Help converting a mesh to nurbs

Hi @Cosmas, yes, I tried this, but it just makes individual planes out of each polygon. I’m looking for something that will be able to interpret the overall shape of the form. perhaps I’m asking to much hehe ! I’ll post you a pic

thanks @davidcockey, I’ll look into this method

interesting method you came up with @mcramblet, this is something I’d like to try. do you have any information about converting to NURBS with T-Splines…any tutorials you know of?

that’s a smart auto-fillet method you invented @mcramblet. nice. but i’m still not clear about what your steps are…so you bring your quad mesh into Rhino, and then you convert to T-splines, and then Nurbs…?

This is great. I’m very interested in this technique. I’ve kept an old copy of 3D Max with nPower Translator installed so I can quad mesh (roughly) my nurb imports. nPower’s pluggin was the only available quad mesher for nurbs I had. It was great for quick and dirty auto fillets around very small type. I see with your example a perfect application for it.

So you export tris from Rhino? To zBrush and export quads from there. How accurate/effective is the remesher in ZBrush?

Please explain more and any limitations you have come across. Maybe I can finally retire my old, old workstation with 3D Max 5.x.

Thanks.
Paul

Here is a very quick “example”, without taking any time to make adjustments. I can get more detailed later, if needed:

Rhino object:

Meshed in Rhino:

Imported into ZBrush:

DynaMeshed to convert into dense quads:

ZRemesher to convert into lower poly quads:

Imported quad mesh into rhino, converted to T-Splines object (toggled smooth):

T-Splines object converted to NURBS:

Rendered NURBS object in Rhino:

There are steps in ZBrush that allows for control as to how much smoothing takes place and a couple of methods to get ZBrush to better work with the triangled mesh from Rhino. The ZRemesher seems to do an amazing job at creating good quality quad meshes. Getting something smooth is easy, I’m trying to play with settings and methods to see how much detail I can capture when coming out of ZBrush and that appears to be a little harder. Still working on that portion of it.

3 Likes

What resolution is your Dynamesh in ZBrush (before you create a standard mesh from it)?
How many quads are you typically running through T-Splines?

I haven’t developed any hard and fast rules, at this point. For the Dynamesh, I’ve used in the 300-500 range for the resolution. In the example used earlier in the thread, the mesh from ZBrush was running close to 14,000 polygons and converted with very little lag with T-Splines. I’m just scratching the surface of the potential and I hope to dig deeper into it in the next few weeks.

This is great…thanks very much!

That’s good to know for comparison. I have not downloaded ZB 4R7 or the documentation yet. I think Dynamesh could be really useful for some of the work I am doing. I would like to see how Dynamesh is working with subtools also. I thought that all the subtools had to fit into into the overall Dynamesh resolution, so it was not possible to have one subtool with a higher resolution than another, but maybe I’m wrong there.

I’m not sure about subtool resolution. I’m a ZBrush newbie and know about enough to be dangerous, at this point. I’m trying to learn it, though.

This a fantastic example. Thank you for sharing it!

Of course, my immediate second thought is that it would be WONDERFUL if Rhino 6 could do this type of intelligent mesh-smoothing in version 6 … without having to monkey around :monkey: with Z-Brush at all. Any McNeel thoughts on the matter?

2 Likes

I’ve been trying to learn it for a long time, and I’ll admit I’ve been a ZBrush newbie for about 14 years. :smile:

1 Like

Well, that remeshing is not just some remeshing. There’s only less than a handful of programs which do offer intelligent quad remeshing at all… the killer feature for those who want to make highly detailed sculpted models available in Games. In each of these apps it took years to get there even as a high priority feature and what Zbrush offers in this respect simply plays in another league when compared to other implemetations. I guess it save to say that seing this sort of remeshing from arbitry meshes as seen here is rather unlikly for V6. That doesn’t mean that one couldn’t profit in numerous other ways from mesh smoothing.

I tried this sort of thing with 3DCoat and it sort of worked with that software, too. For whatever reason, I just couldn’t get the hang of 3DCoat, it just has a very odd interface. Not that I know much of ZBrush at this point, but I can at least get around a bit and it makes sense. 3DCoat is just plain weird to me and I struggled to do anything in that software. I don’t think it does nearly as good of a job creating quad meshes, at least in my limited experience.

1 Like

Max Smirnov, on the MoI forums wrote a couple scripts for MoI. One to import polygon objects and one to convert them to nurbs. Here’s the link if you want to check it out:
http://moi3d.com/forum/index.php?webtag=MOI&msg=6674.162

MoI reads and writes Rhino 5 files.

Hi I’ve followed your steps but I’m having a bit of trouble going from t-spline surface to nurbs. Attached above is the t-spline surface after the tsConvert and tsSmoothToggle command. After that, I’m unable to convert it into a mesh using the MeshtoNURB command. It did not allow me to select the t-spline mesh object. Any idea what I’m missing?

Ivan

You want to use the Convert to Rhino Object, to get a NURBS object from a TS surface.

OH yes of course! I actually did that yesterday and didn’t realize that it outputs a NURB surface. No wonder why it didn’t allow me to convert it :sweat:

Thanks mcramblet

I see if the original mesh has distortions, then NURBS takes over them :confused:
2018-08-05_092210