FBX from 3ds is mission poly's

When i imported a mesh from 3ds max 2019, the mesh has missing poly’s. I’ve tried to fix it myself but i dont know why it’s doing this. I’ve imported other meshes in other projects with no problems. The mesh i’m trying to import was created using the topology tool in 3ds max. The model in max doesn’t have any holes in it.alt text

you probably have some inverted normals. if you open the mesh in unreal engine theres a option along the top to show normals (i dont have the editor open right now so i cant tell you the procedure). another option to check normals in unreal is to place the mesh in the level, scale it up, and orient your camera on the inside of the mesh and look at the bits where there was holes. if you can see faces from the inside you know that the normals are inverted. to fix the normals you will need to affect them in your modeling software. i dont work with max so i cant tell you how to do it, but in blender theres a few ways which include selecting the faces pressing W and selecting flip normals, and theres also selectinfg the mesh then going to the mesh tab then normals and then selecting either recalculate inside or recalculate outside. im sure max must have some similar options.