[question] confused by extract_mesh.ipynb, the dataset from img seems not be used?

[zydmtaichi]

hi, i read the code in extract_mesh.ipynb and noticed the var dataset in line 14 of cell 2 is not used in code below to export the colorless mesh. In my perspective, the var sigma which feeds to marching cube and then extract the mesh is created by linspace data from numpy. So the img data is actually not used in mesh exportation? pls give me some explain for this question, thanks

@kwea123