is working, i think so because when i try to do the average point it is on the center.

By the way... the line height it is infinite? i mean.. it starts and ends when it does the test or have an start and end? ... i realy speak bad english :'(

[funcdoobiest]

The line Height is not infinite, if the height your line is at is lower than the bottom of the wall it will miss. I guess you mean the vector line is (0,0,0), which means you are getting no collision.

getCollisionPoint returns true if you collide so first do this

Code: Select all

if(smgr->getSceneCollisionManager()->getCollisionPoint(line,select, colision,triangulo))
{
    //collision response etc.
    //if you do not reach this you have definitely not collided
}

beyond that you haven't really told us in what way it doesn't work. A guess would be that your test line is too small, it needs to be long enough to stick out of the box or the box will go half way through the wall before its notices, try putting end further away

[saulotmalo]

thanks for the help your way of get how if there is a collision is pretty good

also i've been working and i've found the mistake it was that

select=node->getTriangleSelector();

doesn't lend you a triangle selector , it only return one if its atached to the node. also i've used a function that creates a triangle selector from a bounding box and it works...

now i'm getting a problem wich doens't know how to solve is this...

if i have a node box and it is hit by the ball.. then how can i tell the ball to be reflected? ... hard for me at least... but thanks to all people my game is looking better