Surfacing Course : Q & A ?

[[-Skint-]]

Hi All,


Just thought I would share with you that I am attending a 3 day Surfacing Course using Wildfire 4.0. Dates are 2nd, 3rd & 4th of July ( Yep 2008 ).


I have not had much need with surfacing due to the nature of my businessand as always not much free time to practice, however lately I have the desire to learn more & more of this wonderful Pro-e Program

.


I have started to mess around ( lunch breaks etc ) with surfacing and I now share many of the frustrations with some of you people. I understand much more when reading Maudib`s thread now. Surfacing can be very tricky at times, frustrating, long winded and painfully thought provoking when something goes wrong. I have started to enjoy working with them though and can now fully understand thier capabilities and thier strengths. Anyway.......


SO... I thought it may be of interest to some of you who may not be able to attend these courses, and offer you the chance to give questions, theory`s, comments etc. I will try my best to fit them into the three days I have with the Pro-Pro`s.


If anybody has any questions they would like me to ask then please list here and I will do my best to get them answered for you. NOT promising anything though !


The gentleman giving me the training is pretty laid back and I will be asking many things, surfacing and not, so feel free to ask away

Skint - The Surfacing Pro

 

[[-Skint-]]

One of my first questions, thoughts :


I have modelled something which contains surfaces that have been both Merged and Trimmed. Once i have patched them all together and Solidified the complete part, I am able to hide everything from Boundary Blends, Merges etc. Why is it that the Trim commands are unable to be hidden ?


( Told you I was new to this

)

 

[csusie]

You dont hide the operator features only the features that actually create the surfaces.

 

[Jacoolo]

I assume You attend to "Designing with Surfaces" or "Advance Surface Modeling" - it is good step to start, but if You expect to learn soemthing about real tricks for this stuff, well then You miss the course.

I noticed, PTC divides Surfacing on two parts - Pro/Surface and ISDX.

With the first one You are going to learn tools. With a second one, You are going to learn tricks(but not enough to be worth to pay for it))

I wish to have this mixed and more focused on tricks rather than tools.That is my wish.

If I were You I would ask mostly about VSS - all things related to references - Normal to Surface, X traj, etc - Boundary Blend(), Analisys(dihedral angle, gausian curvature - why, what, when) and spline in sketcher.

Try Your instructor if he is aware of some trick Jeff share in this forum(curvature constraint, equations for curvature for one end of spline)?

 

[tobbo]

Great thread!!I hope that there will be a lot of people taking this opportunity to ask hard questions!!


Ihave been working whit surfaces for about 15000 hours so far, and my only tip is : if you really want to learn surfacing , go to Bart Brejcha and take his "one week surfacing class" at design engine. I appriciated that course much more than ptcclasses.At his place,you will learnsome tips and trix that Ptc doesn

 

[[-Skint-]]

Hey Jacek, Yeah VSS will no doubt be near the top of my list. I really need to learn some tricks with that tool !! The 3 days will be pretty casual, and the instructor has asked me to list anything that I would like to include within the 3 days, as he knows I am going to get some practice in before the course

. This forum ( your thread especially ) is a great resource and I hope to kick his ass with good questions when I get there haha.


I dont intend to get into ISDX to be honest. I believe ( and hope ) that even the most complex surfaces can be created with the standard commands. I dont often develop parts based on asthetics only, everything I create has to be Manufactured to tight tolerances and I figure that ISDX is not really geared to that ? Besides, I want to be able to create everything using the basic functions as I believe it would give me a better understanding of surfaces before delving into ISDX. I would like a play with it one day though !


Tobbo, welcome to MCAD

. I would love to have the spare cash & time to pop over to see Bart`s course. I know he is one of the proper users of Pro-e and could certainly teach us all a few things !! He seems a nice chap too, so if anything I would like to pop over and buy him a beer or three

Hopefully there will be some decent questions I can pose, even from the more experienced users who may just want to " pick his brains ".

