How is grid_normal computed? about cvpr2020-sdfdiff

[YueJiang-nj]

I just used 2 vertices next to the target grid position. The next one minus the previous one, then divided by 2 * voxel size.
This is just used to compute normals on the grid. After getting all the normals on the grid, then we do trilinear interpolation.

[Kai-46]

Thanks for the replies. That aligns with what I was thinking. So in this case, each vertex normal uses sdf values of 6 adjacent vertices (front-behind, left-right, up-bottom), right? To compute the vertex normals for the 8 vertices of a voxel, one needs to use sdf values of a total 8x6-8x2=32 vertices?

[YueJiang-nj]

I think that's correct.

[Kai-46]

Thank you for confirming!