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X-Form: surface poles associated to points

Genius
Genius
In a previous thread, @Sandman taught the technique of associating surface poles to pre-fined points.
 
Here I observed an odd thing about X-Form.
 
As shown below, I created a 2×2 face, X-Form/dragged its poles to be coincident with the ends of four lines. When I changed the lengh of the lines, the face did change with them. But under the feature X-Form, there is no patents of lines listed! And the lines have no children!
 
Is there anything wrong? Thanks!
 
Image.png
 
Image.png
6 REPLIES

Re: X-Form: surface poles associated to points

Phenom
Phenom
@surfactant,

X-Form is an edit not a feature - says it plain as day in the documentation. The parent of the X-Form is the original face, not the reference points used to complete the edit of that face.
-Tim

Re: X-Form: surface poles associated to points

Genius
Genius

Hi @TimF   Thank you!  In this example, I did make the poles contrained to be coincident to the line ends. But there seems to be no way to SEE those constraints except by observing the real model update.

Re: X-Form: surface poles associated to points

Phenom
Phenom
@surfactant,

Show me on the dialog or in the documentation where the word constraint appears in reference to using X-Form. You did no such thing - you moved surface poles to the endpoints of lines using Snap Point. Turn off Snap Point and you cannot do this - therefore there are no constraints.

There are no parameters or expressions therefore it's not a feature and has no children other than the original face. It really is as simple as that. It's a glorified edit that shows up in your Model Navigator like a feature so that you can see that SOMETHING was done to a surface and if you wish to change it further, you can do it via that original X-Form rather than adding more X-Forms.

Now, I will give you props in that X-Form is not behaving consistently between this example and the half-baked example you had where X-Form was an edit with nothing changing (which is odd, but I see your point I guess). I would suggest you call GTAC to get that looked into if you really think it's necessary since most users aren't going to add commands that result in nothing geometrically changing (like adding Taper with 0°).
-Tim

Re: X-Form: surface poles associated to points

Genius
Genius

Hi @TimF   Thank you for your detailed comments!

 

I don't know what you mean by "there are no constraints". The surface did change when the lengh of the lines changed. This makes me able to control a B-surface just as controlling a B-spline pole by pole.

 

Image.pngImage.png

 

As to the inconsistency of X-Form, I think that's very fundamental way of how X-Form works, but not an issue that can be fixed easily. Therefore let me forget it. 

 

Thanks again!

Re: X-Form: surface poles associated to points

Phenom
Phenom

@surfactant,

 

I'm simply pointing out that when you stated "I did make the poles contrained to be coincident to the line ends" that you were not technically constraining anything because constraints do not exist in the X-Form command.  If they don't exist, why would you use those words?  That's what I mean.  In the end, you're simply editing a surface or spline with that command and the ONLY parent will be the source spline or surface - no lines used as reference.  While it might be ASSOCIATIVELY updating, there certainly aren't specific constraints (think Sketch and Assemblies).

 

 

You seem hung up on the lack of children - I'm simply also explaining WHY there aren't any children - X-Form is an edit, not a feature.

 

I cannot explain why it's not behaving as you expect - you will have to contact GTAC with similar examples to point out what you feel is inconsistent behavior.

-Tim

Re: X-Form: surface poles associated to points

Genius
Genius

Hi @TimF   Your comments make me understand X-Form much better. This is would be very helpful for handling the command in a better way. Thank you!