NURBS Facetting

[Kevin McAllister]

What controls the smoothness of the edges of NURBS Surfaces? I have some surfaces that are showing a fair amount of facetting both in the design layers or in a sheet layer viewport. If you extract curves from them the results are perfectly smooth. The surfaces also display perfectly smooth in Rhino.

I have tried all of the options I know of. Controlling curves in VW has gotten very complicated over the last few version. They include -

Preferences>Edit>2D Conversion Resolution - I believe it only affects how 2D objects are displayed and can't get "baked" in to actual geometry

Preferences>3D>3D Conversion Resolution - I believe it affects how extrudes and other solids operations display geometry. Not baked in unless you convert to generic solids while at a specific resolution. It also defines the number of segments in a sweep.

View>Rendering>OpenGL Options>Detail - display only either on screen or for a sheet layer viewport

View>Rendering>Custom Renderworks Options>Curved Geometry - display only either on screen or for a sheet layer viewport

Section Viewport>Advanced Properties>Display>3D Conversion Resolution - affects the geometry generated in a section viewport specifically

And finally - Document Settings>Document Preferences>Display>Mesh Smoothing with Crease Angle - affects meshes document wide.

The documentation is poor, there's lots of mixed information in these forums, and I honestly don't understand why it can't be simpler (and all in one place). Other programs just work.

I've attached an example of the geometry I'm seeing. The pdf was created from a sheet layer with a viewport rendered in wireframe.

Kevin

[PVA - Admin]

You appear to have a comprehensive list of every setting I am aware of to change smoothness in Vectorworks. I agree that that is entirely too many and "Quality Settings" in general should be at the very least grouped together in one place, if not reduced to fewer options altogether.

If you render that viewport in Hidden Line or Final Quality RW, does the same faceting appear?

Could you post a sample file (with just one of those faceted NURBS surfaces in it) so that I can have a closer look?

[Kevin McAllister]

Hi Jim,

Here's a sample file.

The edge curves of the surfaces look the same in various render modes (examples on a sheet layer). I guess it could be because these surfaces were unwrapped by Rhino and imported. Its just really odd that parts of them extract into perfectly smooth curves.

I also wish the smoothness settings were clearly grouped - ones that affect display only, ones that affect physical geometry and ones that affect output (print or pdf).

Thanks for taking a look.

Kevin

[Benson Shaw]

Kevin, make a(nother) wish for smooth NURBS and other solids.

Great lists! All those resolution, smoothing options should be better organized and defined. Having these various access points to these features is OK, no need to remove them. But a new Nave Palette tab or Org Palette tab or some new palette/menu could be created to offer them all in one place.

Remember this thread?

http://techboard.vectorworks.net/ubbthreads.php?ubb=showflat&Main=35014&Number=172791#Post172791

Sweep was fine until holes subtracted. Then the horrendo jaggies appeared.

-B

[PVA - Admin]

Same here, the extracted geometry and exported geometry to other 3D formats all seems fine and smooth, but the originals are definitely faceted regardless of render/quality settings being maxed across the board. Submitting this as an issue now.

[Kevin McAllister]

This bug is causing all sort of trouble with using using NURBS from Rhino in construction drawings. The facetting seems even worse in PDFs.

Here's another example. It looks like some gnawed on it....

Kevin

Edited April 11, 2014 by Kevin McAllister

[Kevin McAllister]

I've done some more explorations. It seems to be linked to how VW imports NURBS shapes. I thought NURBS were calculated forms. Shouldn't they be identical in all software?

This facetting has managed to track its way through my entire workflow for a project all the way into C4D. It makes for some not so good drawings and renderings.

Kevin