When i export to "3D coat" frm maya by OBJ some there is some serious disturbance found.
But when i export the same OBJ to deep paint then the model shows no disturbance.it is perfectly all right with deep paint.But why so different?
[attached img no 1]

When i export to "3D coat" frm maya by FBX some there disturbance is found but less severe.
[attached img no 2]

Why this happen.

while rendering in houdini using OBJ causes black shades at random places.So, i used FBX whose output was good.

But why this happen?