osg::Node获取所有面片顶点坐标索引的集合，所有面片纹理坐标索引的集合

可以使用以下代码来获取osg::Node中所有Drawable的顶点坐标索引和纹理坐标索引集合：

// 获取所有Drawable
osg::Node* node = ...;
osg::ref_ptr<osg::Group> group = node->asGroup();
if (group)
{
    osg::ref_ptr<osg::Node> child;
    osg::Drawable* drawable = nullptr;
    osg::Geometry* geometry = nullptr;
    osg::Vec3Array* vertices = nullptr;
    osg::Vec2Array* texcoords = nullptr;
    std::vector<unsigned int> vertexIndices;
    std::vector<unsigned int> texcoordIndices;

    for (unsigned int i = 0; i < group->getNumChildren(); ++i)
    {
        child = group->getChild(i);
        drawable = child->asDrawable();
        if (drawable)
        {
            geometry = drawable->asGeometry();
            if (geometry)
            {
                vertices = dynamic_cast<osg::Vec3Array*>(geometry->getVertexArray());
                if (vertices)
                {
                    // 获取顶点索引
                    osg::UIntArray* indices = dynamic_cast<osg::UIntArray*>(geometry->getPrimitiveSetList()[0]->getIndices());
                    if (indices)
                    {
                        for (unsigned int j = 0; j < indices->size(); ++j)
                        {
                            vertexIndices.push_back((*indices)[j]);
                        }
                    }
                }

                texcoords = dynamic_cast<osg::Vec2Array*>(geometry->getTexCoordArray(0));
                if (texcoords)
                {
                    // 获取纹理坐标索引
                    osg::UIntArray* indices = dynamic_cast<osg::UIntArray*>(geometry->getPrimitiveSetList()[0]->getIndices());
                    if (indices)
                    {
                        for (unsigned int j = 0; j < indices->size(); ++j)
                        {
                            texcoordIndices.push_back((*indices)[j]);
                        }
                    }
                }
            }
        }
    }
}

需要注意的是，此代码只适用于具有单个PrimitiveSet的Geometry。如果存在多个PrimitiveSet，需要对每个PrimitiveSet进行遍历并分别获取顶点和纹理坐标索引。