Issues with Trim Command, Boolean Difference,

I’ve been scrolling and reading through the forum some many times now, really great community and support!
Hopefully someone can help me with a serious problem:

I’m trying to model a freeform carved surface which later will be sent to the milling cutter as well as rendered.
I’ve modelled some pipes (NURBS) in Rhino, then exported them as OBJ’s (meshed) and remodelled them with Maya.
Reimporting the pipes as one mesh, I want to either 1. split them in half and unite them with a plane; 2. trim the pipe mesh with the plane and then the plane with the pipes; 3. try using only boolean operations.

I’ve tried all of the above, nothing has worked so far. Either boolean union fails or Rhino freezes.

Here’s some pictures for clarity!


…already tried mesh repair, althoug it is valid.
rebuilt it anyway.

boolean operation (difference) with nurbs plane causes rhino to freeze, although, funnily, it is no heavy workload for my laptop. (performance issues software-wise?)

Hello - the mesh is full of self-intersections

for one thing - I’d say that will be tricky to fix, but on top of that, the grim truth is that Rhino’s mesh intersection tools are weak to begin with.


Thanks for the fast reply;
I was able to separate the individual pipes in maya just now, so when reimporting I get individual meshes instead of one big messy meshy (:wink: object.
I’ll now try to convert them back to NURBS and join them using boolean etc…
Splitting works now as well.

How would you go about uniting them with the surface plane?
I would need that for a nice rendering…

Hello - if you can get all the pipes split with the plane, I shouldn’t think, unless the material is transparent or something, that you need to join it to the plane at all for a clean rendering. If you must, then assuming the mesh pipes all connect with one another, then DupBorder, and probably do some cleanup on the resulting curves, then run SplitMeshWithCurve, probably many times, and get the plane cut up - throw away the parts that fall inside the pipes and Join the rest with the pipes…