Why do 3D models from Blender show through in Unity?

Question

Unity

I transferred the model to unity, but it is transparent and the textures have moved out, what needs to be done to return it back?

Answer 1

In blender, check where the normals "look" for your model .

Must be outside. If this is not the case for all polygons, then you need to fix it:
1) in the same Edit Mode, select all polygons (horizontal key A)
2) press Alt + N and select recalculate to the outside (Recalculate Outside, or Shift + N)

And the textures (materials, in general) in the unit need to be recreated