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Approximate Surface Offset - WF5 ?

jeff4136

New member
In ...
[url]http://www.mcadcentral.com/proe/forum/forum_posts.asp?TID=38 016&PN=1&TPN=7[/url]
... I saw a reference to a new approximate surface offset option. Sounds
interesting. How does it differ from the existing offset options? If
someone with a copy of WF5 feels like contrasting the differences or
working up what they feel like is a good representative example and posting
a neutral I'd be interested in seeing it...
2008-11-19_073635_ctrld_fit_ofst--wf2--.prt.zip

... and appreciative.
-TIA
 
I'm keen to see some improvements in this area. According to [url]http://www.ptc.com/appserver/wcms/relnotes/note.jsp?&im_ dbkey=77915&icg_dbkey=826[/url] the improvements are:

-------------------


The special handling capabilities of surface offset are improved:
<ul>[*]In addition to excluding patches during the offset, you can choose to approximate these patches.[*]When you cannot offset an internal patch of a quilt due to minimum
radius restrictions, Pro/ENGINEER attempts to approximate that patch
with a single surface.[*]You can choose which patches to exclude and which to approximate, and whether or not to attach the approximated patches.[/list]--------------------

Sam
 
> You can choose which patches to exclude and which to approximate,
> and whether or not to attach the approximated patches.


Ah!


So if I understand correctly; if a single surface within a quilt
goes self-intersecting due to a radius of curvature smaller than the
offset value you can chose to approximate just that surface while
the remaining surfaces are done as standard surface normal offsets.


I like the sound of that.


Thank you, Sam (and for the link, as well).


If anyone wants to give it a whirl on the file above (1" will make the
'nose' fail) and post a neutral, feel free. ;^)
 
I played a little with this function but I think I'm missing something: I tried to set up a very simple part, just a surface made out of tangent arcs:



Too much offset cause the middle part of the quilt to disappear:



But then if I define the central portion as "approximate", hoping for some sort of blend between the surfaces, I obtain this:



And, like in Ghostbusters, I think this is "bad" :O

Paolo
 
I've just tried the same thing in Wildfire 4.

The green was the original seagull shape, the red the normal offset and the blue the automatic offset.



As with your Wildfire 5 model, the middle quilt just disappears with a normal offset and gives me a geometry check error.

The automatic offset is approximate, but at least it is not totally out.

I'd be interested to see what Wildfire 5 does with a surface like that shown below in yellow. The Wildfire 4 normal offset is shown in grey, and its not too good. The automatic offset looks reasonable but is not accurate enough for most practical applications.



Sam

Edited by: SW
 
SW said:
I've just tried the same thing in Wildfire 4.


As with your Wildfire 5 model, the middle quilt just disappears with a normal offset and gives me a geometry check error.

The approximate is indeed approximate, but at least it is not totally out.

Hi Sam, in your example you used approximate for all the parts of the quilt, or only for the central portion? I thought the use of approximate was for only that portions of quilts that don't work well in normal mode...
 
Im not a fan of anything which uses the term "approximate". I want to engineer accuracy. This is another fancy tool like Warp which will be used 1% of the time lol.
 
I used automatic offset on the whole quilt. I could exclude the central portion and offset the "wings" normal, giving me intersecting surfaces, but then an automatic offset on the central portion doesn't work at all. I was thinking Wildfire 5 might do something clever as the description suggests, and allow selected patches to be approximated then blended to the main quilt.

As for engineering accuracy, if a surface can't be offset normal everywhere, it is a function of the geometry, as I understand it, all I can do is change this original geometry so the offset is possible. However, if I can't increase the radii, I might be able to use some engineering judgement and allow offset distance to vary around specific areas where I don't anticipate mould flow problems or whatever else.

What would be useful is functionality, especially within style, that allows the offset requirements to be applied to a quilt, and then prevents the surface from being manipulated in a way that would contravene these requirements.

Sam


(I've just updated my post to use the correct Pro/E term of automatic instead of approximate, although automatic to me suggests a bit more confidence than is justified.)
 
This is the IGES file with both surfaces, the "approximate" surface is very, how can I say... "wavy", and the worst part is that if you look at the TOP view, the outline is not "straight" but is protruding... Looks like a cloth :O


2009-01-14_101646_prt0002.zip
 
> This is the IGES file with both surfaces


Thank you, Paolo.
If that's as good as it gets; that function is way too 'Autodesk' for me.
smiley18.gif
 
Problem

i won't be able to change the design or the curve on my model as it's already fix. I realized that I could not offset the surface more than 0.5 mm (normal to surface). Also, wouldn't be able to use the automatic fit option because of accuracy needed. Is there any other way that I can work around besides changing the curve itself?



I used automatic offset on the whole quilt. I could exclude the central portion and offset the "wings" normal, giving me intersecting surfaces, but then an automatic offset on the central portion doesn't work at all. I was thinking Wildfire 5 might do something clever as the description suggests, and allow selected patches to be approximated then blended to the main quilt.

As for engineering accuracy, if a surface can't be offset normal everywhere, it is a function of the geometry, as I understand it, all I can do is change this original geometry so the offset is possible. However, if I can't increase the radii, I might be able to use some engineering judgement and allow offset distance to vary around specific areas where I don't anticipate mould flow problems or whatever else.

What would be useful is functionality, especially within style, that allows the offset requirements to be applied to a quilt, and then prevents the surface from being manipulated in a way that would contravene these requirements.

Sam


(I've just updated my post to use the correct Pro/E term of automatic instead of approximate, although automatic to me suggests a bit more confidence than is justified.)
 
@Fsbaharu - can you upload a .prt or a pic of your model? How familiar are you with the analysis tools?

You might want to consider starting a new thread regarding your issue.

//Tobias
 

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