Ogre中的碰撞检测(4)

通过设置不同的掩码，可以实现有选择的碰撞检测，下面的代码中，ogre头能被查询器检测到，而机器人由于掩码不同，不能被检测到。

 

 

Code
#include "ExampleApplication.h"

RaySceneQuery* raySceneQuery = 0;

// Event handler to add ability to alter curvature
class TerrainFrameListener : public ExampleFrameListener
{
public:
    SceneManager* mSceneMgr;
    TerrainFrameListener(SceneManager *sceneMgr,RenderWindow* win, Camera* cam)
        : ExampleFrameListener(win, cam)
    {
        // Reduce move speed
        mMoveSpeed = 50;
        mSceneMgr = sceneMgr;
    }

    bool frameRenderingQueued(const FrameEvent& evt)
    {
        if( ExampleFrameListener::frameRenderingQueued(evt) == false )
        return false;

        // clamp to terrain
        static Ray updateRay;
        updateRay.setOrigin(mCamera->getPosition());
        updateRay.setDirection(Vector3::NEGATIVE_UNIT_Y);
        raySceneQuery->setRay(updateRay);
        RaySceneQueryResult& qryResult = raySceneQuery->execute();
        RaySceneQueryResult::iterator i = qryResult.begin();
        if (i != qryResult.end() && i->worldFragment)//把摄像机定在地形10个单位高的地方。
        {
            mCamera->setPosition(mCamera->getPosition().x, 
                i->worldFragment->singleIntersection.y + 10, 
                mCamera->getPosition().z);
        }
        //创建球形查询器,第二个参数表示掩码,默认情况下为-1
        SphereSceneQuery * pQuery=mSceneMgr->createSphereQuery(Sphere(mCamera->getPosition(),10),0x01);
        SceneQueryResult QResult=pQuery->execute();
        for (std::list<MovableObject*>::iterator iter = QResult.movables.begin(); iter != QResult.movables.end();++iter)
        {
            MovableObject* pObject=static_cast<MovableObject*>(*iter);
            if(pObject)
            {
                if(pObject->getMovableType()=="Entity")
                {
                    Entity* ent = static_cast<Entity*>(pObject);
                    //if(ent->getName()=="Head")
                    //{
                    //    //m_node->setScale(10,10,10);
                    //    pObject->getParentNode()->scale(0.5,0.5,0.5);
                    //    break;
                    //}
                    Ogre::Vector3 v = mCamera->getPosition();
                    Ogre::Vector3 d = mCamera->getDirection();
                    v = v + d*(-1);
                    mCamera->setPosition(v);

                }
            }
        }

        return true;

    }

};



class TerrainApplication : public ExampleApplication
{
public:
    TerrainApplication() {}

    ~TerrainApplication()
    {
        delete raySceneQuery;
    }

protected:


    virtual void chooseSceneManager(void)
    {
        // Get the SceneManager, in this case a generic one
        mSceneMgr = mRoot->createSceneManager("TerrainSceneManager");
    }

    virtual void createCamera(void)
    {
        // Create the camera
        mCamera = mSceneMgr->createCamera("PlayerCam");

        // Position it at 500 in Z direction
        mCamera->setPosition(Vector3(128,25,128));
        // Look back along -Z
        mCamera->lookAt(Vector3(0,0,-300));
        mCamera->setNearClipDistance( 1 );
        mCamera->setFarClipDistance( 1000 );

    }
   
    // Just override the mandatory create scene method
    void createScene(void)
    {

        // Set ambient light
        mSceneMgr->setAmbientLight(ColourValue(0.5, 0.5, 0.5));

        // Create a light
        Light* l = mSceneMgr->createLight("MainLight");
        // Accept default settings: point light, white diffuse, just set position
        // NB I could attach the light to a SceneNode if I wanted it to move automatically with
        //  other objects, but I don't
        l->setPosition(20,80,50);

        // Fog
        // NB it's VERY important to set this before calling setWorldGeometry 
        // because the vertex program picked will be different
        ColourValue fadeColour(0.93, 0.86, 0.76);
        mSceneMgr->setFog( FOG_LINEAR, fadeColour, .001, 500, 1000);
        mWindow->getViewport(0)->setBackgroundColour(fadeColour);

        std::string terrain_cfg("terrain.cfg");
        mSceneMgr -> setWorldGeometry( terrain_cfg );
        // Infinite far plane?
        if (mRoot->getRenderSystem()->getCapabilities()->hasCapability(RSC_INFINITE_FAR_PLANE))
        {
            mCamera->setFarClipDistance(0);
        }

        // Set a nice viewpoint
        mCamera->setPosition(707,2500,528);
        mCamera->setOrientation(Quaternion(-0.3486, 0.0122, 0.9365, 0.0329));
        //mRoot -> showDebugOverlay( true );

        raySceneQuery = mSceneMgr->createRayQuery(
            Ray(mCamera->getPosition(), Vector3::NEGATIVE_UNIT_Y));//光线的位置和方向，垂直向下

        Entity* ogreHead = mSceneMgr->createEntity("Head", "ogrehead.mesh");
        ogreHead->setQueryFlags(0x01);//和球形场景查询器的掩码相同，所以该实体能被球形实体检测到

        //创建ogre head实体，测试通过射线查询movable来实现摄像机碰撞检测
        SceneNode* headNode = mSceneMgr->getRootSceneNode()->createChildSceneNode("ogreHead");
        headNode->attachObject(ogreHead);
        headNode->setPosition(500.0, 100.0, 500.0);
        headNode->scale(Vector3(2,2,2));

        Entity* entRobot = mSceneMgr->createEntity("Robot", "robot.mesh");
        entRobot->setQueryFlags(0x02);//掩码为2，不会和球形场景查询器检测到

        SceneNode* RobotNode = mSceneMgr->getRootSceneNode()->createChildSceneNode("nodeRobot");
        RobotNode->attachObject(entRobot);
        RobotNode->setPosition(400.0, 50.0, 400.0);
        RobotNode->scale(Vector3(2,2,2));
        

    }
    // Create new frame listener
    void createFrameListener(void)
    {
        mFrameListener= new TerrainFrameListener(mSceneMgr,mWindow, mCamera);
        mRoot->addFrameListener(mFrameListener);
    }

};