海军osg教程源代码之金子塔的绘制

#include <osg/Node> #include <osg/Group> #include <osg/Geode> #include <osg/Geometry> #include <osg/Texture2D> #include <osg/StateSet> #include <osg/PositionAttitudeTransform> #include <osgViewer/Viewer> #include <osgDB/ReadFile> #include <osg/Ref_ptr> int main() { osg::Group* root = new osg::Group(); osg::Geode* pyramidGeode = new osg::Geode(); osg::Geometry* pyramidGeometry = new osg::Geometry(); pyramidGeode->addDrawable(pyramidGeometry); root->addChild(pyramidGeode); osg::Vec3Array* pyramidVertices = new osg::Vec3Array; pyramidVertices->push_back( osg::Vec3( 0, 0, 0) ); // 左前 pyramidVertices->push_back( osg::Vec3(10, 0, 0) ); // 右前 pyramidVertices->push_back( osg::Vec3(10,10, 0) ); // 右后 pyramidVertices->push_back( osg::Vec3( 0,10, 0) ); // 左后 pyramidVertices->push_back( osg::Vec3( 5, 5,10) ); // 塔尖 pyramidGeometry->setVertexArray( pyramidVertices ); osg::DrawElementsUInt* pyramidBase = new osg::DrawElementsUInt(osg::PrimitiveSet::QUADS, 0); pyramidBase->push_back(3); pyramidBase->push_back(2); pyramidBase->push_back(1); pyramidBase->push_back(0); pyramidGeometry->addPrimitiveSet(pyramidBase); //重复这一过程，添加金字塔的每个面。再次注意，顶点是以逆时针为顺序添加的。 osg::DrawElementsUInt* pyramidFaceOne = new osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLES, 0); pyramidFaceOne->push_back(0); pyramidFaceOne->push_back(1); pyramidFaceOne->push_back(4); pyramidGeometry->addPrimitiveSet(pyramidFaceOne); osg::DrawElementsUInt* pyramidFaceTwo = new osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLES, 0); pyramidFaceTwo->push_back(1); pyramidFaceTwo->push_back(2); pyramidFaceTwo->push_back(4); pyramidGeometry->addPrimitiveSet(pyramidFaceTwo); osg::DrawElementsUInt* pyramidFaceThree = new osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLES, 0); pyramidFaceThree->push_back(2); pyramidFaceThree->push_back(3); pyramidFaceThree->push_back(4); pyramidGeometry->addPrimitiveSet(pyramidFaceThree); osg::DrawElementsUInt* pyramidFaceFour = new osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLES, 0); pyramidFaceFour->push_back(3); pyramidFaceFour->push_back(0); pyramidFaceFour->push_back(4); pyramidGeometry->addPrimitiveSet(pyramidFaceFour); //定义一个Vec4的数组，用于保存颜色值。 osg::Vec4Array* colors = new osg::Vec4Array; colors->push_back(osg::Vec4(1.0f, 0.0f, 0.0f, 1.0f) ); //索引0 红色 colors->push_back(osg::Vec4(0.0f, 1.0f, 0.0f, 1.0f) ); //索引1 绿色 colors->push_back(osg::Vec4(0.0f, 0.0f, 1.0f, 1.0f) ); //索引2 蓝色 colors->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f) ); //索引3 白色 osg::TemplateIndexArray <unsigned int, osg::Array::UIntArrayType,4,4> *colorIndexArray; colorIndexArray = new osg::TemplateIndexArray<unsigned int, osg::Array::UIntArrayType,4,4>; colorIndexArray->push_back(0); // vertex 0 assigned color array element 0 colorIndexArray->push_back(1); // vertex 1 assigned color array element 1 colorIndexArray->push_back(2); // vertex 2 assigned color array element 2 colorIndexArray->push_back(3); // vertex 3 assigned color array element 3 colorIndexArray->push_back(0); // vertex 4 assigned color array element 0 pyramidGeometry->setColorArray(colors); pyramidGeometry->setColorIndices(colorIndexArray); pyramidGeometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX); osg::Vec2Array* texcoords = new osg::Vec2Array(5); (*texcoords)[0].set(0.00f,0.0f); (*texcoords)[1].set(0.25f,0.0f); (*texcoords)[2].set(0.50f,0.0f); (*texcoords)[3].set(0.75f,0.0f); (*texcoords)[4].set(0.50f,1.0f); pyramidGeometry->setTexCoordArray(0,texcoords); //初始化位置变换节点 osg::PositionAttitudeTransform* pyramidTwoXForm =new osg::PositionAttitudeTransform(); //使用osg::Group的addChild方法，将位置变换节点添加到根节点的子节点上，并将金字塔节点作为变换节点的子节点 root->addChild(pyramidTwoXForm); pyramidTwoXForm->addChild(pyramidGeode); // 初始化一个Vec3实例，用于改变模型在场景中的位置 osg::Vec3 pyramidTwoPosition(15,0,0); pyramidTwoXForm->setPosition( pyramidTwoPosition ); //最后，设置视窗类并进入仿真循环。 osgViewer::Viewer viewer; viewer.setSceneData( root ); return viewer.run(); }