VIEW PORT

[M.Yasir69]

HI ! Dear friends sometime i am facing this problem when i import cad file to 3d max this happen i can't see correctly object while moving this object shows in broken mesh please check the attached file but after this difficulty  i attched to picture one in viewport and one after rendering please tell me this problem any soliton thanx in advance 

[RobH2]

It could be any number of things but a few to check are, flipped normals and bad smoothing groups. Also, CAD files are bad for having a ton of coincident vertices. Go to 'subobject vertices' and select them all. So a 'Weld' with a small number like 0.001 or something. See if your number of vertices reduces significantly. That might help. Otherwise, upload the file and I or someone can look at it and help you better. It's hard to tell from your capture images.