re-anchor in parametric mode

[laughingcreek]

From time to time I have dificulties using the re-anchor tool while press-pulling in parametric mode.  I've finally come to an understanding of what is happening so I can work around it.  I still find it fustrating to use sometimes, and I think the behavior should be considered a bug.  

Here is a description of what I mean-

-create body 1

-copy body 1, making body 2

-push-pull a face on body 2.

-re-anchor the point it is measuring from (say to the oppisite face, so you can define it's lenght), and then key in a number for the length.

instead of the face being push/pulled so that body 2 has length equal to the keyed in value, the new vaule is the keyed in vaule pluse the previous value that would have been created when body 1 was defined.

that seems a bit confusing, so I made a screen cast.  Hopefully my meaning will be easier to understand-

https://screencast.autodesk.com/Main/Details/404a2223-4002-4680-ae65-231402425db9

cheers 

[laughingcreek]

Oh, and just to illustrate the need for better documentation, go to help and search for "re-anchor."  You'll find a post where it is mentioned, but nothing in terms of a command reference to describe how to use it, but that's another subject...

[zhanganchun]

laughingcreek,

Thank you for reporting the issue with so detail steps. It's a limitation for re-auchor interacting with Editing the value from Command Input in some modeling commands like press-pull. I've logged an internal issue to track that(FUS-16260). Thanks!

[jeff_strater · Accepted solution]

Thanks, Laughingcreek.  A good set of observations.

There are a couple of things going on here that are worth explaining (and is unfortunate that they are not more obvious, something we need to work on, clearly...).

First, there is Press/Pull.  By default, Press/Pull is a "smart" operation.  If the face selected is one of a few that can be idenitifed as one that can be turned into an edit operation, then Press/Pull will do that.  So, in your example you selected the termination face of a distance Extrde (Box is just an Extrude inside Fusion).  So, Press/Pull interprets the drag as editing the Extrude depth.  For a lateral Extrude face, the drag is converted into a drag of the driving sketch geometry.  If we can't track the face to something we can edit, then a new Offste feature is added.  Personally, I find the smart Press/Pull to be annoying - if I want to edit the feature, I'll just edit the feature.

Second, there is Copy/Paste of a body.  This is a feature like any other in the timeline.  That is, this feature copies the body in the state that is in at the time it executes.  So, if Press/Pull is doing its "smart" thing and editing the Extrude, the Copy feature will copy the body after it has been edited.  That's why it looks like the bodies are linked.  If you happen to pick a face than cannot be converted into a smart edit, then it will create an Offset feature at the current point in history.  In that case, the feature would be applied after the Copy/Paste, so the bodies would not appear to be linked.  Another reason why I am not fond of smart Press/Pull.

Third, there is reanchor during Press/Pull.  Reanchor started out life as a Direct Modeling feature.  In Direct Modeling, sometimes users wanted to measure an Offset from another point in the model.  But, as an operation, it was still an offset, so we subtract the added distance from the reanchor to get the "right" offset.  You bring up a very good point that, in parametric design, we should pay more attention to reanchor.  We should track the face selected face, and the adjusted difference, not just the difference.

Fourth, the last piece that you showed (entering a value in Press/Pull) is clearly a bug.  Thanks for bringing it to our attention.

Keep posting things like this, if you come across them!

Jeff Strater (Fusion development)