小编Joe*_*oey的帖子

我的任务:计算3D网格的像素坐标(例如制作快照),从特定的摄像机角度找到该网格的2D形状.

我目前正在使用带有QGeometryRenderer的Qt3D将包含网格的场景渲染到QWidget,它可以正常工作.我尝试使用QWidget :: render()将QWidget的内容呈现为Pixmap,如本文所建议的如何创建QWidget的屏幕截图？.将像素图保存为.jpg会产生具有默认背景颜色的空白图像,这是有意义的,因为QWidget本身并未保存网格对象.

以下是我在mainwindow.cpp中设置场景的方法

// sets the scene objects, camera, lights,...
void MainWindow::setScene() {
    scene = custommesh->createScene(mesh->getVertices(), 
            mesh->getVerticesNormals(), 
            mesh->getFaceNormals(), 
            mesh->getVerticesIndex(), 
            mesh->getFacesIndex());              // QEntity*                         
    custommesh->setMaterial(scene);              // CustomMeshRenderer object
    camera = custommesh->setCamera(view);
    custommesh->setLight(scene, camera);
    custommesh->setCamController(scene, camera);

    view->setRootEntity(scene);                  // Qt3DExtras::Qt3DWindow object

    // Setting up a QWiget working as a container for the view
    QWidget *container = QWidget::createWindowContainer(view);
    container->setMinimumSize(QSize(500, 500));
    QSizePolicy policy = QSizePolicy(QSizePolicy::Policy(5), QSizePolicy::Policy(5));
    policy.setHorizontalStretch(1);
    policy.setVerticalStretch(1);
    container->setSizePolicy(policy);
    container->setObjectName("meshWidget");

    this->ui->meshLayout->insertWidget(0, container);
}

至于渲染,这里是custommeshrenderer类,其中定义了QGeometryRenderer,并在初始化网格时返回QEntity*.

#include "custommeshrenderer.h"
#include <Qt3DRender/QAttribute>
#include <Qt3DExtras>
#include <Qt3DRender/QGeometryRenderer> …