Question

我在Qt项目中使用libQGL来制作点云查看器。问题是，随着更多点（超过300.000），与查看器（旋转，平移，缩放）的交互很慢。我该如何解决这个问题？

Answer 1

在缩放/平移/旋转时渲染较少的点。渲染点云时，您可以通过将顶点属性缓冲区的步幅乘以3

来渲染每三个点

（使用QOpenGLShaderProgram方法）

void PointCloud::paintGL(){
    glClear (GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT|GL_STENCIL_BUFFER_BIT);
    pointProgram->bind ();
    points.bind ();
    if(transforming){
        pointProgram->setAttributeBuffer (pointLoc, GL_FLOAT, offsetof (PointStruct, data), 3,sizeof(PointStruct)*3);
    } else {
        pointProgram->setAttributeBuffer (pointLoc, GL_FLOAT, offsetof (PointStruct, data), 3,sizeof(PointStruct));
    }
    CHECK_GL_ERR;

    if(transforming){
        pointProgram->setAttributeBuffer (pointCol, GL_FLOAT, offsetof (GrabberPointXYZIT,color), 3,sizeof(GrabberPointXYZIT)*3);
    } else {
        pointProgram->setAttributeBuffer (pointCol, GL_FLOAT, offsetof (GrabberPointXYZIT,color), 3,sizeof(GrabberPointXYZIT));
    }
    CHECK_GL_ERR;
    pointProgram->enableAttributeArray (pointLoc);
    pointProgram->enableAttributeArray (pointCol);
    pointProgram->setUniformValue (mvpLoc, pMat*vMat);

    glDrawArrays (GL_POINTS,0, numPoints);
    CHECK_GL_ERR;


    pointProgram->release ();
    points.release ();
}

Qt应用程序中的libQGL

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