osgearth3.2绘制云的代码，支持云厚度和颜色的调整功能

以下是使用osgEarth 3.2绘制云的代码示例，支持云厚度和颜色的调整功能：

#include <osgEarth/MapNode>
#include <osgEarthUtil/SkyNode>
#include <osgEarthUtil/Controls>

using namespace osgEarth;
using namespace osgEarth::Util;
using namespace osgEarth::Util::Controls;

// 定义绘制云的函数
void drawCloud(osg::Group* root, float thickness, const osg::Vec4& color)
{
    // 创建一个平面，用于绘制云
    osg::ref_ptr<osg::Geometry> geom = new osg::Geometry();
    osg::ref_ptr<osg::Vec3Array> vertices = new osg::Vec3Array();
    vertices->push_back(osg::Vec3(0.0f, 0.0f, 0.0f));
    vertices->push_back(osg::Vec3(1.0f, 0.0f, 0.0f));
    vertices->push_back(osg::Vec3(1.0f, 0.0f, 1.0f));
    vertices->push_back(osg::Vec3(0.0f, 0.0f, 1.0f));
    geom->setVertexArray(vertices.get());

    osg::ref_ptr<osg::Vec4Array> colors = new osg::Vec4Array();
    colors->push_back(color);
    geom->setColorArray(colors.get());
    geom->setColorBinding(osg::Geometry::BIND_OVERALL);

    osg::ref_ptr<osg::DrawElementsUInt> primitive =
        new osg::DrawElementsUInt(osg::PrimitiveSet::QUADS, 0);
    primitive->push_back(0);
    primitive->push_back(1);
    primitive->push_back(2);
    primitive->push_back(3);
    geom->addPrimitiveSet(primitive.get());

    // 创建材质属性
    osg::ref_ptr<osg::Material> mat = new osg::Material();
    mat->setAmbient(osg::Material::FRONT_AND_BACK, osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f));
    mat->setDiffuse(osg::Material::FRONT_AND_BACK, osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f));
    mat->setAlpha(osg::Material::FRONT_AND_BACK, color.a());

    // 创建节点
    osg::ref_ptr<osg::Geode> geode = new osg::Geode();
    geode->addDrawable(geom.get());
    geode->getOrCreateStateSet()->setAttributeAndModes(mat.get(), osg::StateAttribute::ON);
    root->addChild(geode.get());

    // 设置云的厚度
    osg::ref_ptr<osg::Uniform> thicknessUniform = new osg::Uniform("thickness", thickness);
    geode->getOrCreateStateSet()->addUniform(thicknessUniform.get());
}

int main(int argc, char** argv)
{
    // 创建地图节点
    osg::ref_ptr<MapNode> mapNode = MapNode::create();
    osg::ref_ptr<SkyNode> skyNode = SkyNode::create(mapNode.get());
    osg::ref_ptr<osg::Group> root = new osg::Group();
    root->addChild(mapNode.get());
    root->addChild(skyNode.get());

    // 创建调整工具栏
    osg::ref_ptr<HBox> toolbar = new HBox();
    osg::ref_ptr<Label> thicknessLabel = new Label("Thickness:");
    thicknessLabel->setMargin(5.0f);
    osg::ref_ptr<HSliderControl> thicknessSlider = new HSliderControl(1.0f, 10.0f, 1.0f);
    thicknessSlider->setWidth(150.0f);
    thicknessSlider->addEventHandler(new ControlValueChangedHandler([&](Control* control) {
        drawCloud(root.get(), thicknessSlider->getValue(), osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f));
    }));
    osg::ref_ptr<Label> colorLabel = new Label("Color:");
    colorLabel->setMargin(5.0f);
    osg::ref_ptr<ColorPickerControl> colorPicker = new ColorPickerControl();
    colorPicker->setColor(osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f));
    colorPicker->addEventHandler(new ControlValueChangedHandler([&](Control* control) {
        drawCloud(root.get(), thicknessSlider->getValue(), colorPicker->getColor());
    }));
    toolbar->addControl(thicknessLabel.get());
    toolbar->addControl(thicknessSlider.get());
    toolbar->addControl(colorLabel.get());
    toolbar->addControl(colorPicker.get());

    // 绘制云
    drawCloud(root.get(), thicknessSlider->getValue(), colorPicker->getColor());

    // 创建视图
    osgViewer::Viewer viewer;
    viewer.setSceneData(root.get());
    viewer.getCamera()->setClearColor(osg::Vec4(0.2f, 0.2f, 0.6f, 1.0f));
    viewer.getCamera()->setProjectionMatrixAsPerspective(
        30.0f, static_cast<double>(viewer.getCamera()->getGraphicsContext()->getScreenWidth()) /
        static_cast<double>(viewer.getCamera()->getGraphicsContext()->getScreenHeight()), 1.0f, 1000.0f);
    viewer.setUpViewInWindow(50, 50, 800, 600);
    viewer.addEventHandler(new osgViewer::StatsHandler());
    viewer.addEventHandler(new osgViewer::WindowSizeHandler());
    viewer.addEventHandler(new osgViewer::ThreadingHandler());
    viewer.addEventHandler(new osgViewer::LODScaleHandler());
    viewer.addEventHandler(new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()));
    viewer.addEventHandler(new osgViewer::RecordCameraPathHandler());
    viewer.addEventHandler(new osgViewer::ScreenCaptureHandler());
    viewer.addEventHandler(new osgViewer::HelpHandler());
    viewer.addEventHandler(new osgViewer::StatsHandler());
    viewer.addEventHandler(new osgViewer::WindowSizeHandler());

    // 运行程序
    return viewer.run();
}

在上述代码中，我们定义了一个名为`drawCloud`的函数，用于绘制云。该函数接受三个参数：

- `root`：云节点的父节点。
- `thickness`：云的厚度。
- `color`：云的颜色。

在函数中，我们创建了一个平面作为云的形状，设置了材质属性和颜色，并将它们添加到了云节点中。在最后，我们将云的厚度设置为指定的值。

在主函数中，我们创建了一个地图节点和一个天空节点，并将它们添加到根节点中。然后，我们创建了一个调整工具栏，其中包含一个滑块和一个颜色选择器，用于调整云的厚度和颜色。我们使用`drawCloud`函数绘制了一个初始的云，并将它添加到根节点中。最后，我们创建了一个视图并运行程序。

你可以根据自己的需求调整代码，实现你想要的效果。