irredit and creating collisions

Dutch · Post by **Dutch** » Mon Sep 04, 2006 2:16 am

Hi folks

I'm loading irredit files but have a problem setting up collisions. This is how far i got:

smgr->loadScene("scenes/example.irr", 0);
	scene::ISceneNode* level = smgr->getSceneNodeFromId(5);
	smgr->createOctTreeTriangleSelector(??????, level ,128);

	scene::ITriangleSelector* selector = 0;
	

    scene::ICameraSceneNode* camera = 
		smgr->addCameraSceneNodeFPS(0, 100.0f, 300.0f, -1, 0, 0, true);
	camera->setPosition(core::vector3df(0,200,0));

	scene::ISceneNodeAnimator* anim = smgr->createCollisionResponseAnimator(
		selector, camera, core::vector3df(30,50,30),
		core::vector3df(0,-3,0), 
		core::vector3df(0,50,0));
	camera->addAnimator(anim);
	anim->drop();

How do i get a pointer to the mesh in the irredit file needed for the createOctTreeTriangleSelector

many thanks

dutch

Amt0571 · Post by **Amt0571** » Wed Sep 06, 2006 6:08 pm

UP! I'm also very interested on this!

mandrav · Post by **mandrav** » Wed Sep 06, 2006 7:59 pm

I don't know of any way to do this because you can only search for ISceneNode (which doesn't contain an IMesh).
If I 'm right about this then it is a huge limitation. The actual mesh is needed for just about everything, after you load your scene: collision detection, physics, etc.

vitek · Post by **vitek** » Wed Sep 06, 2006 8:10 pm

The scene node has a getType() method. If the type is ESNT_MESH you could cast the ISceneNode to an IMeshSceneNode. Now only if IMeshSceneNode had a getMesh() accessor...

mandrav · Post by **mandrav** » Wed Sep 06, 2006 9:12 pm

vitek wrote:Now only if IMeshSceneNode had a getMesh() accessor...

Yes, that is outright strange. I don't see the reason why there isn't such a method (const even).

sudi · Post by **sudi** » Wed Sep 06, 2006 9:50 pm

It's because an ISceneNode could be everything....a light a camera or something the user defined and as far as i know a light or a camera doesn't have a mesh and u don'T know what the user could use the scenenode for so it's good that there isn't such a method.

but i worked around that with the following trick:

Code: Select all

struct NodeCreationParams
{
      std::string name;
      std::string mesh;
      std::string type;
      vector3df position;
      vector3df rotation;
      vector3df scale;
};
NodeCreationParams* tnode;
NodeCreationParams* tempnode;

Code: Select all

IXMLReader* reader = device->getFileSystem()->createXMLReader(sceneName.c_str());

    if (reader == 0)
     return false; // file could not be opened

     // parse the file until end reached
    while(reader->read())
    {
                        // based on xml->getNodeType(), do something.
                        switch(reader->getNodeType())
                        {
                            case EXN_ELEMENT:
                                if(stringw("node") == reader->getNodeName())
                                {
                                    ///cout<<"Found NewNode"<<endl;
                                    if(tnode == NULL)
                                    {
                                        tnode = new NodeCreationParam;
                                        tnode->parent = NULL;
                                    }
                                    else
                                    {
                                        tempnode = new NodeCreationParam;
                                        tempnode->parent = tnode;
                                        tnode = tempnode;
                                        tempnode = NULL;
                                    }
                                    tnode->type = (char*)stringc(reader->getAttributeValue(L"type")).c_str();
                                    cout<<"Handeld Node"<<endl;
                                }
                                if(tnode != NULL)
                                {
                                    ///cout<<"Found NodeParameter: "<<stringc(reader->getNodeName()).c_str()<<" / "<<stringc(reader->getAttributeValue(L"name")).c_str()<<endl;
                                    if(stringw("string") == reader->getNodeName())
                                    {
                                        if(stringw("Name") == reader->getAttributeValue(L"name"))
                                        {
                                            tnode->name = (char*)stringc(reader->getAttributeValue(L"value")).c_str();
                                            cout<<"Name: "<<tnode->name;
                                        }
                                    }
                                    if(stringw("string") == reader->getNodeName())
                                    {
                                        if(stringw("Mesh") == reader->getAttributeValue(L"name"))
                                        {
                                            tnode->mesh = (char*)stringc(reader->getAttributeValue(L"value")).c_str();
                                            cout<<"Mesh: "<<tnode->mesh;
                                        }
                                    }
                                    if(stringw("vector3d") == reader->getNodeName())
                                    {
                                        if(stringw("Position") == reader->getAttributeValue(L"name"))
                                        {

                                            sscanf((char*)stringc(reader->getAttributeValue(L"value")).c_str(),"%f,%f,%f", &tnode->position.X, &tnode->position.Y, &tnode->position.Z);

                                        }
                                        if(stringw("Rotation") == reader->getAttributeValue(L"name"))
                                        {

                                            sscanf((char*)stringc(reader->getAttributeValue(L"value")).c_str(),"%f,%f,%f", &tnode->rotation.X, &tnode->rotation.Y, &tnode->rotation.Z);

                                        }
                                        if(stringw("Scale") == reader->getAttributeValue(L"name"))
                                        {

                                            sscanf((char*)stringc(reader->getAttributeValue(L"value")).c_str(),"%f,%f,%f", &tnode->scale.X, &tnode->scale.Y, &tnode->scale.Z);

                                        }
                                    }
                                    ///cout<<"Handeld NodeParameter"<<endl;
                                }
                                break;

                            case EXN_ELEMENT_END:
                                if(stringw("node") == reader->getNodeName())
                                {
                                    if(tnode != NULL)
                                    {
                                        if(!tnode->name.empty())
                                        {
                                            cout<<"Nodename: "<<tnode->name<<endl;
                                            if(tnode->type == "mesh")
                                            {
                                                //This function will build the collision
                                                buildCollisionMesh(*tnode);
                                            }
                                        }

                                        if(tnode->parent == NULL)
                                        {
                                            delete tnode;
                                            tnode = NULL;
                                        }
                                        else if(tnode->parent != NULL)
                                        {
                                            tempnode = tnode;
                                            tnode = tnode->parent;
                                            delete tempnode;
                                            tempnode = NULL;
                                        }
                                    }
                                }
                                break;
                        }
    }

    // delete the xml parser after usage
    delete reader;

vitek · Post by **vitek** » Wed Sep 06, 2006 10:27 pm

It's because an ISceneNode could be everything....a light a camera or something the user defined and as far as i know a light or a camera doesn't have a mesh

You didn't read very well. The issue is why does the IMeshSceneNode interface not provide a getMesh() accessor? All IMeshSceneNode derived classes _should_ have a mesh. You can call setMesh(), why can't you call getMesh()?

Travis

mandrav · Post by **mandrav** » Thu Sep 07, 2006 6:51 am

t's because an ISceneNode could be everything....a light a camera or something the user defined and as far as i know a light or a camera doesn't have a mesh and u don'T know what the user could use the scenenode for so it's good that there isn't such a method.

We were talking about IMeshSceneNode...