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Tolerance in view style

Tolerance in view style

Tolerance in view style

(OP)
What is the meaning of the tolerance in view style? Do I need to increase/decrease this value? Or let it system decide?

Thanks

NX4.0.4.2 mp10
win xp 32bit

RE: Tolerance in view style

I assume that you're referring to the 'Tolerance' for Drafting views, correct?

That being said, why are you asking whether you need to "increase/decrease" this value?  What is it that you're seeing which makes you think that it needs to be changed?

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

(OP)
As you can cee in the attached picture, this value is 4.24...
So it's just intresting what is the meaning of it. Is it milimeters? If I do not need this number at all, so why I'm seeing it and it is possible to enter any value?
 

RE: Tolerance in view style

That does seem to be a bit large.  What size drawing are we talking about? A0? A1?  

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

(OP)
In this case A2.
Does it meen, that my drafting view can be presented (ploted?) with inaccuracy of about 4mm?

RE: Tolerance in view style

It's not quite that relative, but for an A0 size drawing, I would expect the default tolerance to have been closer to 0.100 than what I see in you image.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

When a drawing view is created, the curves representing the edges of the model are inherited from the model itself, however Silhouette curves and those which need to be computed so as to have a proper hidden-line model are all done as part of the Drawing view creation and this tolerance is used to control the 'accuracy' (perhaps a better term would be how 'precise' the results are) of these curves as seen in a Drawing view and as it is plotted or rendered.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

Ok John, that is good explanation. I want to know the meaning of 'Chord Height' in reference to Silhoutte/Hidden Curves/Edges. Is it possible to show it pictorially.

RE: Tolerance in view style

Interesting.....mine is set at "0.0" also.  Is that too tight of a tolerance, and could that explain why it is taking so very long to update my drawings?

Proud Member of the Reality-Based Community..

RE: Tolerance in view style

OK, when the system generates a graphic image, particularly in wireframe, such as for Drawing views, Lines, and often Arcs/Conics, are done with graphic primitives which renders them exactly.  However for splines (and sometimes Arcs/Conics) this is usually not the case so they are rendered as a series of available graphic primitives usually 'line segments' since they are the easiest to draw and thus render the fastest.  However, there is a trade off as to how small and thus how many 'line segments' do we use to represent a free-form curve; the more segments, the 'smoother' the curve will appear, the less, the faster it will render.

So when we say 'Chordal Height' we are talking about the difference between the theoretical curve and the line segments which are being used to render it, as shown in the exaggerated image attached to this post.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

Interesting.....mine is set at "0.0" also.  Is that too tight of a tolerance, and could that explain why it is taking so very long to update my drawings?

Proud Member of the Reality-Based Community..

RE: Tolerance in view style

Interesting.....mine is set at "0.0" also.  Is that too tight of a tolerance, and could that explain why it is taking so very long to update my drawings?  

Proud Member of the Reality-Based Community..

RE: Tolerance in view style

I only change the view tolerance when lines are missing or obviously misaligned. Sometimes a smaller value actually makes it worse and you have to move to a larger value to get what you want.

Since the move to NX6, I haven't had much need to change the value. From personal experience, I have not noticed much difference in the time it takes to update the drawing whether a small or large value is used, but then again I don't believe I've ever taken it all the way down to 0.

RE: Tolerance in view style

OK, I changed the view tolerance from 0 to 0.002.......my upper-level assembly drawings (typically "E" size) are still taking over a half-hour to update (9 views).

What are the units of this variable, and can someone suggest an optimun value for a feller that typically makes "B", "C", "D", and "E" size drawings?

Proud Member of the Reality-Based Community..

RE: Tolerance in view style

....er, optimum...

Proud Member of the Reality-Based Community..

RE: Tolerance in view style

'Capnhook', what modeling unit scheme are you working in, Metric or Imperial?

If you're working in Metric I would set this to around 0.100 and if Imperial units, 0.005.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

NX 7.5.1.5

The Customer Defaults > Drafting > View > Units System is either "Metric" or "English", and does not convert when the user changes units.....?

I will try "English" at .005, and report back....thanks.

capn

Proud Member of the Reality-Based Community..

RE: Tolerance in view style

I would NOT change the setting in Customer Defaults.  If you leave it set at 0.0 (which BTW is the out-of-the-box default), NX will automatically calculate what the system feels is an appropriate tolerance based on several factors including, Drawing Units, View Scale, Drawing Scale, Model size, etc.  When I gave my recommendations above it was with respect to editing the Chord Height Tolerance on an existing drawing, NOT what you should set in Customer Defaults.

