OSG绘制视锥体

本文主要是介绍OSG绘制视锥体，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

最近要来实现一个相机位姿态可视化的需求，不想使用pangolin，不好集成，想用osg来做可视化。以下是demo效果。

代码实现：

// Cone_of_vision.cpp : 定义控制台应用程序的入口点。
//#include "stdafx.h"
#include <osgViewer/Viewer>
#include <osg/Camera>
#include <osg/Geode>
#include <osg/Geometry>// 在创建相机视锥体时计算视锥体顶点和设置边线
osg::ref_ptr<osg::Geode> createCameraFrustum(osg::Camera* camera) {osg::ref_ptr<osg::Geode> geode = new osg::Geode();osg::ref_ptr<osg::Geometry> geometry = new osg::Geometry();// 获取相机的投影矩阵和视图矩阵osg::Matrixd projectionMatrix = camera->getProjectionMatrix();osg::Matrixd viewMatrix = camera->getViewMatrix();// 计算视锥体顶点坐标osg::Vec3Array* vertices = new osg::Vec3Array(9);double nearPlane, farPlane;// 获取近和远裁剪平面的值double fovY = 1;double aspectRatio = 0.5;projectionMatrix.getPerspective(fovY, aspectRatio, nearPlane, farPlane);farPlane = 1.9;double tanFovY = tan(fovY * 0.5);double tanFovX = tanFovY * aspectRatio;// 近裁剪平面的四个顶点(*vertices)[0] = osg::Vec3(0.0, 0.0, 0.0);(*vertices)[1] = osg::Vec3(tanFovX * nearPlane, tanFovY * nearPlane, -nearPlane);(*vertices)[2] = osg::Vec3(-tanFovX * nearPlane, tanFovY * nearPlane, -nearPlane);(*vertices)[3] = osg::Vec3(-tanFovX * nearPlane, -tanFovY * nearPlane, -nearPlane);(*vertices)[4] = osg::Vec3(tanFovX * nearPlane, -tanFovY * nearPlane, -nearPlane);// 远裁剪平面的四个顶点(*vertices)[5] = osg::Vec3(tanFovX * farPlane, tanFovY * farPlane, -farPlane);(*vertices)[6] = osg::Vec3(-tanFovX * farPlane, tanFovY * farPlane, -farPlane);(*vertices)[7] = osg::Vec3(-tanFovX * farPlane, -tanFovY * farPlane, -farPlane);(*vertices)[8] = osg::Vec3(tanFovX * farPlane, -tanFovY * farPlane, -farPlane);// 设置视锥体的边线osg::ref_ptr<osg::DrawElementsUInt> edges = new osg::DrawElementsUInt(osg::PrimitiveSet::LINES, 24);// 给edges数组添加顶点索引来定义边线edges->push_back(0); edges->push_back(1);edges->push_back(0); edges->push_back(2);edges->push_back(0);edges->push_back(3);edges->push_back(0);edges->push_back(4);edges->push_back(1);edges->push_back(2);edges->push_back(3);edges->push_back(4);edges->push_back(1);edges->push_back(4);edges->push_back(2);edges->push_back(3);edges->push_back(0 );edges->push_back(1 + 4);edges->push_back(0 );edges->push_back(2 + 4);edges->push_back(0 );edges->push_back(3 + 4);edges->push_back(0 );edges->push_back(4 + 4);edges->push_back(1 + 4);edges->push_back(2 + 4);edges->push_back(3 + 4);edges->push_back(4 + 4);edges->push_back(1 + 4);edges->push_back(4 + 4);edges->push_back(2 + 4);edges->push_back(3 + 4);/*edges->push_back(0);edges->push_back(7);edges->push_back(0);edges->push_back(8);*/// 其他边线的索引添加类似的操作...// 设置几何体属性geometry->setVertexArray(vertices);geometry->addPrimitiveSet(edges);geode->addDrawable(geometry);return geode;
