What to do if half of the model disappears when exporting from Blender 2.8?

Question

Unity

Hello, the problem occurs when exporting a model from Blender 2.8 to Unity 5. Half of the model disappears. How can I fix this and what is my mistake?

Answer 1

Not half of the model disappears, the back side of the face (polygon) is "cut off" by the shader.
You have all the normals inverted to make sure you enable this option, red is the back side, blue is the front side.
To flip normals selected in edit mode Alt+N -> Flip.

Answer 2

Try to apply all the modifiers (for example, there may be problems due to rotation), and then move. You can also check the quality of the mesh in edit mode after that (boolean can cause problems).