 

[Jacoolo]

as far as You are not focused on industry design rather on creating housngs for valves this course should introduce right tools for Your needs.

From my point of view, in this scope of use of the surfacing capabilities of Pro/e most worth are : VSS, Offset tool - replace surface, expand, offset with draft - Copy(intent chains, seed and boundary options), merging and patterning issues for quilts(great solutions from jeff at the begining of "Some surface...."), graph tool, analisys(why the hell thicken option just does not go - i.e dihedral angle between adjacent surfaces is more than 0.5)

But it(introduction to Surfacing) lacks tricks which show some major issues one can meet - maintaining tangency between surfaces, way to "see" shapes(recognizing what are the core surfaces, what are the final, detail ones)

 

[[-Skint-]]

Q aboutVSS: Is the "use edge" command as accurate as it should be ? I use this feature quite a lot, especially in the sketcher environment when creating parts etc, however....


....When creating a Variable Section Sweep, I am finding I get slightly defferent results when A: creating the sketch from scratch and B: using the edge of an existingcurve for the sketch. So is it always better to create the sketch whilst in VSS command and to NOT copy the edge of an existing curve ?


Jacek, sorry I meant the curves.

Edited by: [-Skint-]

 

[Jacoolo]

I suppose Jeff is going to introduce richer info but - in general - You are not able to create VSS with variable section using Use edge tool

 

[[-Skint-]]

Sorry if this is a bit of a noob question, but Im just curious more than anything as to how people go about trimming / merging surfaces and if there is a best practice of doing so.


Q. When creating a surface purely for trimming an existing surface, imagine you needed to create a 4-part boundary from a 3-part boudary curve for instance... Do you create the trim surface using exact pre-defined references such as Datums or edges of geometery ( See Blue Surface below )...OR...


.. Do you create the trim surface "any old " way and extrude beyond the trimmable geometery. Aslong as you have the intended trim shape in the correct place, do you allow the actual trim surface to protrude past any specific references ( See the Purple surface below ).


For my practice, I tend to use the 2nd option more. Just wondering if its bad practice ?






Edited by: [-Skint-]

 

[dgs]

Skint - Two things:


First, break yourself of using edges all the time. They are less 'stable' than model surfaces and can create unwanted parent child relationships. Rounds, for example, create new edge IDs because the trim the edge length. When you use that edge, you make the feature a child of the round. A bit hard to explain. I tried to uplaod a file that showed the difference, but the upload failed it seems. PM me and I can email it.


Using edges in a VSS can produce odd results. What Pro|E will do is recreate the section at each point on the trajectory using those edges, wherever they are in relation to the trajectories at that point.


Second, I tend to use the method on the blue surface. The reason is that it will grow as the yellow grows. The purple is built with dimensions that have no bearing to my design intent. If the yellow surface grows past the purple, my model will fail even though making the purple a little longer would work just fine.


If the yellow grows far enough 'upward', that arc in the blue will eventually fail, but that's good as it signals that I have a problem with my design intent that I need to resolve by either altering the section of the blue surface or changing the dims of the yellow. Model failure then signals a design problem, not a modeling problem.
Edited by: dgs

 

[[-Skint-]]

I suppose Jeff is going to introduce richer info but - in general - You are not able to create VSS with variable section using Use edge tool

Hmm Im sure I managed to make this work before, but it seems I cannot now lol.


So why is it that we can use pre-defined curves for the trajectories but not the section? I find that a little strange too. I am using the "constant to normal" direction setting and selecting the plane which my section sketch is on, but I still have to redraw the sketch. Wierd ?

 

[[-Skint-]]

Skint - Two things:


I tend to use the method on the blue surface. The reason is that it will grow as the yellow grows. The purple is built with dimensions that have no bearing to my design intent. If the yellow surface grows past the purple, my model will fail even though making the purple a little longer would work just fine.


