在OpenGL中绘制两个点云之间的交点(Draw Intersection between two point clouds in OpenGL)

 我有两个相似的点云，由一个在空间中给定位置（x，y，z）的矢量定义，我想同时渲染两个云并评估它们之间的差异。 这是我第一次使用OpenGL的应用程序，所以我仍然没有太多掌握使用它。 
 
 我已经设法通过分别处理每个向量来渲染它们，例如： 
 
    glBegin(GL_POINTS);GLfloat green[] = { 0.f, 1.0f, .0f, alpha[1]/10 };
    glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, green);
    glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, low_shininess);
    //glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, mat_specular);
    for (std::vector<Point3D>::iterator moit = morig_cloud.begin(); moit != morig_cloud.end(); ++moit){
        if ((moit - f_cloud.begin()) % (ptd[1]) == 0){
            glVertex3f(moit->x, moit->y, moit->z);
        }
    }
    glEnd();
 
 但是，当我重叠两者时，生成的图像如下： 
 
 红色和蓝色云应该完美匹配。 有没有办法“合并”积分？ 也就是说，考虑到点位置匹配，我可以改变匹配位置的颜色吗？ 仅使用点进行渲染而不进行网格划分。 
 
 我尝试在渲染之前比较两个向量，但算法最终太慢了，因为点云太大了。 

I have two similar point clouds, defined by a vector with their given positions (x,y,z) in space, and I want to render both clouds simultaneously and evaluate the differences between them. This is my first application using OpenGL so I still have not much grasp using it.
 
I've managed to render both of them by processing each vector separately, such as:
 
    glBegin(GL_POINTS);GLfloat green[] = { 0.f, 1.0f, .0f, alpha[1]/10 };
    glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, green);
    glMaterialfv(GL_FRONT_AND_BACK, GL_SHININESS, low_shininess);
    //glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, mat_specular);
    for (std::vector<Point3D>::iterator moit = morig_cloud.begin(); moit != morig_cloud.end(); ++moit){
        if ((moit - f_cloud.begin()) % (ptd[1]) == 0){
            glVertex3f(moit->x, moit->y, moit->z);
        }
    }
    glEnd();
 
However, when I overlap both, the resulting image is as follows: 
 
Where both the red and the blue clouds are supposed to match perfectly. Is there any way to "merge" the points? That is, considering that the points position match, I can change the color for the matching locations? The rendering is done with points only without meshing.
 
I tried comparing both vectors before rendering but the algorithm ended up being too slow, as the point clouds are too big.

原文：https://stackoverflow.com/questions/23007263