meshlab point cloud to mesh

• Point cloud normal vector: First, you need to ensure that the point cloud has calculated the normal vector. A point cloud without a normal vector will look very dark in meshlab. The way to calculate the normal vector refers to my blog
• Rebuild the face: the parameters are all default. After apply, you can see that the number of faces is not 0
• Check that the normal vectors are facing roughly the same direction:
  • If not (as shown in the figure below), the reconstructed mesh visualization will be very strange (black and white interlaced, because meshlab will use the normal vector when rendering, the one facing the viewpoint is white, and the one facing away from the viewpoint is black). We need to do the following
    • Adjust the viewpoint to the angle you want to view. The picture above is the angle I want to see
    • Select the face facing us (the angle between the normal vector and us is less than 90°): After the selection is completed, you can see that the white ones turned red
    • Then we flip twice: the first time all flips, that is, black to white, white to black; the second time only the selected face (that is, the white area that turned red in the previous step)
    • After the flip is complete, remove the "visual selection" button, and you can see that the entire mesh is all white
    • Finally, check the normal vector again: you can see that most of the normal vectors are facing the same direction