New Rhino / Cinema 4D Import / Export Plugin announced

 From:  Michael Gibson
3642.12 In reply to 3642.8 
Hi Stefan, well your comments seemed to say that you were having shading problems with MoI's OBJ export.

I was surprised to read that, since I have not heard any mention of such problems going into Cinema4D and I have not received any bug reports or anything from you about that issue.

It seems strange that so many other people are able to transfer data from MoI into Cinema4D without any shading glitches in the slightest.

Do you possibly have any example file that you could post that would show what you were describing?

Maybe you ran into an n-gon triangulation error in Cinema4D. If that was the case, for that particular file you could use "Output: Quads & Triangles" when saving the OBJ from MoI to make MoI triangulate the n-gon instead of it happening in C4D. Generally C4D is very good at dealing with n-gons, but that is the one area where it will do some fairly complex additional processing on import.

> it is very true that the tessellation engine is much better in MOI
> (i would wish rhino had a similar), but also the rhino tessellation
> does its job and provides internally good meshes for render

Actually a lot of people find this to be not true at all - for example see this person's blog post:

Notice there how Rhino put in a kind of large flat polygon in an area that should be rounded? That's one of the most common meshing glitches that people often run into with Rhino, that one also impacts the shape of the mesh considerably and is noticeable in renders.

> also it keeps all layers, blocks, hierarchical structures,
> materials cameras, lights, etc.

Certainly this part could be useful to many people.

But it is confusing to me why you would claim to get better shading along with that - especially if all you are transferring is quads and triangles and there is no n-gon processing going on, then the exact same vertex normals will be transferred using OBJ format.

Why do you think the vertex normals that you are accessing are somehow better than the ones that are transferred by OBJ? Normals are normals.... it is confusing to me why you would think that you somehow have "better normals" or something like that.

> i asked you that many month before some time ago. you
> said you had no plans to do so due to some limitations you
> see in the 3dm file, that might e true of course.

Well yes, it is true - 3DM format is not the ideal place to store mesh data because it is limited in several ways, see this previous post for some examples:

But my main concern is that you mention shading problems where I have not heard of any such problems from other users. If you could give any example file that demonstrates those problems, it would help me understand what you may have been running into.

That's actually one of the nice things about Cinema4D - specifically that it reads vertex normals from OBJ files so that you get the exact same shading as was seen on the NURBS surface.

- Michael