Undo-ing the UNION command

[dave.dahlman]

Can I separate extruded parts (shelled) which I modified into one using the union command?

[scwegner]

Can I separate extruded parts (shelled) which I modified into one using the union command? Well, if you mean undoing as in the command UNDO then, of course, why not? If you are looking to separate them without undoing everything else, you can use the SLICE command or, if the pieces are distinct, SEPARATE

[dave.dahlman]

Unfortunately I saved the file and I am trying to "undo" what I mistakenly did a day ago. I have saved recently so my backup is not of any use. However I did try the SEPARATE command but received the following response: "The selected solid does not have multiple lumps.". This was the command I thought would help me but I don't understand the response about "multiple lumps". I have just started using 3D solids and have not encountered "multiple lumps" before. The SLICE command seems handy but not so in this case. I was hoping to be able to return to the original 2 solids I originally had before I used the UNION command. Thanks for the help.

[Mike.Perry]

Hi

Check out the following Technical Document on the Autodesk web site under the Knowledge Base section -

ID: TS44439 - Error when editing solid: 'Selected solid does not have multiple lumps' (http://usa.autodesk.com/adsk/servlet/ps/item?id=2872656&linkID=2475323&siteID=123112)

Have a good one, Mike

[jaberwok]

ID: TS44439 - Error when editing solid: 'Selected solid does not have multiple lumps' (http://usa.autodesk.com/adsk/servlet/ps/item?id=2872656&linkID=2475323&siteID=123112)

Or, in English, if your solid appears as if it could be two objects with empty space between them, it has two lumps. If it is continuous, it doesn't. "Separate" only works on solids with two or more lumps.

"Slice" is going to be your primary option. If need be, make a copy of the solid, Slice or Subtract some bits from the copy and different bits from the original. Then move the copy back to where it should be.

Have fun. :smile:

[dave.dahlman]

Thanks John. It appears that my solid is continuous and there is only one lump. Therefore the SEPARATE command is of no help. I should have used the INTERSECT command initially on a copy of my (2) original solids, then after moving that solid back I would have been able to SUBTRACT the area of intersection. And finally by using the UNION command, I would have created one solid from the previously modified solids. The order of the commands is crucial or you can paint yourself into a corner. Thanks again.

Dave

[scwegner]

I'm not sure what kind of pieces you're talking about, but it may help you to keeps parts separate and block them together instead of using union. Or, if it's all supposed to be one complicated piece, I often make copies of progressive steps until that part is finished so that I have something to go back to.