Additional file formats ...

Please consider adding:
PLY - 3d scanning data, with vertex color, import and export
STL - 3d printing, import and export

I would not mind if this was available, but is this really worth making IStonia work?
Most prototyping services accept .obj nowadays. Both requested formats can be converted in free software, such as Meshlab for Import to – and after exports from Nvil. There's not the slightest useful thing one could do with vertex colours inside Nvil – so why include this feature? Neither is there texture painting, nor baking textures to vertex-colour capabilities available – preconditions to make Vertex color support meaningful. Again something one can do even in free apps, such as Blender.

While there are free applications to convert formats, most people are concerned about workflow. Import/Export though multiple applications surely has an impact on workflow.

OBJ format is not economical for large files. Data is stored as text, and although it does compress well, it is an additional step. The web platforms that display 3D files typically do not uncompress files in order to view them, so its a benefit to using a format that has efficient data storage.

In regards to vertex color, I don't think adding the tools necessary to do the texturing would be needed, because as you say, Blender can do this. Allowing the vertex color to imported/exported would allow for using the texture as a modeling reference, or for some simple editing, provided it did not destroy the color information.

Well. I consider quick format conversion before loading into or after saving out of Nvila non issue – this can also happen via Cipboard saving. Have you tried this out?
The reality is that Nvil can not stand alone anyway, regardless of output goal one will always need one or more other apps to exchange the work geometry with. When touching Import/ Export I personally would find more beneficial to support a file format which lets users bring Curves in and out of Nvil.

In regards to vertex color, I don't think adding the tools necessary to do the texturing would be needed, because as you say, Blender can do this.

Early versions of Voidworld did have the ability to save vertex colors to a texture. The help file states that the ability is still there "Help > Modeling > Vertex section > Mesh Vertex > Vertex color"
 

Allowing the vertex color to imported/exported would allow for using the texture as a modeling reference, or for some simple editing, provided it did not destroy the color information.

Nvil will import/export vertex colors using the .dae file format.

steve,

I'm not sure if 3d scanning apps have implemented DAE format universally, as that format has the most significant benefit for animation.

Passing along the existing vertex color would be fine, without exporting/converting to a texture map.

polyxo,

The files I work with are often 200 - 300mb or more. It would definitely save me some time if no conversion were needed.

I'm not sure about the clipboard function, have to check on that. Thanks for the suggestion.