Add vs Subtract Solids:WEIRD BUG

[etweed]

I have a multiple extrude in which I want to cut a block out of. I created the block, selected both objects, and subtracted solids. However, it added solids solids so that the multiple extrude had the block protruding from it, although the object info pallete identifies it as a solid subtraction. I tried subtracting an even larger block from the solid subtraction, but it also added the larger block.

I had this type problem before while trying to cut a sweep, and reported it a few months ago.

A friend suggested adding solids to see if the reverse would happen, and i tried it for kicks. IT WORKED! The object has the hole i originally wanted. The object info pallete calls the object a solid addition.

If anyone else has this subtraction problem, don't rule out using add solids as a work around.

et

[Biplab]

The Add becomes Subtract and vise versa because the solids you have may be "Inside out". This kind of solid may have been created becuase of a flaw in the modeling engine that we use. In some cases, entering the solids all the way in and exiting out regenerates the solid and cures the problem.

[etweed]

Katie, I am having trouble locating "general solids" under the Model Menu or any other. Do you mean convert to 3dPolys or Nurbs or am i missing a plug in?

[Guest]

Sorry, VW 10.5 has Convert to Generic Solid. If you don't have VW 10.5, you won't see this menu item since it was new to 10.5.

If you don't have VW 10.5, after updating to 10.5 you can try that step.

But you should try Biplab's suggestion first.

[etweed]

I found Convert to Generic Solids under a "stock" workspace and tried it, but it didn't work. the subtraction still added.

I then tried moving the void-solid up and down through the solid that stays, and it still added it.

[Guest]

Before you did the solid addition/subtraction trick, did you convert the object to a general solid under the Model menu?

If you didn't, go back and try that and then do the solid subtraction using the solid subtraction menu to see if it works like it should.

If it doesn't, please send the file and a detailed description to bugsubmit@nemetschek.net

[Guest]

Did you try Biplab's suggestion?

[etweed]

I thought i had, but maybe i misunderstood. Was i to create the solids and move the solid that is to be subtracted in and out? "Exiting out" - quitting the program? please clarify if possible.

[MikeB]

What Biplab is suggesting is that you enter the solid. You do this by using the edit group command. If you use this on a solid subtraction, for instance, you access the 2 objects that created the subtraction. At this point you can edit them and then use the "exit group" command to return to the drawing area. You can use the "edit group" over and over until you access the origional 2-D polygon used to creat an extrude(for instance).

So what Biplab is saying is to enter the solid (edit group) over and over until you get the the most primitive objects. then exit the solid (exit group) over and over until you are back in the primary drawing area. This will force the solid to recalculate and may solve you problem.

Good Luck