Problem with triangle selector

[Virror]

I have a problem with a triangle selector. I have a cube that consists of 20x20x20 vertices based on a volume of voxels.
I create a triangleSelector so when i click the cube, i transform the coordinates from a ray collision and remove the correct voxel, then i recalculate the mesh for that area and redo the selector.
Problem is that i don't get a "hit" on the whole cube, just some of the sides, what can cause this problem?

[REDDemon]

Do you use the built-in selector or do you have wrote your own selector?

[CuteAlien]

Fixing collision problems is very hard to do without a testcase (and often even hard with a testcase....).

[randomMesh]

Please show a minimal compilable example.

[Virror]

A compilable example would be hard cause its integrated into the game I'm making and using external libs and stuff. But i will try to post as much relevant code as i can.
Problem is that on half of the cube I'm not getting a ray hit at all, or working camera collision.

Create class and then cube:

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ITerrainVoxelSceneNode * test = new ITerrainVoxelSceneNode(0, irrScene, MT_WORLD, vector3df(2500*2, 450*2, 2000*2),
    vector3df(0, 0, 0),vector3df(30.0F, 30.0F, 30.0F));
ISceneNode * test2 = test->loadCube(20, SColor(255, 255, 255, 255));

Create node and selector:

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newMesh = new SMesh;
ITriangleSelector* meshSelector = 0;
IMeshBuffer * newBuffer = ConvertMesh(*mesh, vertexColor);
newMesh->addMeshBuffer(newBuffer);
newMesh->recalculateBoundingBox();
SceneManager->getMeshManipulator()->makePlanarTextureMapping(newMesh, 2.0f);
newNode = SceneManager->addMeshSceneNode(newMesh, Parent, ID, RelativeTranslation, RelativeRotation, RelativeScale);
meshSelector = SceneManager->createTriangleSelector(newMesh, newNode);
newNode->setTriangleSelector(meshSelector);
meshSelector->drop();
 

Cast ray and calculate voxel position if hit:

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vector3df intersection;
triangle3df hitTriangle;
line3d<f32> ray;
ray.start = camera->getPosition();
ray.end = ray.start + (camera->getTarget() - ray.start).normalize() * 300.0f;
ISceneNode * selectedSceneNode = collMan->getSceneNodeAndCollisionPointFromRay(ray, intersection, hitTriangle, 0, 0); 
    if(selectedSceneNode)
    {
        switch(selectedSceneNode->getID())
        {
            case MT_WORLD:
            {
                int posX, posY, posZ;
                posX = (int)(intersection.X - selectedSceneNode->getAbsolutePosition().X);
                posY = (int)(intersection.Y - selectedSceneNode->getAbsolutePosition().Y);
                posZ = (int)(intersection.Z - selectedSceneNode->getAbsolutePosition().Z);
                voxelScene->removeVoxel(posX, posY, posZ);
                break;
            }
        }
    }
 

[CuteAlien]

Hm, really hard without a working test-example :-(
First idea - you are only using 300 units length for your collision-ray, maybe it's beyond that? Try working with the camera far-value instead to be sure you can hit anything that's visible for the user.

[Virror]

I know its hard without an example to debug : /
The 300 length should be ok if I'm standing right next to the cube right? Its working from one side, so it should work from the other side to if im close.
The reason for the 300 is that i don't want the player to be able to dig to far away, that would feel very unrealistic, but i can try to change it just to test : )

Edit: Setting range wont help : /

[CuteAlien]

Did you debug if you maybe hit something else? (like your own player ... )

[Virror]

No collision at all, just jumps past "if(selectedSceneNode)"

[aanderse]

somewhat unrelated, just for my own understanding of irrlicht collision system, and could be stupid question but... if you actually just have a cube why don't you just use the bounding box triangle selector via ISceneManager::createTriangleSelectorFromBoundingBox?

[Virror]

Well, the thing is that i can "cut" in the stone shaping it, so i need mesh collision to transform the collision point into numbers i use for mesh transformation.

[aanderse]

ah didn't realize you could reshape the cube
so you have to drop the triangle selector and create a new one every time you reshape the mesh then?

[Virror]

Thats what im doing currently, it was my guess it was the only way. But creating a selector is pretty quick.
This will be a terrain later, just a cube now for easy testing.

[aanderse]

thanks for the information
sorry for hijacking your thread!

[zprg]

virror wrote:
>and using external libs and stuff. But i will try to post as much relevant code as i can.
>Problem is that on half of the cube I'm not getting a ray hit at all, or working camera collision.

ah i think you also use polyvox and i run into the same problem atm. from the half of the polyvoxmesh i get no collision.
so cause you had the same problem is seems that the reason of the problem is not irrlicht, please how solved the problem?