Rhino problem splitting mesh Part 2

[MetropolisCNC]

If I have to rebuild the model inside Rhino can I do the following?

Import the model
Create about a dozen planes in x and y. Then create curves from the intersection of the planes and the model.

Then loft those cross sections together?

[chmillman]

Depending on the config of your model, that may or may not work well... or at all. if the object is simple, it might give you something usable.

Keep in mind the following:

You can use the function Contour from the Front viewport to create the sections without having to create the planes first.

The cross sections obtained from your intersections will be polylines, not smooth curves. Lofting them will create a polysurface object of many facets, which will be extremely heavy and probably as unworkable as the mesh. So you will need to rebuild the curves to be smooth NURBS splines first, preferably with as few control points as possible.

Ideally, when you Loft, you would like to have all the curves have a similar structure and the same number of control points. You can also try the rebuild option inside the command. In Loft, you don't have much control over what happens between the sections, but if you have enough it should be OK.

At the "top" and "bottom" you are going to have either openings (the curves are closed) or if you loft to points at the start and end, you will have poles. You will need to manage those correctly.

HTH, --ch

[MetropolisCNC]

Tried this way too with contour and loft. Rhino choked again.

I tried Max and Maya at school they both didn't like my OBJ file, and it seems Maya can only split a mesh with a flat plane.

I have Solidworks student edition and tried that no luck.

I'm going to DL Blender today and try to figure that one out. If that doesn't work I'm screwed I think.

I'm not sure if ZBrush even has an option to do what I want.

[chmillman]

When you say Rhino "choked" what do you mean? In principle if you do it correctly, Rhino should not fail to make a surface there. Whether it has enough detail or not for you is another matter (NURBS surfaces are inherently smooth and are not good at doing highly textured objects like meshes are). But your curves need to be correct in order for Rhino to make a good surface in any case.

Otherwise, you need a specialized mesh editing tool like Magics to deal directly with the mesh. I'm not going to tell you how much that costs... --ch

[MetropolisCNC]

I only lofted in one direction. There were probably 15 curves altogether and it twisted it in a few spots, but after the style box I hit ok and it just hanged there.

I reopened and tried again this time lofting only a few curves and Rhino twisted them. I think this part has to do with my direction as some of the curves are on the same plane.

The problem I can see happening already is even if this does work there are too many areas that will end up being flat after the loft that I won't be able to correct I don't think. This is the reason I used ZBrush in the first place.

[chmillman]

The problem I can see happening already is even if this does work there are too many areas that will end up being flat after the loft that I won't be able to correct I don't think. This is the reason I used ZBrush in the first place.

Likely. There is just so much that one can do with NURBS surfaces in terms of textures, and converting from mesh to NURBS is not an easy thing. --ch