EDIT After Victor T.'s suggestion (ignore seams):
I'm using elastic surface nets to convert a 3D voxels into a nice smooth mesh. The mesh part, is great, however, I can't seem to find a decent looking method of getting proper vertex normals for each voxel. I've been reading a couple of forums, like this one from reddit and this one from Stack Overflow. Using the method described in the stack overflow one, I got normals that looked like this:
While this might seem okay, it doesn't work very well with flat surfaces, and if I try to add methods for dealing with flat surfaces, it messes everything else up. And yet it still doesn't look ideal.
Using cross products of the vertices to get the normal, I was only able to get a hard shaded mesh, that did look decent, however, it can't distinguish up and down, so it doesn't look right in overhangs. It also is hardshaded, and I want smooth shading.
Question : What are ways I can achieve a better looking normal? What techniques are common for this? Is there any way modified methods I can use that are better than the ones I am doing? I am okay if the best looking method is expensive.
I can post source code if needed.
After Victor T.'s suggestion, I managed to get great looking surface normals! One problem, the corners don't look right, I was unable to find any correlation between why is the normals on the corners need to be flipped (0 - normal).