}osg::ref_ptr<osg::Geode> createPyramid() {osg::ref_ptr<osg::Geode> geode = new osg::Geode();osg::ref_ptr<osg::Geometry> geometry = new osg::Geometry();// 顶点数组osg::ref_ptr<osg::Vec3Array> vertices = new osg::Vec3Array;vertices->push_back(osg::Vec3(0.0f, 0.0f, 1.0f));  // 顶点vertices->push_back(osg::Vec3(1.0f, 0.0f, -1.0f)); // 底面顶点1vertices->push_back(osg::Vec3(-1.0f, 0.0f, -1.0f)); // 底面顶点2vertices->push_back(osg::Vec3(0.0f, 1.0f, 0.0f)); // 底面顶点3vertices->push_back(osg::Vec3(0.0f, -1.0f, 0.0f)); // 底面顶点4// 设置几何体的顶点geometry->setVertexArray(vertices.get());// 底面索引数组osg::ref_ptr<osg::DrawElementsUInt> baseIndices = new osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLES);baseIndices->push_back(1);baseIndices->push_back(2);baseIndices->push_back(3);baseIndices->push_back(2);baseIndices->push_back(1);baseIndices->push_back(4);baseIndices->push_back(3);baseIndices->push_back(2);baseIndices->push_back(4);baseIndices->push_back(1);baseIndices->push_back(3);baseIndices->push_back(4);// 侧面索引数组osg::ref_ptr<osg::DrawElementsUInt> sideIndices = new osg::DrawElementsUInt(osg::PrimitiveSet::TRIANGLES);sideIndices->push_back(0);sideIndices->push_back(1);sideIndices->push_back(2);sideIndices->push_back(0);sideIndices->push_back(2);sideIndices->push_back(3);sideIndices->push_back(0);sideIndices->push_back(3);sideIndices->push_back(4);sideIndices->push_back(0);sideIndices->push_back(4);sideIndices->push_back(1);// 添加底面和侧面索引geometry->addPrimitiveSet(baseIndices.get());geometry->addPrimitiveSet(sideIndices.get());geode->addDrawable(geometry.get());return geode;
}osg::ref_ptr <osg::Geode > cteateQuad()
{//创建一个叶节点对象osg::ref_ptr <osg::Geode > geode = new osg::Geode();//创建一个几何体对象osg::ref_ptr <osg::Geometry >geom = new osg::Geometry();//添加顶点数据 注意顶点的添加顺序是逆时针osg::ref_ptr <osg::Vec3Array >v = new osg::Vec3Array();//添加数据v->push_back(osg::Vec3(0, 0, 0));v->push_back(osg::Vec3(1, 0, 0));v->push_back(osg::Vec3(1, 0, 1));v->push_back(osg::Vec3(0, 0, 1));//设置顶点数据geom->setVertexArray(v.get());//创建纹理订点数据osg::ref_ptr <osg::Vec2Array >vt = new osg::Vec2Array();//添加纹理坐标vt->push_back(osg::Vec2(0, 0));vt->push_back(osg::Vec2(1, 0));vt->push_back(osg::Vec2(1, 1));vt->push_back(osg::Vec2(0, 1));//设置纹理坐标geom->setTexCoordArray(0, vt.get());//创建颜色数组osg::ref_ptr <osg::Vec4Array >vc = new osg::Vec4Array();//添加数据vc->push_back(osg::Vec4(1, 0, 0, 1));vc->push_back(osg::Vec4(0, 1, 0, 1));vc->push_back(osg::Vec4(0, 0, 1, 1));vc->push_back(osg::Vec4(1, 1, 0, 1));//设置颜色数组geom->setColorArray(vc.get());//设置颜色的绑定方式为单个顶点geom->setColorBinding(osg::Geometry::BIND_PER_VERTEX);//创建法线数组osg::ref_ptr <osg::Vec3Array >nc = new osg::Vec3Array();//添加法线nc->push_back(osg::Vec3(0, -1, 0));//设置法线geom->setNormalArray(nc.get());//设置法绑定为全部顶点geom->setNormalBinding(osg::Geometry::BIND_OVERALL);//添加图元geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS, 0, 4));//添加到叶子节点geode->addDrawable(geom.get());return geode.get();
}int main() {// 创建场景图和视图器osg::ref_ptr<osg::Group> root = new osg::Group();osgViewer::Viewer viewer;// 创建四棱锥体几何体osg::ref_ptr<osg::Geode> pyramid = createCameraFrustum(viewer.getCamera());// 将四棱锥体添加到场景图中root->addChild(pyramid);// 设置场景图到视图器并运行viewer.setSceneData(root);return viewer.run();
}

 

 

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