Sudden triangles in viewport and render

[EnterR]

Hello,

 

The model is exported from ArchiCAD to .3ds and imported to MAX. I did a lot of post modeling, rendering and other work in MAX before this happened: I noticed some surfaces are divided into triangles in the render (VRay) and in the viewports.

 

Only one object is showing triangles in the viewport. Still, the objects showing triangles in the rendering are different ones.

 

The normals are OK, no coplanar faces. Tried restarting MAX. Tried changing viewport and graphics driver settings. No smoothing modifier is applied.

 

I may be getting paranoid, but I am also noticing that at the same time of this triangulation the round looking columns in the scene started to look like they've lost iterations and gotten chamfered.

 

According to the VRay messages the model has ~300 000 faces. I've had no problems with the file so far, except MAX crashing every now and then.

 

Any ideas?

[hughie]

looks like you have covered the usual suspects, have you checked the smoothing groups? unsure quirks from Archicad but you could check to see if all the verts came in welded together.

[EnterR]

Found the problem: all edges of one object were (accidentally?) set to "Visible" in the Editable Mesh -> Surface properties.

 

Solution: selected all edges and pushed "Auto Edge" in same rollout, which made all the "internal" edges invisible.

[XITIJ412]

Pls.find here with attachment.

I hop now problem will be solved.