MAXIMUM frustration


#1

Hello again:

My frustration level is now at MAX.

All I want to do, is cut a model into two pieces, with WIRECUT.
The other day, I attempted to perform an illegal operation, which was to try to cut a meshed object. I then used the MeshtoNURB command to convert it, so I could cut it. I then went back to the original file, made copies of it again, and did the operation again on a copy, just like I did the first time. When I selected it, only the top half selected. The top half was where I had put the cut line in the first place. (but it wasn’t cut) I NEVER used the original file to work with….I’ve always used and worked with a copy of it.

I could never delete the bottom half, which I do not want to keep. So I tried WIRECUT again on the next copy. It went through a bunch of stuff, but it still wasn’t cut. I tried to copy it, and then the program hung up, with a “Not responding” message. After trying this several more times, I had to WARM-BOOT the machine. On a successive try, I had to COLD-BOOT the machine.

I have contacted the maker of the model, to see what he can do about it. RhinoV5 does not appear to be able to do the wirecut. I have been screwing around with this all day, and accomplished exactly NOTHING……


#2

@Karl_Starke, if possible please upload the model and indicate with a plane or line where you wanted to cut it and which side to keep. _WireCut does not work on mesh objects but if you want to split a mesh you may try _MeshSplit with a plane, this plane can be a nurbs object too.

c.


(David Cockey) #3

[quote=“Karl_Starke, post:1, topic:46029”]
The other day, I attempted to perform an illegal operation, which was to try to cut a meshed object. I then used the MeshtoNURB command to convert it, so I could cut it. I then went back to the original file, made copies of it again, and did the operation again on a copy, just like I did the first time. When I selected it, only the top half selected. The top half was where I had put the cut line in the first place. (but it wasn’t cut)[/quote]Did you read my response to your earlier post about this problem? MeshToNURB creates a polysurface based on the mesh, and also leaves the mesh in place. Did you delete the mesh? If not when you used MeshToNURB you selected the polysurface which was cut, but the mesh was also there and not cut. The part which isn’t split is probably the original mesh.

[quote=“Karl_Starke, post:1, topic:46029”]
I then went back to the original file, made copies of it again, and did the operation again on a copy, just like I did the first time. When I selected it, only the top half selected. The top half was where I had put the cut line in the first place. (but it wasn’t cut) I NEVER used the original file to work with….I’ve always used and worked with a copy of it.

I could never delete the bottom half, which I do not want to keep. So I tried WIRECUT again on the next copy.
[/quote]When you open a file in Rhino the contents of the file are copied into the computers memory, and Rhino works with that data. Rhino does not do anything with the file itself until you save. Then Rhino copies the current data into the file. So in terms of Rhino it does not matter if you open a file or a copy of the file, the data Rhino is working with is the same.

[quote=“Karl_Starke, post:1, topic:46029”]
I could never delete the bottom half, which I do not want to keep. So I tried WIRECUT again on the next copy. It went through a bunch of stuff, but it still wasn’t cut. I tried to copy it, and then the program hung up, with a “Not responding” message. After trying this several more times, I had to WARM-BOOT the machine. On a successive try, I had to COLD-BOOT the machine.
[/quote]Sounds like you had multiple instances of Rhino open, each with a large amount of data, and that caused your machine to hang.


#4

All: I created a very thin plane, and issued the MeshSplit command. It worked beautifully, except for one thing…the top part of the model (the part I NEED TO KEEP) DISAPPEARED. So I did an UNDO. The bottom part was also able to be deleted.
How do I save the top part, and keep the program from automatically deleting it?

Thank you for all of your help!

Karl S.


(Wim Dekeyser) #5

There is no such thing. A plane is a planar surface that is infinitely thin - it doesn’t have thickness. So, at this point, I’m not sure what you used to split the mesh with…

The MeshSplit command should not delete anything. You select the mesh to be split and then the cutting object. If a valid intersection is found, the result should be several mesh parts.

That said, it’s not unthinkable that bad meshes do strange things.
One thing you could try to find problem areas: If you make a mesh plane and use that to intersect with your mesh object using the MeshIntersect command, you should get a closed curve or a curve that ends up at the edges of the mesh object.

Without a file, it is very hard to help…


#6

Wim: The “plane” I created was actually a large square, about 1/32" thick. That was the cutting object. The command DID delete the top part. I don’t know why. As I stated, I want to keep the top part, and delete the bottom part, which I WAS able to do, but the top part had been deleted, so I had to undo everything.

I’ll try a couple of other things, and get back

THANK YOU

Karl S


(Wim Dekeyser) #7

That would be a Box in Rhino speak.

A quick test with a mesh and a box here shows that the mesh gets split into “2 parts”. The thing with meshes is that disjoint meshes can still be joined together into “1 part”. So - in the case of a mesh being split with a box, the 2 meshes on either side of the box will still be joined together and deleting one of those will delete the other as well. In that case, the part that is inside the box - which in your case by the sound of it will be a negligible small part - is all that remains.

Note that exploding a disjoint mesh will turn this into parts that “hang together” only.


#8

Wim: I pulled out the 1/32" thick box and reversed it at 180 degrees, and tried it again. This time, the head did NOT disappear. I deleted the base…FINALLY! I am done for this evening…more later.

Karl S.


(David Cockey) #9

Perhaps MeshTrim rather than MeshSplit was used. Part of the object being split is deleted by MeshTrim.

@Karl_Starke Why use a thin box instead of a plane as the cutting object?


#10

Karl,
It seems funny to me that you have many questions and are not willing to post your drawing. There are many top Rhino users that check this forum at least once a day.
Had you posted your drawing when first asked to do so I would most likely not be typing right now. Post your drawing and you will be amazed at how soon someone will tell you why your encountering what you are.

Danny


#11

@lopacki, my glasbowl says you are right :wink:

c.


#12

My gut feeling when I read the question was that more than likely the OP has not done the basic training that comes with Rhino. I usually don`t read threads that give me that feeling…but this one has so many replies now I got curious even though the OP never posted his file for help.

I can imagine from reading the joy of success in his post that he will now rotate everything 180 degrees when he runs into a similar problem to see if it works. A path to more frustration I would think.