学步园

/*--------------------------------------------------------------<br /> * A calculator engine computes a closed, planar curve.<br /> * The output from the engine is connected to the translation<br /> * applied to a flower object, which consequently moves<br /> * along the path of the curve.<br /> *------------------------------------------------------------*/<br /> #include <Inventor/SoDB.h><br /> #include <Inventor/Win/SoWin.h><br /> #include <Inventor/Win/SoWinRenderArea.h><br /> #include <Inventor/engines/SoCalculator.h><br /> #include <Inventor/engines/SoElapsedTime.h><br /> #include <Inventor/engines/SoTimeCounter.h><br /> #include <Inventor/nodes/SoDirectionalLight.h><br /> #include <Inventor/nodes/SoMaterial.h><br /> #include <Inventor/nodes/SoPerspectiveCamera.h><br /> #include <Inventor/nodes/SoRotationXYZ.h><br /> #include <Inventor/nodes/SoSeparator.h><br /> #include <Inventor/nodes/SoTransform.h><br /> #include <Inventor/nodes/SoTranslation.h><br /> int<br /> main(int, char **argv)<br /> {<br /> // Initialize Inventor and Win<br /> HWND myWindow = SoWin::init(argv[0]);<br /> if (myWindow == NULL) exit(1); </p> <p> SoSeparator *root = new SoSeparator;<br /> root->ref();</p> <p> // Add a camera and light<br /> SoPerspectiveCamera *myCamera = new SoPerspectiveCamera;<br /> myCamera->position.setValue(-0.5f, -3.0f, 19.0f);<br /> myCamera->nearDistance = 10.0f;<br /> myCamera->farDistance = 26.0f;<br /> root->addChild(myCamera);<br /> root->addChild(new SoDirectionalLight);</p> <p> // Rotate scene slightly to get better view<br /> SoRotationXYZ *globalRotXYZ = new SoRotationXYZ;<br /> globalRotXYZ->axis = SoRotationXYZ::X;<br /> globalRotXYZ->angle = (float)(M_PI/7.0f);<br /> root->addChild(globalRotXYZ);</p> <p> // Read the background path from a file and add to the group<br /> SoInput myInput;<br /> if (!myInput.openFile("../data/flowerPath.iv"))<br /> exit (1);<br /> SoSeparator *flowerPath = SoDB::readAll(&myInput);<br /> if (flowerPath == NULL)<br /> exit(1);<br /> root->addChild(flowerPath);</p> <p> /////////////////////////////////////////////////////////////<br /> // CODE FOR The Inventor Mentor STARTS HERE </p> <p> // Flower group<br /> SoSeparator *flowerGroup = new SoSeparator;<br /> root->addChild(flowerGroup);</p> <p> // Read the flower object from a file and add to the group<br /> if (!myInput.openFile("../data/flower.iv"))<br /> exit (1);<br /> SoSeparator *flower= SoDB::readAll(&myInput);<br /> if (flower == NULL) exit (1);</p> <p> // Set up the flower transformations<br /> SoTranslation *danceTranslation = new SoTranslation;<br /> SoTransform *initialTransform = new SoTransform;<br /> flowerGroup->addChild(danceTranslation);<br /> initialTransform->scaleFactor.setValue(10.0f, 10.0f, 10.0f);<br /> initialTransform->translation.setValue(0.0f, 0.0f, 5.0f);<br /> flowerGroup->addChild(initialTransform);<br /> flowerGroup->addChild(flower);</p> <p> // Set up an engine to calculate the motion path:<br /> // r = 5*cos(5*theta); x = r*cos(theta); z = r*sin(theta)<br /> // Theta is incremented using a time counter engine,<br /> // and converted to radians using an expression in<br /> // the calculator engine.<br /> SoCalculator *calcXZ = new SoCalculator;<br /> SoTimeCounter *thetaCounter = new SoTimeCounter;</p> <p> thetaCounter->max = 360;<br /> thetaCounter->step = 4;<br /> thetaCounter->frequency = 0.075f;</p> <p> calcXZ->a.connectFrom(&thetaCounter->output);<br /> calcXZ->expression.set1Value(0, "ta=a*M_PI/180"); // theta<br /> calcXZ->expression.set1Value(1, "tb=5*cos(5*ta)"); // r<br /> calcXZ->expression.set1Value(2, "td=tb*cos(ta)"); // x<br /> calcXZ->expression.set1Value(3, "te=tb*sin(ta)"); // z<br /> calcXZ->expression.set1Value(4, "oA=vec3f(td,0,te)");<br /> danceTranslation->translation.connectFrom(&calcXZ->oA);</p> <p> // CODE FOR The Inventor Mentor ENDS HERE<br /> /////////////////////////////////////////////////////////////</p> <p> SoWinRenderArea *myRenderArea = new SoWinRenderArea(myWindow);<br /> myRenderArea->setSceneGraph(root);<br /> myRenderArea->setTitle("Flower Dance");<br /> myRenderArea->show();</p> <p> SoWin::show(myWindow);<br /> SoWin::mainLoop();<br /> return 0;<br /> }<br />