[3ds MAX] sometimes nurms surface gone weird

kimplate

hi, im making some stuff for kitbashing. but sometimes i adding nurms on my mesh, i bump into weird surfaces. 


left one is original mesh and i adding pipe by boolean. and some symmetry works.

but when i add nurms, right one has weird surfaces.

i thought left smooth edge is right result but something gone wrong.
i cant understand there's a problem in my poly shape or...another somewhere. somebody...help me?

huffer

Just prior to Turbosmoothing, convert to Editable Mesh and back to Editable Poly (if it's not fixed, reset xforms, attach it to a cube), it's a weird bug like that.

kimplate

oh. its fixed after Tsmooth 0 -> editable poly.
... still i cant understand how could this weird shape gonna happen! but thanks for advise!

monster

I wonder if selecting all faces in Editable Poly mode and pressing re-triangulate fixes this. Might be a quicker that way.

cptSwing

I think it's to do with broken normals somehow?