[3ds Max] After 3ds Max is exported to fbx, the normal line error and the solution to the disappearance of the smoothing group

Below is the model built with max

After exporting it as fbx, it becomes this ghost, all the smoothing is gone

I specifically went to the teacher to help me out for an afternoon, and finally found a quick solution

Just convert the quadrilateral structure into a triangular structure.

can turn around

There is also a quicker method, which is to export the model to stl first, and then export the stl to fbx

Because the stl model will be automatically converted to a triangular structure

The following is the guided model, which is beautiful again