Controlling Subdivisions of Curve on Export

 From:  Michael Gibson
2986.8 In reply to 2986.7 
Hi snookD,

> I am also finding that using something like an arc
> I have to change the default viewport meshing angle
> from the default 10 to get a smooth line.

It's actually best to just not worry about that.

Don't worry about trying to make the real-time display perfectly smooth, because if you increase the display mesh angle to lower than 10 it will tend to make an extremely dense display mesh in other areas and take up a lot of memory.

NURBS are rather different than polygons - if you happen to see some roughness in the realtime display of a NURBS surface it does not actually mean that the surface is necessarily bad or rough, you are just seeing the display polygons.

Later on when you actually export to a mesh file, that is the point when you can crank up the density and produce a denser mesh if you want, don't try to do it just for the real-time display.

In the future I do want to add in some additional control to the display mesh generation, but the roughness that you see there is only a display artifact, just ignore it.

> Is this normal? It's as though moi isn't interpolating the arc.

Yes, it's normal - like I mentioned previously, it is something that can happen when only using an angular metric to control subdivisions, when you have a surface that is somewhat broad in size but only shallowly curved.

For export you have that "Divide larger than" parameter that you can use in addition to the angle parameter to make it subdivided more. There isn't currently an equivalent for display meshing, so just don't worry about it for display meshing.

> If I then start to add booleans etc then I have to then
> lower the viewport mesh angle to 2-3 in order to prevent errors.

Those are not actual "errors" in the surface data itself, they are just glitches in the quick visualization of the surface that is displayed in the viewport.

The display mesh is more oriented towards generating a result very quickly rather than trying to make something that is as smooth as possible. The export mesher is more focused on producing a better mesh.

> If this is normal then is there a way to rebuild curves in moi?

There is probably no need to rebuild it - just do not get so worried about any imperfections in the display mesh. It's trying to give you a quick visualization of your surface and not a "final quality" mesh result like the export process does.

I can tell you more specifics about if your model should be rebuilt or not if you can post the 3DM file for it instead of only a screenshot, it is a lot easier to analyze geometry in a 3DM file than just an image.

But my guess is that you do not need to rebuild it, just don't worry about the display mesh so much.

- Michael