Open Inventor练习-SoRayPickAction和SoMouseButtonEvent点选操作

SoRayPickAction是三维物体射线选择操作，SoPickedPoin用来存放选择的坐标，SoMouseButtonEvent用来鼠标操作信息处理。例子中获得鼠标点击物体的类型和坐标位置信息，在Console控制台窗口中输出。代码如下。

#define COIN_DLL  #define SOWIN_DLL  // 加载COIN库文件  #ifdef _DEBUG  #pragma comment(lib, "SoWin1d.lib")  #pragma comment(lib, "Coin3d.lib")  #else  #pragma comment(lib, "SoWin1.lib")  #pragma comment(lib, "Coin3.lib")  #endif  // 添加COIN头文件-Window操作显示库和节点库  #include <Inventor/Win/viewers/SoWinExaminerViewer.h>#include <Inventor/Win/SoWin.h>#include <Inventor/nodes/SoSeparator.h>#include <Inventor/nodes/SoSphere.h>#include <Inventor/nodes/SoMaterial.h>#include <Inventor/nodes/SoEventCallback.h>#include <Inventor/actions/SoRayPickAction.h>#include <Inventor/events/SoMouseButtonEvent.h>#include <Inventor/SoPickedPoint.h>SoWinExaminerViewer *viewer = NULL;SoSeparator *root = NULL;void button_event_cb(void *userdata, SoEventCallback *node){const SoMouseButtonEvent *event = (SoMouseButtonEvent *)node->getEvent();SbVec2s pos = event->getPosition(viewer->getViewportRegion());if (event->getButton()==SoMouseButtonEvent::BUTTON1 &&event->getState()==SoButtonEvent::DOWN) {SoRayPickAction pick(viewer->getViewportRegion());pick.setPoint(pos);pick.apply(viewer->getSceneManager()->getSceneGraph());SoPickedPoint *pp = pick.getPickedPoint();if (pp) {const SoPath *path = pp->getPath();SbVec3f p = pp->getPoint();SoNode *node = path->getTail();printf("Picked shape: %s (%s), point: (%f %f %f)\n", node->getName().getString(), node->getTypeId().getName().getString(),p[0], p[1], p[2]);}}}int main (int argc, char ** argv){if (argc != 2) {fprintf(stderr, "Usage: %s <file.iv>\n", argv[0]);exit(1);}// Initialize Coin & SoWinHWND win = SoWin::init(argv[0]);if (win == NULL) exit(1);// Read scene graph from fileSoInput in;if (!in.openFile(argv[1])) {fprintf(stderr, "Unable to open file \"%s\"\n",argv[1]);exit(1);}SoSeparator *fileroot = SoDB::readAll(&in);in.closeFile();root = new SoSeparator;root->ref();SoEventCallback *cb = new SoEventCallback;cb->addEventCallback(SoMouseButtonEvent::getClassTypeId(), button_event_cb, NULL);root->addChild(cb);root->addChild(fileroot);// Create the viewerviewer = new SoWinExaminerViewer(win);viewer->setSceneGraph(root);viewer->setTitle("picking example");viewer->setViewing(FALSE);viewer->setDecoration(FALSE);// Show the windowviewer->show();SoWin::show(win);// Enter the application event loopSoWin::mainLoop();// Free scene graph memoryroot->unref();return 0;}

iv文件如下：

#Inventor V2.1 ascii# open this file using the "raypick" demo programSeparator {  DEF A Separator {    DEF D Translation {      translation -5 -5 0    }    DEF E Material {      diffuseColor 0 1 1    }    DEF E2 MaterialBinding {      value PER_PART    }    DEF F Cube {    }  }  DEF B SoSphere {  }  DEF C Separator {    DEF G Translation {      translation 5 0 0    }    DEF H Cylinder {    }  }}

运行效果如下