If the yellow grows far enough 'upward', that arc in the blue will eventually fail, but that's good as it signals that I have a problem with my design intent that I need to resolve by either altering the section of the blue surface or changing the dims of the yellow. Model failure then signals a design problem, not a modeling problem.

dgs, yeah how silly of me. I should or realised that straight away. I guess it has just not " failed " on me just yet haha. Great explanation though, I get it !!


Pm sent rgds the copy edges.

 

[Jacoolo]

]

I suppose Jeff is going to introduce richer info but - in general - You are not able to create VSS with variable section using Use edge tool

Hmm Im sure I managed to make this work before, but it seems I cannot now lol.


So why is it that we can use pre-defined curves for the trajectories but not the section? I find that a little strange too. I am using the "constant to normal" direction setting and selecting the plane which my section sketch is on, but I still have to redraw the sketch. Wierd ?

oh, yes You can use them. I would be far from saying, you can`t. But - have a one issue in mind - VSS does not let You obtain results with variable section only with constant one( set - Options > Constant Section)

Sometimes if Your refernces - trajectory, entities for X dir, for Normal direction are set wrong, Pro/E does not let You end up with any results. Ussualy it won`t let You dive into sketcher

According to Your question about trim - this is sh*ty case every time I merge surfaces. Generaly - both surfaces should always intersect each other. Second, they should intersect on the whole length(or have closed section).

When You have a situation with yellow surface Pro/E usually is able to do this but as an additional results You gonna obtained Geomcheck warning because Pro/E extended surface

 

[[-Skint-]]

Ive decided that .. to learn more surfacing I am going to choose an item from my home and start to model, using Only surfaces. So last night, I took my snowboard bindings off my board and took one completely to pieces, screws & all !! Got to work early this morning to spend 45 minutes on the start.... left the binding parts at home

.


Moral of the story, a good surfacer requires an awake brain

EDIT : They dont look too complicated from these pics, but trust me..there isnt one straight edge on the damn things

. Should make for an interesting modelling lesson.



Edited by: [-Skint-]

 

[Jacoolo]

if You had choosen "rights" shoes and arrived to right "job" then I can say You aRE AWAKE ENOUGH)

I remind mysef playing AvP 2 till 5 am and then coming to job and sit bythe desk. The point is, it wasn`t mine)

I think You should ask about solving rounds cases which this course should cover with enough tools to bite the case

 

[[-Skint-]]

Jacek, AvP2 until 5am... ouch you must be tired haha

You playing that on PC or console?


Rounds are always a good talking point arent they, they are so unpredictable ! If you have any models, such as the one above, that illustrate how rounds can act so differently then please do mail me, I will get the point across that Rounds need Work for WF5

 

[Jacoolo]

]

Jacek, AvP2 until 5am... ouch you must be tired haha

You playing that on PC or console?

on PC, 2 -3 years ago. Nice games but only with melisa. In other way my stomach refuse to attend with such activity(to much up and down and aliens tended to appear in the most not expected moments). Yeah, one collegue of mine wrote even an article about Alien Breed and AvP. Good piece of stuff.

Concerning round issue - I gonna do something for You in this direction.

 

[[-Skint-]]

]


Jacek, AvP2 until 5am... ouch you must be tired haha

You playing that on PC or console?

on PC, 2 -3 years ago. Nice games but only with melisa. In other way my stomach refuse to attend with such activity(to much up and down and aliens tended to appear in the most not expected moments). Yeah, one collegue of mine wrote even an article about Alien Breed and AvP. Good piece of stuff.

Concerning round issue - I gonna do something for You in this direction.

I remember both of those games very well on the PC. Alien breed I remember from Many Many years ago, a fantastic game. Both the the AvP games were incredibly atmospheric at the time of release, not sure how I would think about them now after playing my xbox360

As for pro-e, any help and questions are appreciated. I want to make the most of this up-coming 3 days.

 

[Jacoolo]

well, I can only dream about X360) - I`ll wait till my kids are old enough and buy one

Concerning You surfacing course - Push Your instructor to clearify all aspects of curves, curvature and transitions(G0, G1, G2)