how do you create an offset surface?

dave_cowden

I would like to create a surface that is an offset from another one ( either a face or a surface). 

I have found offsetFace-- but this moves the face, instead of creating a surface.  This seems like something that should be possible, but I can't find it...

thanks as always.

NeilCooke

Dave, there is now an extractSurface command. You could thicken the face you want then extract the offset face? Not tried it but should work. 

kevin_o_toole_1

Sorry about this!

opExtractSurface is currently under development, since we're using it extensively in the sheet metal functionality that's also under development. It's not exposed to end users right now because we might be changing the way it works, and when we do this we don't want to break existing users' documents or have them fail to upgrade.

Sadly, I can't think of an alternative that gives you this functionality, but I can say that eventually we will be making opExtractSurface user-facing, and when that happens you will be able to do exactly what you're asking for.

john_f_carr

With the release of sheet metal, opExtractSurface should be available to all.

NeilCooke

Dave, there is now an extractSurface command. You could thicken the face you want then extract the offset face? Not tried it but should work. 

dave_cowden

Good tip, thanks! That could work. But how do i go about thickening the face, then extracting the surface, but then removing the thicken so i dont affect the underlying geometry?  
    * 

dave_cowden

well poop, that doesnt work-- because i guess you cannot call that if you are a 'regular user':




  

Any other ideas?

kevin_o_toole_1

Sorry about this!

opExtractSurface is currently under development, since we're using it extensively in the sheet metal functionality that's also under development. It's not exposed to end users right now because we might be changing the way it works, and when we do this we don't want to break existing users' documents or have them fail to upgrade.

Sadly, I can't think of an alternative that gives you this functionality, but I can say that eventually we will be making opExtractSurface user-facing, and when that happens you will be able to do exactly what you're asking for.

dave_cowden

Unfortunate. this is a pretty major limitation.

Larry_Canipe

Has anyone found a way to just do a surface offset. I have yet to find a way to just have the part surface from the model. 

dave_cowden

Hi, @Larry_Canipe

I ended up writing a featurescript to do it. You're welcome to try it out.

https://cad.onshape.com/documents/323312569b42b381b93ee95c/w/4feba228409d550cfecc4193/e/4f18ff5b4caf83cc9e65fee9

tim_waldemer

First do a transform on the subject surface using the copy in place rule.  Then temporarily hide your original surface.  Lastly, do a move face on the surface using the offset rule.  This gives you a true offset surface while keeping the original surface.  Hope this helps.

john_f_carr

With the release of sheet metal, opExtractSurface should be available to all.

kevin_o_toole_1

John is correct, but just a point of clarification: 

These functions are still marked @internal because we may change their behavior slightly (especially with respect to error handling) in the future. This means that the next time you update the FeatureScript version of custom features created on top of these functions, individual features may behave differently (or fail) when they update their links.

The functions are useful enough that they were worth exposing anyway, but be aware that changes are a possibility. Here's a doc where you can play around with some of the current behaviors:
https://cad.onshape.com/documents/dcbffeaede71bbfd8d37fc83/w/3ba91b4bc06d0a60cc11d2a5/e/9e9ed0e174274eeac7d26ac7

Chris_D_Mentes_001

FYI I seem to be using the function succesfully now so if anyone is trying it out just copy and paste the format from the std library source for Offset Surface

S1mon

Offset surface has been available as a standard feature for a while.

https://cad.onshape.com/help/Content/offset_surface.htm

And yes, it’s also available for use in FeatureScript. 

https://cad.onshape.com/FsDoc/library.html#opOffsetFace-Context-Id-map