Wrong face normal vector and "zigzag" issue

[LiuXinqi12]

Hi, great work and thanks for sharing!
I meet some problems when I tested this method. I found that when reconstructing a surface with UNDC using a point cloud as input, the output always surffer from wrong face normals and obvious "zigzag" issues, even I use the default input parameters(python main.py --test_input examples/tshirt.ply --input_type pointcloud --method undc --postprocessing --point_num 8192 --grid_size 128
).
I don't know if this is common? In addtion, are there any suggestions to improve the reconstrution quality? Thanks a lot!

[czq142857]

This is common. So double-sided rendering is always required. Besides, the face normals cannot be consistently oriented in the mobius strip.

[LiuXinqi12]

Well, thanks very much for your help！

[legel]

Great work, overall.

Transferring the normals from the 3D points to the face normals is definitely an important problem to solve. This is because other major downstream applications require this knowledge and may not work properly without it.

I figure we could take a stab at trying to interpolate the directions from point normals into the final assumed directions from face normals, but one difficulty I'm having is with the difference in 3D coordinate systems from the start to the end.

Here is what I mean:

Before NDC:
  Min, Max for X: [-0.10100799798965454, 0.10499099642038345]
  Min, Max for Y: [-0.3853279948234558, -0.18277700245380402]
  Min, Max for Z: [-0.42232999205589294, -0.18158100545406342]
After NDC:
  Min, Max for X: [1.285664677619934, 383.6967468261719]
  Min, Max for Y: [0.6957769989967346, 377.27813720703125]
  Min, Max for Z: [0.704517126083374, 448.9361572265625]

Is there any way we can preserve or chain through the original coordinate system into the final output (x,y,z) values for the mesh from noisy point cloud inputs?