getscenenodeandcollisionpointfromray() return nothing

[Jackie1234]

Hi,

I have a problem with getscenenodeandcollisionpointfromray(), this fonctio always return a null sceneNode.
I have checked that the ray what i use cross some other nodes with draw3Dline, but the fonction getscenenodeandcollisionpointfromray() don't return a node.
I want to check all the scene.

My code (take in example 7, collision)

Code: Select all

irr::scene::ISceneCollisionManager* collMan = m_scnMgr->getSceneCollisionManager();
 
irr::core::line3d<f32> ray;
irr::core::vector3df p = m_perso->getNode()->getPosition();
p.X -= 20;
                ray.start = m_perso->getNode()->getPosition();
                ray.end = p;
 
                irr::core::vector3df intersection;
                irr::core::triangle3df hitTriangle;
 
                irr::scene::ISceneNode * selectedSceneNode =
                        collMan->getSceneNodeAndCollisionPointFromRay(
                                        ray,
                                        intersection, 
                                        hitTriangle, 
                                        m_scnMgr->getRootSceneNode()->getID(), // or just 0
                                        0); 
 
if (selectedSceneNode || collMan->getSceneNodeAndCollisionPointFromRay(
                                        ray,
                                        intersection, 
                                        hitTriangle, 
                                        m_scnMgr->getRootSceneNode()->getID(), // or just 0
                                        0))
cout << "The code works !" << endl;
 
else
cout << ":-(" << endl;
 
 

My code is correct ?
Have you got an idea of the origin of the problem ?

Thank you and sorry for my poor english.

[CuteAlien]

When using m_scnMgr->getRootSceneNode()->getID() it might not work but seeing that you wrote "or just 0" you have probably tested with 0 as well. Otherwise from what I see in the code you posted above it looks correct. So not sure where your problem is.

[Jackie1234]

Yes i have try 0.

[smso]

My guess is something wrong with:

Code: Select all

ray.end = p;

try:

Code: Select all

p.X -= 2000.0f; // or higher
...
ray.end = p;

[blAaarg]

Yes, as CuteAlien pointed out, you have your last two parameters swapped when you call "getSceneNodeAndCollisionPointFromRay()". Also, each node that you test against has to have a triangle selector set for it or that method ("getSceneNodeAndCollisionPointFromRay()") won't work for that node.

Use the scene manager to createTriangleSelector() for the node and then call setTriangleSelector(). According to the documentation:

Some nodes may create their own selector by default, so it would be good to check if there is already a selector in this node by calling ISceneNode::getTriangleSelector().

In which case, I don't know, you have some other problem.


Also, as smso pointed out, your test numbers seem obscure and might not actually be making a collision, but that's hard to tell with what you have shown, so maybe that part is okay.

[Jackie1234]

Also, each node that you test against has to have a triangle selector set for it or that method ("getSceneNodeAndCollisionPointFromRay()") won't work for that node.

Is it possible that my code don't work because I have ->drop(); my selectors and metaselectors ?

[smso]

Have you set up the triangle selector?

Regards from
smso

[Jackie1234]

Yes.
But I shouldn't drop them ?

[smso]

Yes.
But I shouldn't drop them ?

Just try!

Regards
smso

[serengeor]

Yes.
But I shouldn't drop them ?

You should drop them after you attach them to nodes, as you need to decrease the reference counter.

[Jackie1234]

Use the scene manager to createTriangleSelector() for the node and then call setTriangleSelector(). According to the documentation:

I'm a noob, I hadn't use setTriangleSelector !
It works very well, happy !
Thank you