Note that if you open the Help files and search on Chord Height Tolerance and select the first result (General options) you will go to a page which explains all of this and provides examples using images similar to what I posted earlier.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

OK, help says that an "optimum" value is calculated, based on a few different variables.

So, does this "optimum" refer to optimum drawing accuracy, or optimum time to generate the drawing?  Two different requirements here ---- do I have a choice?  

Proud Member of the Reality-Based Community..

RE: Tolerance in view style

Perhaps 'optimum' was not the best choice of words as it brings to mind a sort of ideal or near-perfect condition.  Note that I used the word 'appropriate' in my explanation which I think is more suitable as it implies that it's probably a compromise between what is possible and what is recommended.  However, if you go back and read what was actually written in the Help doc's you will see that this was already more than covered when it was stated:

"The smaller the specified value the more accurate the representation. However, smaller tolerance values cause longer update times."

That should have been a clue that the term 'optimum' was speaking more along the lines of some 'happy medium'.

As for you "having a choice", if we didn't want you to have a choice, we would NOT have allowed you to override the default.  By entering some non-zero value, you are indicating what it is that your preferences are.  Now as to exactly what that value should be, since it has already been pointed out that there are many variables, you will need to experiment and find out for yourself and your situation as to what is an 'optimal' value to use.  Good luck.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

Fair enough.  If I set the value back to 0.0, and let the system decide what it thinks is the optimum value to use, would the system be able to indicate to me the value it determined, so that I might have a starting point and magnitude of this optimum value......and not need so much "luck" in trying to find this magic number?  No values I have experimented with so far have given me either optimum or appropriate results.  Top level assembly drawings are taking on the order of one-half hour to update.

Proud Member of the Reality-Based Community..

RE: Tolerance in view style

capnhook,
Do you have 'extract associative edges' toggled on in your views? If so, this may be adding to the time it takes to update.

RE: Tolerance in view style

Yes, just create your Drawing, place your Views, then select a View, press MB3, select Style... and on the General tab there will be an item in the center of the dialog labeled 'Tolerance'.  This will show the Chordal Height Tolerance used by the software for that view.

That being said, before I would start second guessing the system, I have to ask, why are you looking to change what the system thinks is 'optimal'?  What behavior or symptoms have you experienced which has led you to conclude that you needed to change the value of the Chordal Height Tolerance?

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

I don't think so, cowski.  Under " View Style > General tab > Extracted Edges ", my options are "None" and "Associative".  I am set to "None".

Proud Member of the Reality-Based Community..

RE: Tolerance in view style

Another thing to check which could be having an impact on the Drawing view update performance is to go to...

Customer Defaults -> Drafting -> View -> Threads

...and toggle OFF the 'True Hidden Line' option.

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

The 'True Hidden Line' option is and has been OFF.  I think it was one of the first options that GTAC suggested be turned off, when I was having difficulty with silhouette lines that would not update, last month.

The verrrry slow updating of my top-level assembly drawings is the symptom I am trying to alleviate, by investigating the chordal tolerance variable.......which I am now concluding that for some nefarious reason is being brushed under the rug, so to speak, insofar as the explanations I have been given as to what the optimal value for this tolerance is, and how it is magically derived and not revealed to me anywhere.

As long as I put my faith in the system, enter zero, and take the result I am given, everything will be just fine, eh?  I don't believe it.  Show me, I used to be from Missouri.

If the number is not zero, can the system report to me what value is being used, so that I have a starting point to use for weighing the trade-off between accuracy and time..?

NX 7.5.1.5

Proud Member of the Reality-Based Community..

RE: Tolerance in view style

You've already been given everything that there is to be known about the Choral Height Tolerance.  Our recommendation is to leave the Customer Default value set to 0.0 as this will allow the system to try and do what we feel is 'optimal'.  However, I suspect that there is NO setting which will be a 'magic bullet' for your situation.  Without having someone look over your shoulder at what you're doing, I don't know what else that anyone can do for you.

BTW, where are you located?  Over the next 2 months I'm going to be traveling across about half the country (Eastern half) and who knows, I might be passing close by...

John R. Baker, P.E.
Product 'Evangelist'
Product Design Solutions
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
http://www.siemens.com/plm
http://www.plmworld.org/museum/

To an Engineer, the glass is twice as big as it needs to be.
 

RE: Tolerance in view style

Can you give us an idea of the views you are working with? Number of components, relative complexity, number of views, etc.

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