Faceted Reflection

[Mokiki]

Heyho,
I'm currently asked to do a quick render job of a few car models which are provided by the client. These are cad models so the geometry is not optimal and the timeframe won't allow me to rebuild parts of the models. So I have a quick question concerning a reflection error I have.
On some parts the reflection gets really faceted and if some of the experts here could look at it and tell me if that's because of the geometry I'd appreciate that. My current lighting setup is just a vray plane from the side. I checked smoothing group etc. I'd really appreciate some help

[Dariusz Makowski (Dadal)]

Looks like geometry issue. Try smoothing it or if all else fail. The only way to smooth it more would be to use Vred subdivision tool which is able to smooth (somehow good +/- ) nurbs based triangles etc...

Good luck.

Thanks, bye.

[Mokiki]

Guess I have to work my way around it. Sorry for not making it clear in the first post. These models came from a cad program but I got them as obj so I can't really do any conversion myself. But still I appreciate the time you have taken to answer my post

[Dariusz Makowski (Dadal)]

You cant apply meshsmooth/turbosmooth on those models. The geometry will go mental. Or if they are not merged(separate faces) then u even in bigger trouble. The only way to smooth it that I know of is to use Vred.

[Guest]

You could try welding all the verts and then applying a smooth modifier?

[samuel_bubat]

Before your try anything else.. I´d ask the customer if he can provide some sort of nurbs format like igs/step/sat.
Usually those kind of data comes from software that can export these formats.

btw. the geometry looks smoothed and welded. It ´s just the topology that´s pretty bad.

[Mokiki]

Thanks for all the suggestions
Sadly the models I got are the only ones I can get. And for the door the vertices are welded there are other parts which are not but those are luckily not visible. Will have to try to fix those errors in post I think.

[instinct]

If you received them as obj, then you lost vertex normal data, which is crucial to get proper shading with CAX data. Sadly there is not much you can do about it besides getting the data WITH normal data, getting source data and tessellating yourself or rebuilding.

Regards,
Thorsten

[waaazoo]

Are you sure about the normals ? In maya we have something like "unlock normals", "set to face", and so on... sometimes I get very bad looking normals, and when I make such operations it's great again...
Another suggestion, export to Obj, and re-import... this helps sometimes !

[instinct]

You might be able to fix hickups in face or vertex normals, but you will not be able to reconstruct the additional information of vertex normals derived from the Nurbs or Solids data i'd say.

Regards,
Thorsten

[wxyz]

Breakout problematic areas and apply wrap-it?

[winberg]

To reset nomals, I often make a box - edit mesh this, and then attach the object in question to this object.
I am not sure if it wil fix this problem, but I guess its worth a try.

-Tom

[Morbid Angel]

You might be able to fix hickups in face or vertex normals, but you will not be able to reconstruct the additional information of vertex normals derived from the Nurbs or Solids data i'd say.

Regards,
Thorsten

This is true. The normal data from nurb tessellation is not the same as if you do unlock / set to face/ smoothing angle. But in this case, perhaps not in max, but in maya you can select those faces and apply custom normal smoothing....Actually having them welded does not matter, on such meshes its impossible to weld them, nurb planes usually tessellate in a different way, they dont attach to each other, but blend the surfaces via normal only.

[Mokiki]

Sorry for being silent had some other stuff to do. I really appreciate all the help you guys offered. In the end I just did a normal render and smoothed the reflection out in post. Will try to follow the suggestions in this thread on the next job I'm confronted with the same conditions